Integrated Pest Management

Integrated Pest Management Evonne Gong

Integrated Pest Management (IPM) is the coordinated use of pest and environmental information to design and implement pest control methods that are economically, environmentally and socially sound. IPM promotes prevention over remediation and integrates multiple control strategies to achieve long-term pest management solutions.

IPM is a decision-making strategy based in systematic observation and documentation of crop health and environmental conditions. Preventative measures are built into the production system in anticipation of potential issues. Actions are taken in response to established thresholds, and results are documented.

Preventative and curative control methods are built into an IPM management plan for each pest, crop, and farm. Pesticides are used when additional control measures beyond the following methods are required.

Much of the space in this publication is dedicated to lists of pesticide options for weeds, insects, and diseases on specific commodities. Effective pest management involves much more than using pesticides. Always review the summary paragraph(s) under each pest listing for preventative pest management methods and specific decision-making techniques before reaching for a pesticide. For detailed information on IPM, visit your local Extension system's IPM web site.

Abstaining from use of pesticides. Some growers choose to completely forgo the use of any kind of pesticides, be they conventional, biorational, or certified organic. While this strategy avoids possible detrimental effects to native natural enemies of pests and can save money on equipment and materials, it can lead to the buildup of very high populations of pest species. It may also affect neighboring farms by providing a sanctuary for pest populations. 

Diagnostics for Plant Problems

Diagnostics for Plant Problems Evonne Gong

Correct diagnosis of a problem and correct identification of the pest (insect, disease, abiotic factor, nutrition, etc.) causing the problem are key to successful crop management and profitability. Below is a list of laboratories that offer disease diagnostics on a fee-for-service basis. When submitting a sample, remember to specify whether you are looking for insect, disease, or weed (or other) identification in case more than one organism and/or symptom is present on your sample. Also, provide as complete a description of the problem as possible including crop, symptoms, distribution within the field or greenhouse, and unique characteristics of the location. Commercial growers will receive different recommendations than home gardeners. Please indicate if you are an organic grower. In general, virus screening is limited to a small group of common viruses; further analysis is  referred to specialized laboratories. Contact your local  lab or your state Extension Vegetable Specialist for more information.

In order to submit a sample for diagnosis, some basic preparation instructions should be followed, including:

  • Collect specimens that show a range of symptoms (i.e., from healthy to severely affected), usually collected from the margin of the affected area. Avoid specimens that are completely dead or decayed as they are not diagnostically useful.
  • Fill out the sample submission form provided by the lab. This is very important. Without detailed information about the problem, a correct diagnosis is very difficult.
  • Pack specimens in dry paper and place in a plastic bag (never pack with wet paper towels or add water).
  • Mail specimen and submission form using same-day or overnight delivery or deliver specimen personally the same day. If this is not possible, place in a refrigerator and mail or deliver the following day. Specimens should come to the diagnostic labs early in the week to avoid problems with weekend holdovers.

Plant Diagnostic Clinics of New England

(D = plant disease identification, I = insect identification, N = nematode analysis, W = weed identification)

Connecticut

UConn Plant Diagnostic Lab (D,I,N,W)

Ratcliffe Hicks Building, Room 4
1380 Storrs Road, Unit 4115
Storrs, CT 06269-4115
(toll free) 1-877-486-6271
https://plant.lab.uconn.edu/
Cost:  $20

The Plant Disease Information Office (D,I,N, W)

The Connecticut Agricultural Experiment Station
Jenkins-Waggoner Laboratory
123 Huntington Street, P.O. Box 1106
New Haven, CT 06511
www.ct.gov/caes
(203) 974-8601; (877)855-2237 toll-free outside New Haven area
Cost: No fee (CT residents only)

 

Maine

Plant Disease Diagnostic Lab (D,I,N)

Pest Management Unit
17 Godfrey Drive
Orono, ME 04473-3692
800-287-0279 (within Maine) or (207) 581-3880 (outside Maine)  fax: (207)581-3881
www.extension.umaine.edu/ipm/ipddl
Cost: $18 for Maine residents, $38 for out-of-state residents

 

Massachusetts

Plant Disease Diagnostic Laboratory (D,I,N,W)

UMass Extension Plant Diagnostic Lab
#3 French Hall, 230 Stockbridge Road
Amherst, MA 01003
(413) 545-3208 fax: (413) 545-4385
http://ag.umass.edu/diagnostics
Cost: $50

New Hampshire

The Plant Diagnostic Lab (D,I,W)

Barton Hall
34 Sage Way
Durham, NH 03824
(603) 862-3043 
https://extension.unh.edu/programs/plant-disease-diagnosis-services
Cost: $20

 

Rhode Island

Plant Diagnostic Lab (D,I,W)

URI Cooperative Extension
3 East Alumni Avenue
Kingston, RI 02881
(401) 874-2900  fax: (401)874-2259
https://web.uri.edu/coopext/ppc/
Cost: $20

Vermont

University of Vermont Plant Diagnostic Clinic (D,I,W)

201 Jeffords Hall,
63 Carrigan Drive
Burlington, VT 05405
(802) 656-0493 fax: (802)656-4656
https://www.uvm.edu/extension/pdc
Cost: $15 (VT residents only)

Pesticide Safety

Pesticide Safety Evonne Gong

Who Can Apply Pesticides

Farmers who use pesticides may require pesticide applicator licenses or permits according to state and federal law. It is important to check with your state lead agency to determine what is appropriate in your state. In general:

  • Farmers who apply restricted-use pesticides on their crops need to have a private applicator license or permit.
  • Workers who help someone who is licensed or certified to apply restricted-use materials may also need a license to assist. 
  • Farmers who use only general-use pesticides may also require licenses or permits; these requirements vary from state to state.
  • In most states, commercial (for hire) applicators must follow rules that are more restrictive than those of private applicators. 

Please note that the requirements of the EPA Worker Protection Standards (WPS) must still be followed regardless of whether a pesticide license or certification is required. See the section below on WPS. As of this printing, the following are contacts who can provide information on specific requirements for pesticide licenses and certification for each state.

Warning! Pesticides are poisonous. Read and follow all directions and safety precautions on labels. Handle carefully and store in original labeled containers out of reach of children, pets, and livestock. Do not use concentrations greater than stated on the label. Do not apply more pesticide per acre or more frequently than the fewest number of days between applications recommended by the label. Remember that the pesticide label is a legal document. If you do not follow the label directions implicitly, you could lose your applicator's license or be fined.

Pesticide Registration

Pesticides require both federal and state registration. Pesticides in this publication have been reviewed for federal registration status and are current at the time of publication. State registration status has been reviewed for most products, but state registrations are renewed annually and may be subject to change. Each New England state maintains a registration database, which can be found at the following websites:

Maine
Maine Board of Pesticides Control
http://npirspublic.ceris.purdue.edu/state/state_menu.aspx?state=ME
Searchable database

New Hampshire
Division of Pesticide Control
http://agriculture.nh.gov/divisions/pesticide-control/registration.htm
Contact Director of Division of Pesticide Control for information

Vermont
Vermont Agency of Agriculture, Food, and Markets
http://www.kellysolutions.com/vt
Searchable database

Massachusetts
Massachusetts Pesticide Product Registration Information
http://www.kellysolutions.com/ma
Searchable database

Connecticut
Connecticut Department of Energy and Environmental Protection
http://www.kellysolutions.com/ct
Searchable database

Rhode Island
Department of Environmental Management
http://npirspublic.ceris.purdue.edu/state/state_menu.aspx?state=RI
Searchable Database
Select 'Registered Pesticides' link for list
 

Understanding Pesticide Labels

A pesticide is referred to 1) by a common name, which is also the name of the active ingredient (AI), or 2) by a trade or brand name (trade names are capitalized in this guide). Trade names are used in the guide for identification only; no product endorsement is implied, nor is discrimination intended against similar materials.

Labels Are for Your Protection and Information. Look for the percentage (by weight) or amount of material in the formulation. Compare costs of two similar products on the basis of effectiveness, the amount of actual pesticide contained, and the quantity of the formulations needed/acre.

Labeled Formulations. The examples of pesticide products that are listed under each crop within this publication give only one formulation and one trade name. Often there are other formulations and trade names with the same active ingredient. Growers should be aware of other formulations and products. Consult the tables in Disease, Insect, and Weed Management Sections (Tables 2627, and 29) for lists of formulations and products. The rates to be applied are on the label.

NOTE: There may be several products registered with the same active ingredient. Each label is different, and some crops may be listed on some labels but not on others. Always be certain the crop is listed on the product label before ordering or using the product.

Restricted-use Pesticides. In accordance with federal and state pesticide regulations, those pesticides that are highly toxic and those that persist and accumulate in the environment are placed on a restricted-use list and shall be sold and used only by certified applicators. For information about training for certified applicators contact your Extension Specialist or the offices listed above. In some instances, states may require additional permits for certain pesticide users.

Control of Target Pest Not on the Label. Always be certain the crop is on the label before using a pesticide on that crop. Target pests not listed on the label may not be effectively controlled by that product.

Tank Mixture and Aerial Application. Check the label and consult your state pesticide regulatory agency.

To Avoid Illegal Residues. Adhere strictly to preharvest intervals. Accurately calibrate your equipment; never exceed label recommendations. Prevent drift to adjacent properties or crops, or contamination of bodies of water. The applicator is held responsible for problems caused by drift or contamination. High-volume, low-pressure, ground applications cause less drift than low-volume, high-pressure, air-blast, ground applications, aerial applications, or dust.

Disposal of Pesticides. Read label. For current instructions on regulations and guidelines pertaining to the disposal of chemicals, contact your State Lead Agency for pesticide regulation located in either the state Department of Agriculture or state Department of Environmental Protection. The Pesticide Stewardship Alliance (TPSA) has a pesticide disposal database with resources for each state. Visit their website at https://tpsalliance.org/resources/state-disposal-map/. Triple rinse empty containers; dispose of them carefully and properly.

It is the responsibility of the user to read the label and be sure that the material selected is labeled for the proposed use. Similar pesticide products may not have the same crop uses.

Pesticide Toxicity. All pesticides are poisonous. However, some are more toxic than others. The toxicity of the pesticide is usually stated in the precaution label. For example, a skull and crossbones figure and the signal word "Danger" are always found on the label of highly toxic (Toxicity Class I) materials. Those of medium toxicity (Toxicity Class II) carry the signal word "Warning". The least toxic materials (Toxicity Class III) have the signal word "Caution". The toxicity of a pesticide is expressed in terms of oral and dermal LD50. LD50 (lethal dose 50) is the dosage of active ingredient that kills 50% of test animals (usually rats or rabbits) with a single application of the pure pesticide for a given weight of the animal (mg/kg of body weight). The lower the LD50 value, the more toxic the material. Oral LD50 is the measure of the toxicity of pure active ingredient when administered internally to test animals. Dermal LD50 is the measure of the toxicity of pure active ingredient applied to the skin of test animals. Generally, an oral application is more toxic than a dermal one. Dermal and oral LD50s for each of the fungicides, insecticides, and herbicides listed in this guide can be found in Tables 26, 27, and 29, respectively. 

The Worker Protection Standard and Who Must Comply

Pesticides can be useful tools for farmers. They can also be deadly. Exposure to pesticides can cause physical harm, debilitation, and even death. Not only applicators are at risk. Family members and workers can also be harmed due to improper storage and use of pesticides.

For this reason, the EPA has developed the Agricultural Worker Protection Standard (WPS) for Pesticides (US EPA regulation, 40 CFR Part 170). The WPS applies to all pesticides that are used in the production of agricultural plants on farms, forests, nurseries, and greenhouses. This includes general use pesticides including those allowed in organic production (OMRI-listed), as well as restricted-use pesticides. Also, even if a pesticide license is not required, employees and handlers must still receive education in and comply with the WPS.

The WPS requires the owner or employer to take steps to reduce the risk of pesticide-related illness and injury: 1) if pesticides are used on the farm or 2) workers or pesticide handlers are employed who may be exposed to such pesticides.

You will know a pesticide product is covered by the WPS if you see the following statement in the "Directions for Use" section of the pesticide labeling:

Agricultural Use Requirements

Use this product only in accordance with its labeling and with the Worker Protection Standard, 40 CFR Part 170. This standard contains requirements for the protection of agricultural workers on farms, forests, nurseries, and greenhouses, and handlers of agricultural pesticides. It contains requirements for training, decontamination, notification, and emergency assistance. It also contains specific instructions and exceptions pertaining to the statements on this label about personal protective equipment, notification of workers, and restricted-entry intervals.

The primary WPS resource is the How to Comply manual (https://www.epa.gov/pesticide-worker-safety/pesticide-worker-protection-standard-how-comply-manual), developed by EPA. The manual is available from your State Lead Agency, pesticide education office of the Cooperative Extension Service, the EPA Region 1 office, and EPA's National Agricultural Compliance Assistance Center. Every agricultural producer should have a copy of the EPA How to Comply manual.

Key Elements of the Worker Protection Standard

The following is a brief summary of the major elements of the WPS. Each of these categories is described in greater detail in the EPA How to Comply manual. Producers should refer to the How to Comply manual for complete details and explanations of the requirements of the WPS.

Information and Education. To ensure employees will be informed about exposure to pesticides, the WPS requires:

  • Annual pesticide safety training for workers and handlers
  • Pesticide safety poster to be displayed for workers and handlers
  • Access to labels and material safety data sheets for pesticide handlers and early-entry workers
  • Access to specific information in a centrally located Application List of pesticide treatments on the establishment

Protection. To ensure employees will be protected from exposures to pesticides, the WPS requires employers to:

  • Prohibit handlers from applying a pesticide in a way that will expose workers or other persons
  • Exclude workers from areas being treated with pesticides
  • Exclude workers from areas that remain under a restricted entry interval (REI) with narrow exceptions
  • Protect early-entry workers who are doing permitted tasks in treated areas during an REI. Requirements include special instructions and duties related to correct use of Personal Protective Equipment (PPE)
  • Notify workers about treated areas so they can avoid inadvertent exposures
  • Protect handlers during handling tasks. Requirements include monitoring while handling highly toxic pesticides and duties related to correct use of PPE.

Mitigation. To mitigate exposures that employees receive, the WPS requires:

  • Decontamination sites that provide handlers and workers an ample supply of water, soap, and towels for routine washing and emergency decontamination
  • Emergency assistance that provides transportation to a medical care facility if an agricultural worker or handler may have been poisoned or injured by a pesticide and providing information about the pesticide(s) to which the person may have been exposed.

Agricultural Owner Exemptions. Even if you are the owner of the farm, forest, nursery, or greenhouse and you or members of your family do all the work there, you are a "WPS employer". You must comply with SOME of the WPS requirements, such as adhering to REIs, PPE, and ALL the specific requirements listed in the pesticide labeling.

If you hire commercial handlers, certain information must be given from you (the operator) to the commercial handler employer.

  • Specific location and description of any areas that may be treated with a pesticide or be under an REI while handler is there, or that the commercial handlers may be in (or walk within 1/4 mile of),
  • Restrictions on entering those areas.

Crop Advisors. The WPS requires employers to provide certain protections to their employees who are working as crop advisors. Examples of crop advisors are crop consultants, scouts, and integrated pest management monitors. An independent or commercial crop advisor is any person working as a crop advisor who is employed (including self-employed) by anyone other than the agricultural establishment on which the work is being done. Certain provisions of the WPS apply to crop advisors depending on when the advisor is on the farm and when the pesticide has been applied.

Commercial Handlers. Employers of commercial handlers must make sure that their customer (the operator of the farm, forest, nursery or greenhouse) knows certain information such as: specific location and description of the area treated with the pesticide, time and date pesticide is to be applied, product name, EPA registration number, active ingredient(s), REI for the pesticide, whether the labeling requires treated area posting, and oral notification and any other specific requirements on the pesticide labeling concerning protection of workers and other persons during or after application.

For more information on the WPS, contact your Cooperative Extension Pesticide Safety Education Coordinator, State Lead Agency, or EPA Region 1 office, or visit https://www.epa.gov/pesticide-worker-safety/agricultural-worker-protection-standard-wps.

Pesticides and The Endangered Species Act

The following description has been endorsed by the Weed Science Society of America, Entomological Society of America, and American Phytopathological Society.

1. What is the Endangered Species Act (ESA)?

The Endangered Species Act is a long-standing federal law, first passed in 1973, which requires government agencies to ensure any actions they take do not jeopardize a species that has been federally listed as endangered or threatened. When an agency has a proposed action that might affect a listed species or its habitat, they consult with one or both of the agencies that helps enforce the ESA, the U.S. Fish and Wildlife Services or the National Marine Fisheries Service (this is known as “a consultation” with “the Services''). The Services then may recommend changes to the project or action to protect listed species or habitats.

2. How does the ESA affect pesticide use?

The Environmental Protection Agency (EPA) Office of Pesticide Programs (OPP) is the federal agency that regulates pesticide use. Because the use of pesticides can affect animals and plants or their habitat, pesticide registrations are considered “actions” that would trigger an endangered species consultation.

3. Why am I hearing about the ESA and pesticide use now?

Due to the complex nature of the process, the EPA has not fully completed the required endangered species consultations with the Services for pesticide registrations in the past, which has left many of those pesticides vulnerable to lawsuits. Courts have annulled pesticide registrations which has led to their removal from market. To make pesticide registrations more secure from litigation, ultimately all pesticide registrations will comply with the Endangered Species Act.

4. How will this affect the pesticides I use today?

Many pesticide labels will likely have changes that could include:

  • Requirement to check the EPA's Bulletins Live! Two website and follow current ESA restrictions for the pesticide product in the bulletin
  • Measures to reduce spray drift
  • Measures to reduce runoff/erosion
  • Other measures to reduce pesticide exposure to listed species and their habitat

In short, farmers and applicators should expect to see some new application requirements on their pesticide labels. But there is no need to panic. To date, no pesticide has ever been fully removed from the market based solely on endangered species risks, and that remains an unlikely scenario in the future.

5. Why does complying with the ESA matter?

By starting to fully comply with the ESA, EPA anticipates that this will give farmers and applicators more stable, reliable access to the pesticides they need. Furthermore, the ESA has been successful at bringing back some species Americans care about—such as the bald eagle and the Eggert sunflower—and restoring them to healthy populations, which has benefited the natural and cultivated ecosystems that agriculture and society rely on.

Pesticide Storage

Pesticides should always be stored in their original containers and kept tightly closed. For the protection of others, especially firefighters, the storage area should be posted as Pesticide Storage and kept securely locked.

Herbicides, especially hormone-like weed killers such as 2,4-D, should not be stored with other pesticides (primarily insecticides and fungicides) as they can volatize and be absorbed by other pesticides.

Store pesticides in a cool (40-80ºF), dry, well-ventilated area that is not accessible to children and others who do not know or understand the safe and proper use of pesticides.

Any restricted-use pesticide or container contaminated by restricted-use pesticides must be stored in a secure, locked enclosure while unattended. That enclosure must bear a "pesticide storage" warning sign readable at a distance of 20'. If any pesticide has to be stored in other than its original container, that container must be labeled with the name and concentration of the active ingredient and the signal word and warning statements for the pesticide along with a copy of the label. Keep an inventory of all pesticides stored in an area away from the storage site, so that it may be referred to in case of an emergency at the storage site.

Make available to personnel at all times: a respirator with chemical cartridge, gas mask with canister, goggles, rubber gloves and aprons, fire extinguisher, and a detoxicant for spilled materials suggested by your local fire department. Instruct all personnel on proper use of the above equipment and on what to do in case of emergency. A shower stall with plenty of soap should be made available on the premises. Prompt washing in case of accidental spillage may be a matter of life and death.

Keep your local fire department informed of the location of all pesticide storage areas. Fighting a fire that includes smoke from burning pesticides can be extremely hazardous. Firefighters should be cautioned to avoid breathing any smoke from such a fire. A fire with smoke from burning pesticides may endanger people in the immediate area or community. They may have to be evacuated if the smoke from a pesticide fire drifts in their direction.

Winter Storage of Pesticides. Plan pesticide purchases so that supplies are used by the end of the growing season. When pesticides are stored for the winter, keep them at temperatures above freezing, under dry conditions, and out of direct sunlight. The following points should be observed:

  • Read the label. Special storage recommendations or restrictions will be printed on the label.
  • Write the purchase or delivery date of the product on the label with waterproof ink. Products may lose their effectiveness over several years.
  • Ventilation is important for storage of most pesticides.
  • Store herbicides separately from other pesticides to avoid cross contamination. Below are signs of quality deterioration:

FORMULATION

GENERAL SIGNS OF DETERIORATION

EC 

Evidence of separation of components such as sludge or sediment. Milky appearance does not occur when water is added. 

Oils

Milky appearance does not occur when water is added. 

WP, SP 

Excessive lumping; powder does not suspend in water. 

D, G

Excessive lumping or caking 

 

After freezing, place pesticides in warm storage (50-80ºF, or 10-26.7ºC). Shake or roll container every few hours to mix product or eliminate layering. If layering persists or if all crystals do not completely dissolve, do not use product. If in doubt, call the manufacturer.

Emergency Information

Human Exposure. If someone has swallowed or inhaled a pesticide or gotten it in the eye or on the skin:

  • Call 911 if the person is unconscious, having trouble breathing, or having convulsions.
  • Check the label for directions on how to give first aid.
  • Call the Poison Control Center at 1-(800)-222-1222 for help with first aid information.

The National Pesticide Information Center (NPIC) 1-800-858-7378 (http://npic.orst.edu/) can also provide information about pesticide products and their toxicity.

Poisoning Information (Adapted from Ohio Vegetable Production Guide). Make sure your doctor has a copy of the Note to Physicians that is placed on the labels of dangerous pesticides.

Treatment for pesticide poisoning is very precise. The antidotes can vary for the different pesticides. In an emergency, call your doctor and provide specific information on the trade name and common name of the pesticide exposed to. Your doctor will then consult the center if necessary.

Tables 26, 27, and 29 list restricted-use fungicides, insecticides, and herbicides that are commonly recommended for vegetable disease, insect, and weed control along with their oral and dermal LD50 values. Materials with an LD50 value of less than 100 should be considered highly toxic and handled with extreme caution.

Spills. The National Response Center can help you decide how to respond to a spill. They can be reached at: 1-(800)-424-8802. In addition, CHEMTREC maintains a large database of Safety Data Sheets, chemical information references, resources, and networks of chemical and hazardous material experts. CHEMTREC provides access to technical information regarding chemical products as well as telephone access to product specialists, chemists, or other experts. (1-800-262-8200 in the U.S. or 703-741-5500 outside the U.S.)

Reporting a Spill. The National Response Center (NRC) is the sole federal point of contact for reporting oil and chemical spills. If you have a spill to report, contact NRC at 202-267-2675 or 1-800-424-8802 (toll-free) or visit https://www.epa.gov/emergency-response/national-response-center for additional information on reporting requirements and procedures. Producers should be aware that they may be required to report spills to their state Lead Agency or their state Department of Environmental Protection.

The Comprehensive Environmental Response, Compensations, and Liability Act (CERCLA) requires that all releases of hazardous substances (including radionuclides) exceeding reportable quantities be reported by the responsible party to the National Response Center (NRC). Title 40 of the Code of Federal Regulations Part 302 promulgates reportable quantities and reporting criteria. All the Extremely Hazardous Chemicals (EHS) that overlap with the CERCLA listed chemicals table (40 CFR Part 302.4) should be reported to NRC as well as to the LEPC and SERC.

For small pesticide spills or for more information, call the pesticide manufacturer or the National Pesticide Information Center (NPIC) at 1-800-858-7378. 

Protecting Groundwater and Surface Waters

Protecting Groundwater and Surface Waters Evonne Gong

There is considerable public concern about water quality, and agriculture is coming under increasing scrutiny regarding practices that can affect water quality. Many pesticides and fertilizers are soluble in water and can leach through the soil to contaminate underlying groundwater. Several factors affect the movement of chemicals in the soil and their likelihood of reaching groundwater. Consideration of the following factors can minimize the threat to groundwater:

  • Solubility is the ability of a chemical to dissolve in a solvent. Pesticides that are highly soluble in water are often desirable from an applicator's perspective because they are less likely to clump and/or separate.  However, they also pose potential water quality issues as they can easily leach into the groundwater supply.  If practical, to reduce leaching potential select the least soluble material and use the lowest effective rate.
  • Adsorption is the binding of a chemical to the surfaces of soil particles and organic matter. Some chemicals are tightly adsorbed and do not easily leach from soils; however, they have a higher risk of moving with soil when there is surface erosion. Others have low adsorption, and will leach more easily.
  • Persistence refers to the amount of time a chemical will stay in the environment before being broken down into nontoxic substances. The rate of breakdown is affected by sunlight, temperature, soil pH, moisture, and microbial activity. Pesticide persistence is measured in terms of half-life, which is the length of time needed for one half of the amount applied to break down. Persistent chemicals break down slowly, increasing the chance for them to leach into the soil. Conversely, short-lived materials may be degraded before significant leaching occurs. Many pesticides are broken down by sunlight (photodegradation) and/or microbial action. Incorporation of pesticides into the soil reduces or eliminates photodegradation. As depth in the soil increases, there is less microbial degradation. Any practice that slows degradation increases persistence and the likelihood of leaching. Generally, foliar-applied materials are more likely to break down before significant leaching occurs than those that are applied to the soil.

Soil Characteristics and Topography. Soil texture and organic matter greatly influence the movement of pesticides and fertilizers. Fine textured soils and those with high amounts of organic matter are highly adsorptive, whereas sandy soils low in organic matter are not. Highly permeable soils with permeable underlying layers allow for rapid downward movement of water and dissolved chemicals. Steep grades and long slopes allow water to build up speed and carry soil and contaminants off-site. Know your soils and apply chemicals accordingly.

Water Table. High water tables are especially vulnerable to contamination because little time is required for chemicals to reach groundwater. Tile drainage allows contaminants to leave the field faster and enter surface waters directly through outlet pipes. Excessive precipitation or irrigation, or poorly timed irrigation, immediately after pesticide or fertilizer applications, can also move contaminants off-site and into surface and ground water quickly.

Contact Cooperative Extension and the Natural Resource Conservation Service about questions you may have regarding the use of certain pesticides on your soils.

Leachable Pesticides. The following are some pesticides used on vegetables that have been identified as having high leaching potential:

  • alachlor (Lasso)
  • atrazine (Aatrex)
  • bentazon (Basagran)
  • chlorothalonil (Bravo)
  • DCPA (Dacthal)
  • methomyl (Lannate)
  • metolachlor (Dual)
  • metribuzin (Sencor/Lexone)
  • simazine (Princep)

Pesticide Mixing & Application

Pesticide Mixing & Application Evonne Gong

Formulations

Pesticide products are formulated as either liquids or solids. The appropriate formulation to choose may be dependent upon several factors, including the equipment available, the cost of the product, the pest(s) to be controlled, and both user and environmental safety. The formulation of a product is often indicated by a suffix to the trade name:

  • Emulsifiable concentrates (EC) are less troublesome to spray equipment than wettable powders (WP). The water-based flowable concentrates and wettable powders are less likely to cause plant injury than oil-based concentrates of similar materials 
  • Wettable powders/suspendable powders (WP) are less likely than ECs to cause injury to sensitive plants or to cause trouble when mixed with fungicides or other pesticides.
  • Dry flowables (DF) are similar to wettable powders in their formulation but are pelletized to minimize dust. 
  • Flowables (F) are liquid formulations with similar properties to latex paint. Clean equipment immediately after use.

When tank-mixing pesticides, mix in the proper order. The order is: Wettable Powders (WP), Water Dispersible Granules (WDG), Flowables (F) (DF) (SC), Water-dispersible liquids (AS), Emulsifiable Concentrates (EC), and Solutions (S). Always follow the pesticide label when using adjuvants such as spreader stickers, surfactants, etc.

Adjuvants

Adjuvants are non-pesticide chemicals that are added to pesticides or to pesticide spray mixtures to improve their chemical or physical characteristics. The most common types of adjuvants are nonionic surfactants, crop oil concentrates, spreader/stickers, drift control agents, buffering agents, compatibility agents and foam-reducing agents. Adjuvants can reduce or eliminate many spray application problems by performing specific functions. These functions include spreading, wetting, sticking, reducing drift, buffering, improving compatibility, reducing foaming, and improving the effectiveness of certain pesticides. Non-ionic surfactants are usually best for improving mixing of pesticides, for enhancing coverage of leaf surfaces, and for improving retention of the pesticide on the crop or weed. Although several adjuvants perform more than one function, no one adjuvant can perform all of these functions.

The most important source of information you have to determine whether or not to use an adjuvant is the pesticide label. Some prohibit the use of adjuvants due to the potential for severe crop injury or loss. Surfactants can increase the potential for crop injury by enhancing penetration of pesticides into the foliage or by causing burning on their own. High temperature and humidity enhance this potential injury. Avoid spraying in the mornings or middle of days when you can add the temperature (ºF) and % humidity together and get 150 or more.

It is best to avoid silicone-based surfactants, ionic surfactants, or others that you are not familiar with unless you have a specific purpose for using them. If a label does not list a certain tank mix that you want to use AND, at the same time, does not preclude it, you may make the tank mix. Remember, however, that you should try it on a small scale first to make sure that there will be no problems.

Some labels provide no mention of adjuvants; in this case, consult the manufacturer or pesticide dealer.

Know Your Water

The pH of the water in your tank mix can sometimes affect the efficacy of pesticides. Insecticides, in particular, tend to break down (hydrolize) rapidly in alkaline water. Water pH can vary, depending on the source, from 5.0-9.5. Neutral water has a pH of 7.0, while alkaline water is higher than 7.0. If your water pH is much higher than 8.0, you may want to consider using an acidifying agent such as vinegar to lower the pH in the tank. Many of the pH-sensitive pesticides have acidifying agents in the formulation that moderate the effect of alkaline water. However, growers who suspect a pH problem should have their water tested. This can be done on the farm with pH test kits. Also, organic matter can tie up certain pesticides or clog nozzles, so be sure to use water that is free of organic debris.

Selection of Sprayer Tips

The selection of proper sprayer tips for use with various pesticides is very important. Nozzle tips must be selected according to the spray coverage, droplet size, and application volume desired. Flat fan spray tips are designed for preemergence and postemergence application of herbicides. These nozzles produce a tapered-edge spray pattern that overlaps for uniform coverage when properly mounted on a boom. Standard flat fan spray tips are designed to operate at low pressures (30-60 psi) to produce small- to medium-sized droplets that do not have excessive drift. Flood-type nozzle tips are generally used for complete fertilizer, liquid N, etc., and sometimes for spraying herbicides onto the soil surface prior to incorporation. 

Full and hollow cone nozzles deliver circular spray patterns and are used for application of insecticides or fungicides to crops where thorough coverage of the leaf surfaces is extremely important and where spray drift will not result in crop injury of nearby plants. They are used when higher water volumes and spray pressures are recommended. With cone nozzles, the disk size and the number of holes in the whirl plate affect the output rate. Various combinations of disks and whirl plates can be used to achieve the desired spray coverage.

Pesticide Equipment Calibration

Pesticide Equipment Calibration ghiggins

Calibration is the process of measuring and adjusting the amount of pesticide your equipment will apply over a target area. Periodic calibrations of sprayers, dusters, and granule distributors are necessary to ensure accurate delivery rates of pesticides per acre. Calibrations are made by measuring the total gallons of water applied per acre, in the case of sprayers, and the total pounds of dust or granules applied per acre, in the case of dust and granule distributors. Too little spray or dust applied results in inadequate distribution of toxicant over plant surfaces. Control is usually poor, and additional applications are required. Too much per acre is hazardous for the applicator, is frequently injurious to plants (phytotoxic), and could lead to excessive residues if applied close to harvest.

Sprayer Calibration

Boom Sprayers

Before Calibrating:

  • Thoroughly clean all nozzles, screens, etc., to ensure proper operation.
  • Check to be sure that all nozzles are the same, are made by one manufacturer, and have the same part number.
  • Check sprayer discharge and calculate gallons per minute. Run the sprayer at a certain pressure and catch the discharge from each nozzle for a known length of time. Check the spray patterns of all nozzles for uniformity and replace nozzles that do not have uniform patterns or do not fill containers at the same rate. If there is more than 10% variation between any nozzles, all the tips should be replaced. Collect all the discharge, measure the total volume and convert the volume to gallons. Divide this volume by the time in minutes to determine discharge in gallons per minute. When it is not convenient to catch the discharge from each nozzle, a trough may be used to catch the total discharge.
  • Select an operating speed. Note the tachometer reading or mark the throttle setting. When spraying, be sure to use the same speed as used for calibrating. Careful control of ground speed is very important for accurate spray application. Select a gear and throttle setting to maintain constant speed. A speed of 2-3 miles per hour is desirable. From a "running start," mark off the beginning and ending of a 30-second run. The distance traveled in this 30-second period divided by 44 will equal the speed in miles per hour. Example: At a tractor speed of 1 mile per hour, you would travel 88 feet in 1 minute, 44 feet in 30 seconds or 500 feet in 5 minutes and 41 seconds.
  • Select an operating pressure. Adjust pressure to desired psi according to the nozzle manufacturer. Do this while pump is operating at normal speed and water is actually flowing through the nozzles. This pressure should be the same during calibration and field spraying.

Calibration Using the Jar Method:

  1. Measure a course on the same type of surface (sod, plowed, etc.) and same type of terrain (hilly, level, etc.) as that to be sprayed, according to nozzle spacing as shown in the table below. This distance is equivalent to 1/128th of an acre.
    Nozzle Spacing (in.) 16 20 24 28 32 36 40
    Course Length (ft.) 255 204 170 146 127 113 102
  2. Time the seconds it takes the sprayer to cover the measured distance at the desired speed in the same field conditions that you are spraying. Average several runs. This is the time required to cover 1/128 acre.
  3. With the sprayer standing still, operate at selected pressure and pump speed/engine RPM. Catch the water from each nozzle for the number of seconds measured in step 3. Any 1-quart or larger container, such as a mason jar or measuring cup, if calibrated in fluid ounces, can be used. You can also use a specially designed calibration jar; if you buy one, follow the manufacturer’s instructions. Make accurate speed and pressure readings and jar measurements. Make several checks. Keep in mind that you are collecting less than a quart of liquid to measure an application rate of several gallons per acre for many acres.
  4. Determine the average output per nozzle in ounces. If the output from any particular nozzle is more than 5% higher or lower than the average, check for clogs, clean the nozzle (with compressed air!), or replace the nozzle. Replace all nozzles if the average output is more than 15% more than a new nozzle’s output (from the manufacturer’s chart or discharge test). Repeat steps 4 and 5 after cleaning or replacing any nozzles. The average  ounces of output per nozzle equals the application rate in gallons per acre. For example, 1 oz output = 1 gallon per acre.

Calibration Using the Tank-Fill Method:

  1. Fill sprayer with water.
  2. Spray a measured area (width of area covered x distance traveled) at constant speed and pressure selected from manufacturer's information.
  3. Measure amount of water necessary to refill tank (gallons used).
  4. Multiply gallons used by 43,560 and divide by the number of square feet in area sprayed. This gives gallons per acre.
  5. Add correct amount of spray material to tank to give the recommended rate per acre.

EXAMPLE:
Assume:

  • 10 gal of water used to spray an area 660 ft long and 20 ft wide
  • Tank size - 100 gal
  • Spray material - 2 lb formulated product/A

Calculation:
      gal used x 43,560       =       10 x 43,560       =        33 gal/A
          area sprayed                        660x 20                      
 
       tank capacity             =        100 (tank size)   =        3.03 acres sprayed
           gal/A                                             33                                  per tank
 
       3.03 x 2 (lb/A) = 6.06 lb material per tank

Backpack Sprayers

Growers with diverse crops and small plantings often need to be able to apply pesticide to beds or plots of several hundred square feet. It is important to use the correct amount of pesticide in your backpack sprayer when spraying a small area, to mix and spray safely, and to follow the label instructions.

All measuring and mixing utensils used with pesticides or other chemicals should be clearly labeled with warnings that they are only to be used for measuring and mixing pesticides. Measuring equipment should be locked in the pesticide storage area. All equipment calibration should be done on the same surface to which the pesticide will be applied and at the same speed, pressure, etc.

Maintaining constant pressure can be difficult with sprayers that depend on continual hand pumping. To help with backpack sprayer calibration and application, constant flow nozzles are available. G.A.T.E. LLC manufactures a CF Valve that delivers a constant 14.9 psi recommended for spraying herbicides and a 21 psi for insecticides and fungicides. These are designed to deliver the same pressure and flow rate no matter what the pressure in the tank is above the designated pressure and shut off if the pressure in the tank falls below the designated pressure. SOLO makes a "pressure limiting valve" that actually has three settings of 5, 10 and 15 psi for their backpack sprayers that does the same thing.

Calibration will vary with the crop, crop stage, amount of canopy, and location of target pest in the crop. Seedlings will require far less material than a fully grown canopy. Match the amount of pesticide to the amount of water needed to spray the crop area at the target crop stage.

For products with rates listed in amount/acre:

  1. Calculate what portion of an acre is being sprayed. Determine sq ft of area to be sprayed (multiply bed or canopy width by row length by number of rows). Calculate what proportion of an acre this is (it may be a small fraction of an acre):

    Proportion of acre to be sprayed ÷ 43,560 sq ft per acre = number of sq ft to spray
     
  2. Calculate how much pesticide to use. Multiply the label rate per acre for the crop and pest times the proportion of an acre to be sprayed.

    Amount of pesticide needed =  amount per acre x proportion of acre to be sprayed
  1. Measure water needed per sq ft of crop. Add a known amount of water (e.g., 1 or 2 gallons) to the tank. Spray the water as if you were actually spraying your field. Remember, you must maintain constant pressure, constant walking speed, and consistent nozzle height and boom setup or wand motion to achieve the coverage you need. This amount will change with different crops and size of crop canopy. When the water is gone, stop and mark the spot. Measure the area you sprayed and calculate sq ft (length of swath x width). Calculate how many gallons (or fluid ounces, for smaller areas) are needed per sq ft.

    Gallon per sq ft = number of gallons used ÷ number of sq ft sprayed

    This can also be calculated by timing how long it takes to spray a known area, then collecting the output for the same amount of time, at the same pressure. Divide the amount used by the area sprayed.
     
  2. Determine total water needed:

    Gallons of water needed  =  gal per sq ft x number of sq ft to be sprayed
     
  3. Mix the required amount of pesticide in required amount of water. Most commonly, it is best to add half the water, add the pesticide, agitate, then add the remaining water. Spray, using the walking speed, pressure, nozzle and boom setup or wand motion that you used for calibrating.

For Products That Give Rates for Backpack Sprayers. Some pesticide labels provide a rate of product to use per gallon, for backpack sprayers or smaller areas. If this is given, it is still important to calibrate to determine the amount of water used per unit area (sq ft). Add the labeled rate pesticide per gallon of water, adjusting the rate to match the fraction or number of gallons that will be used.

Calibration for Granular Applications

The application equipment for granular fertilizer, herbicides, insecticides, etc. in many cases was not designed as precision equipment; therefore, extra care must be taken in calibration to get the results desired. Application rates of granular application equipment are affected by several factors: gate openings or settings, ground speed of the applicator, shape and size of granular material, and roughness of the ground. It takes a conscientious operator, effort, knowledge of equipment, and calibration to achieve accurate application rates. The first step to good application is to be sure the equipment is prepared for operation. Be sure all controls are free and work properly. Check and lubricate moving parts as necessary, remove corrosion, and tighten loose nuts and bolts.

Broadcast Applicators (Gravity-Drop or Spinner Applicators)

  1. From the label, determine the application rate.
  2. From the operators manual, set dial or feed gate to apply desired rate.
  3. On a level surface, fill hopper to a given level and mark this level.
  4. Measure test area. Length of run will depend on size of equipment. It need not be one long run but can be multiple runs at shorter distances.
  5. Apply material to measured area, operating at the speed applicator will travel during application.
  6. Weigh amount of material required to refill hopper to the marked level.
  7. Determine application rate:

                                                 number    x        length of      X       width of
      Area covered      =               of runs                 run (ft)             application (ft)
           (acres)                                                       43,560

     Application    =       amount applied (pounds to refill hopper)   
        rate (lb/A)                          area covered (acres)  
                           

  • NOTE: Width of application is width of the spreader for drop or gravity spreaders. For spinner applicators, it is the working width (distance between runs). Check operator's manual for recommendations, generally one-half to three fourths of overall width spread.

EXAMPLE:
Assume:

  • 50 lb/A rate
  • Test run-200 ft
  • Four runs made
  • Application width-12 ft
  • 11.5 lb to refill hopper

      Area covered    =  4 x 200 x 12     =     0.22A
                                      43,560

      Application rate =      11.5              =     52.27 lb/A
                                            0.22

  1. If application rate is not correct, adjust feed gate opening and recheck.

Band Applicators

  1. From the label, determine application rate.
  2. From the operator's manual, determine applicator setting and adjust accordingly.
  3. Fill hopper half full.
  4. Operate applicator until all units are feeding.
  5. Stop applicator; remove feed tubes at hopper.
  6. Attach paper or plastic bag over hopper openings.
  7. Operate applicator over measured distance at the speed equipment will be operated.
  8. Weigh and record amount delivered from each hopper. (Be sure all hoppers and all tubes deliver the same amount.)
  9. Calculate application rate:
  • Area covered in bands (acres) =    number           length of                band
                                                                of bands    x      run (ft)       x       width (ft)
                                                                                             43,560
  • Application rate: Rate applied in bands (lb/A)   =  total amount collected (lb)
                                                                                            area covered in bands (acres)
  1. If not correct, readjust and recheck.

Calibration for Changing from Broadcast to Band Application. Within a field, the treated area may be only a fraction of the total land area. Calculate application rates for portion of the field that is treated, using the ratio of band width to row spacing, as follows:

   Band width               broadcast                 amount needed
     in inches         x          rate                =               per acre                              
   row spacing              per acre                             of field
      in inches

Biorational and Organic Pesticides

Biorational and Organic Pesticides Evonne Gong

Pesticides vary in their toxicity to people and to non-target organisms, and in their potential ecological impact. Pest control materials that are relatively non-toxic to people with few environmental side-effects are called “biorational” pesticides in this guide. Biorational pesticides mostly include the following categories further defined in this section: biopesticide, organic pesticide, minimum-risk pesticide, and biological control. Federal law governs pesticide registration through the EPA, and materials derived from living things are defined as “biopesticides”. Organic production is regulated through the USDA National Organic Program which defines what inputs are allowed for pest management. “Organic” and “biopesticide” are partially overlapping categories, and each is defined by specific criteria that are unique. “Minimum risk pesticide” is another category that is defined by EPA; these are exempt from federal registration. “Biological control” describes living organisms that suppress pests. Some biological controls are naturally occurring, some are insects purchased by farmers for pest control, and some are microbes formulated for sale as biopesticides.

All tables in this section include products that are registered as pesticides as well as some that are exempt from EPA registration. None are federally restricted-use products. Most have high dermal and oral LD50 values (and therefore lower toxicity) and they carry the minimum EPA signal word of “Caution”. However, some organic pesticides such as copper sulfate have a low dermal and oral LD50 value and carry the EPA signal word “Danger” on their label.

Types of Biorational Pesticides

Botanicals are plant-derived materials such as pyrethrin, azadiractin, and extracts of plants such as Chenopodium ambrosioides and Swinglea glutinosa. Plant-derived oils such as neem oil, canola oil, and sesame oil are also included in this group. Botanicals are generally short-lived in the environment, as they are broken down rapidly in the presence of light and air. Products generally have low mammalian toxicity and a broad spectrum of activity. Many botanicals are considered minimum risk pesticides and are exempt from registration by EPA (see below).

Microbial pesticides are formulated from living microorganisms and/or their by-products. Microbial insecticides tend to be selective, so specific pests may be controlled with little or no effect on non-target organisms, while most microbial disease control products have a wider spectrum of activity. Microbial insecticides may be derived from bacteria (e.g. Bacillus thuringiensis, spinetoram and spinosad, Chromobacterium subtsugae), virus (e.g. nuclear polyhedrosis virus of corn earworm) or fungi (e.g. Beauvaria bassiana). Microbial disease control products are living organisms, including beneficial fungi and bacteria. Examples of microbial disease control organisms are the fungus Trichoderma harzianum and the bacterium Bacillus subtilis. While these active ingredients are generally approved for organic production (OMRI-listed) because of their natural origin, certain formulated products are prohibited because the inert ingredients or procedures used in making the product are prohibited.

Minerals. Some pesticides made from minerals, mined from the earth and minimally processed, are allowed in organic production. Kaolin clay, copper hydroxide, and iron phosphate are examples (see Table 22 and Table 24).

Synthetics. Minerals and other natural materials that are heated, chemically reacted, or mixed with surfactants may be considered synthetics. Synthetics also include insect growth regulators (IGR), which interrupt or inhibit the life cycle of a pest. They may also work by strengthening plant defenses. The National Organic Standards allow the use of some synthetics.

Biopesticides

Biopesticides, as defined by EPA, are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals. As of August 2020, there are 390 registered biopesticide active ingredients. EPA generally requires less data to register a biopesticide than to register a conventional pesticide, thus the registration process is faster. Categories of biopesticides include:

  • Microbial pesticides, in which a microorganism (e.g., a bacterium, fungus, virus, or protozoan) is the active ingredient
  • Plant-Incorporated Protectants (PIPs), in which pesticidal substances are produced by crop plants as a result of genetic material being added to the plant (e.g., Bt insecticidal protein). With PIPs, the toxin and its genetic material, but not the plant itself, are regulated by EPA.
  • Biochemical pesticides, which are naturally occurring substances that control pests by non-toxic mechanisms, such as sex pheromones that interfere with mating and scented plant extracts that attract insect pests to traps. 

Biopesticides generally fit well into an integrated pest management (IPM) strategy, which relies on monitoring for early detection of pests and emphasizes the use of selective products that protect crops while minimizing negative effects on water, air and soil, and on pollinators and beneficial insects. The purpose of this section is to bring these types of products together to help growers make decisions about pesticides and biological controls to use on their farm.

Pesticides in Organic Production

The USDA National Organic Program (NOP) allows application of biological, botanical, or mineral inputs, when cultural practices are insufficient to prevent or control crop pests, weeds, and diseases. Most of these are non-synthetic and/or minimally processed.

NOTE: not all biopesticides are labeled for use in certified organic agriculture. The grower is responsible for determining whether materials are allowed under organic standards. Sometimes this may be a challenge because some materials labeled as organic by the manufacturer may not actually be allowed by the USDA NOP. The Organic Materials Review Institute (OMRI) is recognized by the NOP as an organic material review organization. It lists products it finds suitable for certified organic production. These products are generally allowed without restriction, but some are regulated and subject to restrictions. In some cases, OMRI notes that certain formulations of a product are permitted and others are not. The list of substances approved by OMRI is subject to change.

Be sure to check with your certifier in advance to be certain that the materials and practices you plan to use are approved by your certifier, and that you understand any restrictions on use. For the most up-to-date OMRI list, visit the OMRI website at: www.omri.org. When mentioned in tables or in crop chapters, this guide designates approved organic materials with a superscript OG ( OG ), which means they were "OMRI-listed" at the time of review (June 2024).

Minimum risk (exempt) pesticides. These are a special class of pesticides that are not subject to federal registration requirements because their ingredients, both active and inert, are demonstrably safe for the intended use. This exemption falls under section 25(b) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Of the New England states, CT, ME, NH, RI and VT all require state registrations for these products while MA allows exemption for all products that meet the minimum risk criteria and are on the federal 25(b) list. For more information, please contact your state's pesticide registration office (see Pesticide Safety). The list of 25(b) exempt materials includes the following: corn gluten meal; sodium chloride; corn, linseed, sesame, soybean, and cottonseed oil; garlic and garlic oil; and essential oils including rosemary, mint, thyme, geranium, lemongrass, cinnamon, and rosemary. Some pest control products listed in this guide meet the criteria for exemption and do not have EPA pesticide registration or a pesticide label. More on this class of pesticides can be found at: https://www.epa.gov/minimum-risk-pesticides.

Biological Insect Control

Biological control is taking place in vegetable crops all the time, because native and naturalized populations of natural enemies overwinter on the farm and move into crops to feed on or lay their eggs into pest insects. Predators consume several insects over the course of their development. Parasitoids lay eggs in their host insect, which hatch into larvae that feed and develop internally and kill the host. Pathogens invade the body of the host insect. The impact of beneficial insects is often underestimated because it is easy to overlook and difficult to measure. Beneficial insects may be killed by broad-spectrum insecticides, and pest outbreaks can occur as a result. Conservation of beneficials by use of selective insecticides when pests exceed threshold levels is recommended wherever practical.

The release of commercially produced beneficials can also aid in suppressing pests. These tend to be more successful in greenhouses than in the field, but there are several instances where releases in the field have been proven to suppress or completely control key pests. Trichogramma is a genus of tiny wasps that lay their eggs inside the eggs of insects; wasp larvae develop inside, killing the egg. Several species are commercially available, but the most useful in vegetable crops are T. pretiosum for caterpillar eggs and T. ostriniae for European corn borer in sweet corn and pepper. Releases should be timed to coincide with egg laying. See Table 23 for information about biological controls for the field, and also Table 19 Biological Control for Insects and Mites in the Vegetable Transplants section.

Biological Disease Control

Biological disease control products (fungicides, bactericides, and nematicides) fall into the same classes as biological insecticides. Botanicals, minerals, and synthetics are listed in Table 24. Sulfur, potassium bicarbonate, phosphites, and copper compounds are examples of minerals or synthetics that can control fungal and bacterial diseases. Not all of these products are OMRI-listed; be sure to check with your state certifying authority for more information on these materials. Botanicals such as rosemary oil, soybean oil, or garlic extracts also appear in Table 24 and are generally OMRI-listed. Products listed in Table 24 require thorough coverage, application at the first signs of disease, and frequently repeated dosages to be effective. For products that may be used in vegetable transplant production, see Table 20.

Microbial products are listed in Table 25 and are all living organisms which require specialized storage and application procedures. Table 25 includes beneficial fungi and bacteria such as Streptomyces, Gliocladium, and Trichoderma, which compete with plant pathogens, produce toxic metabolites, or actively parasitize pathogens. Their effectiveness in university research trials has been inconsistent because of variations in environmental conditions and disease pressure. Microbial disease control products perform best in a greenhouse environment where they can establish and flourish. Control of plant pathogenic organisms on the phylloplane (leaf surface) is especially problematic, as the competing organisms can fail to establish themselves due to desiccation and exposure to sunlight. These materials have a limited shelf life, must be protected from temperature extremes, and correctly applied (plenty of water and under the correct environmental conditions) to be effective.

Biorational and Selective Insecticides and Miticides (Table 22)

Biorational and Selective Insecticides and Miticides (Table 22) Evonne Gong

This table includes products that are registered as pesticides as well as some that are exempt from EPA registration. Most have low toxicity to bees and beneficial insects. None are federally restricted-use products. Most have dermal and oral LD50 values over 2,000 mg/kg (see Tables 26 and 27 for LD50 values for insecticides and fungicides). Selective insecticides have efficacy on specific insect groups, or a specific life stage, and are therefore safe for non-target beneficial insects.

The symbol OG indicates a pesticide that has been listed by the Organic Materials Review Institute (OMRI) as compliant with the National Organic Standards and therefore approved for use in organic production.

ACTIVE INGREDIENTS TRADE NAME(S) TARGET PESTS COMMENTS
azadiractin Amazin Plus 1.2%MEOG; Aza-DirectOG; AzaGuardOG; Azatin OOG; XL; Azatrol ECOG; AzeraOG(M); Ecozin Plus 1.2%MEOG; Molt-XOG; Neemix 4.5OG; Ornazin 3%EC Aphids, caterpillars, leafhoppers, leafminers, thrips, whiteflies, beetles, and other insects An insect growth regulator extracted from the seeds of the neem tree. Works by contact or ingestion against immature stages, and has antifeedant properties.
Bacillus thuringiensis subsp. aizawai

XentariOG

Caterpillars, as listed for Bt kurstaki, as well as cross-striped cabbageworm, armyworms, cutworm

Use in rotation with Bt kurstaki products to prevent resistance. May be used in greenhouse or field.
Bacillus thuringiensis subsp. israelensis Gnatrol WDGOG Fungus gnats For use in greenhouse.
Bacillus thuringiensis subsp. kurstaki CoStarOG; DeliverOG; Dipel ES, DFOG; Javelin WGOG Many caterpillars, including cabbage looper, diamondback moth, imported cabbageworm, European corn borer, hornworms Must be ingested. Apply when caterpillars are actively feeding. Safe on beneficial insects. For some species, more effective on smaller larvae.
Bacillus thuringiensis subsp. tenebrionis strain SA-10 TridentOG Colorado potato beetle For use on potato, tomato, and eggplant. Must be ingested. (Trident currently unavailable due to formulation and shipping issues)
buprofezin

Talus 70DF

Leafhoppers, mealybugs, planthoppers, whiteflies Insect growth regulator.
Burkholderia spp. (heat-killed) Strain A396 and spent fermentation media Venerate XCOG; Majestene OG Caterpillars, cutworms, aphids, mites, thrips, whiteflies Works by contact and ingestion to disrupt insect exoskeletons and interfere with molting.
capsicum oleoresin extract, garlic oil, soybean oil Captiva Caterpillars, mites, thrips, leafhoppers, whiteflies Has antifeedant, anti-egg laying, and irritant activity, and weakens cuticles of immature stages of insect and mite pests.

Chenopodium ambrosioides extract

Requiem

Aphids, whiteflies, thrips, leafminer, mites

Contact insecticide/miticide. Can be applied for ovicidal control. Start when populations are at threshold. Compatible with beneficial insects.

chlorantraniliprole Coragen Caterpillars, Colorado potato beetle, leafminers May be used as soil or transplant water treatment at planting, in drip, or as foliar. Avoid run-off in surface waters. Non-toxic to bees.
Chromobacterium subtsugae strain PRAA4-1 GrandevoOG Caterpillars, aphids, whiteflies, mites, leafhoppers, thrips A selective biological insecticide/miticide containing fermentation solids. Works as a stomach poison upon ingestion. No systemic activity. Toxic to bees exposed to direct treatment or residues on blooming crops or weeds.
clarified hydrophobic extract of neem oil Triact 70OG; TrilogyOG Primarily labeled for (but not limited to) mite control Can be used to control mites. For best results use when population levels are low to prevent build-up. Repeat applications are needed.

clove oil, thyme oil, cinnamon oil

Ecotrol G2OG

Root maggots, wireworm, cutworm, symphylans

Soil-incorporated volatile plant oils on a corn cob carrier, applied before, during, or after planting. Exempt from registration and reporting under Federal EPA standards. 

cryolite Prokil Cryolite 96 Colorado potato beetle (larvae only), cucumber beetle, flea beetle, cutworms, some caterpillars Stomach poison, must be ingested. Sodium aluminofluoride mineral, applied as spray or dust. Reapply to cover new growth. May cause extensive wear of nozzles.
cyromazine Trigard Leafminer, Colorado potato beetle An insect growth regulator.
diflubenzuron Dimilin Armyworms, pepper weevils A selective insect growth regulator that disrupts the molting process of insect larvae.
etoxazole Zeal Mites A mite growth regulator that works as an ovicide and larvicide.
flonicamid Beleaf Aphids, plant bugs, whiteflies A pyridinecarboxamide that works by contact and ingestion. Feeding stops rapidly and mortality will follow.
flupyradifurone Sivanto Aphids, leafhoppers, whiteflies, Colorado potato beetles, squash bugs A broad-spectrum insecticide in a new class of chemistries, the butenolides. Acropetally systemic, and translaminar. No toxicity to bees in lab tests.
insecticidal soap (Potassium salts of fatty acids) Des-XOG; M-PedeOG Aphids, leafminers, mites, thrips, whiteflies Works on contact. Can be phytotoxic to some crops, test on small plot. Avoid treatment when plants are stressed. May also harm some beneficials. Also active against powdery mildews.
iron phosphate Sluggo: Snail and Slug BaitOG Snails, slugs Bait which causes feeding to cease. Death occurs over 3-5 days. Exempt from tolerance and has a zero hour re-entry interval due to low toxicity to people and wildlife.
kaolin Surround WPOG Flea beetle, striped cucumber beetle, leafhopper, thrips Interferes with insects' ability to recognize their host; particles cling to cuticle. Plant leaves turn white but growth is not inhibited. Reapply after heavy rain. To avoid lumps in mixing, form a slurry, then dilute. Maintain agitation.
metaldehyde Deadline Bullets Slugs, snails A toxic bait. Not for direct application to or contamination of edible portions of the plant; to be applied as a band treatment between rows after formation of edible parts. Long-lasting; resistant to rain and watering.
methoxyfenozide Intrepid Many species of caterpillars Mimics molting hormone; causes premature molt and death.
novaluron Rimon Caterpillars, beetles, leafminers, squash bugs, thrips, whiteflies An insect growth regulator for use on immature stages.
petroleum oil (mineral, parrafinic oils) JMS Stylet Oil, Organic JMS Stylet OilOG; Suffoil XOG aphids, leafminers, beetle larvae, mites, thrips, leafhoppers, whiteflies A horticultural oil (80% petroleum oil) insecticide, miticide, and fungicide. Kills eggs, larvae, and nymphs of insects and mites and adults of soft-bodied insects through suffocation. Registered for use as a foliar spray on a variety of crops. Also labeled for certain diseases.
pymetrozine Fulfill Aphids Works by contact and ingestion, translaminar with long residual.
pyrethrin PyGanic EC5.0IIOG, EC1.4OG Asparagus beetle, blister beetle, cucumber beetle, flea beetles, Mexican bean beetle, potato leafhopper, many caterpillars, aphids, stink bugs Botanical insecticide with broad-spectrum activity. Contact toxin with rapid knockdown but short period of activity (non-persistent). Highly toxic to fish. Derived from a chrysanthemum species cultivated in Africa. Some formulations are OMRI-listed.
pyriproxyfen Esteem; Distance IGR; Knack Thrips, whiteflies shoreflies, fungus gnats Label may include greenhouse or field use. An insect growth regulator that suppresses development of embryo within the egg, immature, and pupal stages of the insect. No activity against adult insects.

rosemary oil, peppermint oil, other essential plant oils

Ecotrol PlusOG

Aphids, beetles, bugs, early stages of caterpillars, leafminers, mites, thrips

Works on contact as an insecticide and miticide. Greenhouse and field use. Thorough coverage is needed. Exempt from registration under Federal EPA standards.

soybean oil

Golden Pest Spray OilOG; Captiva

Primarily soft-bodied insects A soybean-derived horticultural oil that works as a contact insecticide, as well as a feeding and oviposition deterrent. Exempt from registration under Federal EPA standards.

spinetoram

Radiant

See spinosad, below.

A second-generation spinosyn, similar to spinosad, below.

spinosad Blackhawk; EntrustOG; Seduce Insect BaitOG; GF-120 NaturalyteOG Caterpillars, Colorado potato beetle, asparagus beetle, flea beetle, leafminers, thrips. Baits labeled for cutworms, earwigs (Seduce) or fruit flies (GF-120) Acts both as a contact and stomach toxin. Derived from soil bacterium Saccharopolyspora spinosa. Non-disruptive to most predator insect species and some parasites. Rotate with other selective biorationals to prevent resistance. 
spiromesifen Oberon Whiteflies, mites Contact insecticide and miticide.
sulfur Microthiol DisperssOG Mites Micronized wettable sulfur, also labeled as a fungicide.
tebufenozide Confirm Caterpillars Selective insect growth regulator.

Biological Controls for Insect Pests (Table 23)

Biological Controls for Insect Pests (Table 23) Evonne Gong

The products and living organisms listed in this table suppress pests of vegetable crops. Some biological controls are naturally occurring, some are insects purchased by farmers for pest control, and some are microbes formulated for sale as biopesticides. Most are exempt from EPA registration, and most are allowable for organic production.

Part 1. Established beneficial insects that live on New England farms

SCIENTIFIC NAME COMMON NAME TARGET PESTS COMMENTS
Chrysopa and Chrysoperla spp. Green lacewings Aphids, thrips, mites, whiteflies, leafhoppers, small caterpillars, insect eggs Larvae feed voraciously on many small insect pests. Common throughout the US, and available commercially.
Coleomegilla maculata Twelve-spotted ladybeetle Aphids, small caterpillars, small beetle larvae, insect eggs Native to North America. Both adults and larvae are predators. Wide range of prey and of crops and habitats. Feeds on newly hatched larvae as well as insect eggs. Also eats pollen.
Cotesia congregatus Braconid wasp Tomato hornworm Parasitic wasp that lays eggs in hornworm caterpillars.
Cotesia rubecula Braconid wasp Imported cabbageworm (ICW) Parasitic wasp that lays eggs in small ICW. Exits and spins white, oval cocoon. Introduced to New England in 1988; now well established.
Harmonia axyridis Multicolored Asian ladybeetle Aphids Adults have many variable markings. Both adults and larvae are predators. Renowned for invading homes in fall. May be a pest of grapes. Introduced to North America; widespread range.
Orius insidiosus Insidious flower bug Aphids Commonly found in corn. Small (3 mm).
Podisus maculiventris Spined soldier bug Beetle larvae, caterpillars, insect eggs, aphids Prey includes Colorado potato beetle. Both adults and nymphs are predators. Uses piercing sucking mouthparts to feed on soft-bodied insects.
Syrphidae species Syrphid fly larva (immature of hover fly) Aphids, small caterpillars Adult hover flies mimic bees and feed in flowers. Immatures are voracious aphid predators; legless, cream or brown in color, found in aphid colonies.

Part 2: Biological control organisms, released or applied to crops

SCIENTIFIC NAME COMMON NAME TARGET PESTS COMMENTS
Beauvaria bassiana Strain GHA Mycotrol ESO, Botanigard Aphids, whiteflies, thrips, Colorado potato beetle This fungus penetrates the insect cuticle, fills its body, kills it, and releases more spores. Apply in the evening and target coverage of lower leaves, as spores are inactivated by sunlight. Use preventatively based on monitoring, before pests reach high levels. Can be tank mixed with other microbials for Colorado potato beetle.

Isaria fumosorosea Apopka Strain 97 (formerly Paecilomyces fumosoroseus)

PFR-97OG, PreferalOG aphids, mites, thrips, whiteflies, leafminers, rootworms, wireworms, grubs, caterpillars A naturally occurring fungus that penetrates the cuticle of insect pests.
Metarhizium anisopliae Strain F52 Met 52EC thrips, whiteflies, mites Composed of spores of a naturally occurring entomopathogenic fungus. Spores attach to the insect and hyphae penetrate the exoskeleton, growing inside and causing death in 3-7 days. Labeled for use as a foliar spray or soil drench on field and greenhouse onions to control thrips, and on field and greenhouse celery, lettuce, spinach, peppers, and tomatoes to control thrips, whiteflies, and mites. Persistence will generally be higher when incorporated into soil, but may be effective for a few months even in foliar applications.
Pediobius faveolatus No common name Mexican bean beetle Small parasitic wasp of the Eulophid family, which attacks Mexican bean beetle larvae. Releases should be timed to coincide with egg hatch because wasps lay eggs in young larvae, which are then killed and form a pupal case, or 'mummy', from which a new adult wasp will emerge.
Steinernema and Heterorhabditis spp. Beneficial nematodes Cutworms, white grubs, wireworms, maggots, beetle larvae, soil-dwelling adult insects Very small roundworms, mass-reared for commercial use. These seek out and penetrate their host insects, multiply within the host and kill it. They are most likely to be effective against the soil-dwelling immature stages of susceptible hosts. Nematodes require moist soil conditions to survive.
Trichogramma ostriniae No common name European corn borer

Tiny parasitic wasp that oviposits in the eggs of European corn borer. Its larvae grow and pupate in the eggs, preventing borer hatch. Start release when ECB flight begins. In sweet corn, release at 30-60k per acre per week, for 2-3 weeks per block. In pepper, release 90-120k per acre per week over 4 weeks. Reproduces in season but does not overwinter. Available from IPM Laboratories, Locke, NY.

Trichogramma pretiosum No common name Caterpillar eggs May be used in brassica crops and other crops with caterpillar pests.

Biorational and Organic Disease Control Materials (Table 24)

Biorational and Organic Disease Control Materials (Table 24) Evonne Gong

The products in this table are botanical, mineral, and synthetic biorational pesticides labeled for disease control in vegetable crops. The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. 

Most of these materials are broadly labeled for vegetable crops, unless otherwise noted. As always, read the label before use and apply only to labeled crops.

Use on vegetable crops in greenhouses and high tunnels is allowed unless noted in Comments section.

ACTIVE INGREDIENT(S) TRADE NAME(S) TARGET PESTS MATERIAL TYPE/COMMENTS
acibenzolar-S-methyl Acigard 50 WG Bacterial diseases, downy mildews, rusts Synthetic. Plant defense activator. Greenhouse use in summer squash only.

basic copper sulfate

Basic Copper 53OG

Many bacterial and fungal diseases

Mineral. Not for use in greenhouse crops. Registered for use in MA only. Other non-OMRI-listed basic copper sulfate materials are registered in other NE states.

copper hydroxide Champ WGOG Anthracnose, bacterial blight, black rot, Botrytis, downy mildew, late blight, leaf spots, Phomopsis, powdery mildew Mineral
cuprous oxide Nordox 75 WGOG Anthracnose, bacterial blight, black rot, Botrytis, downy mildew, late blight, leaf spots, Phomopsis, powdery mildew Mineral. Greenhouse use in eggplant, pepper, and tomato only.
hydrogen dioxide OxiDate 2.0OG Alternaria, anthracnose, bacterial blight, Botrytis, Fusarium wilt, Phytophthora, powdery mildews, Pythium, Rhizoctonia, rusts, Sclerotinia Synthetic. Contact activity only.
kaolin Surround WPOG Powdery mildews, sunburn, and heat stress Mineral
neem oil TrilogyOG, Triact 70OG Anthracnose, Botrytis, downy mildews, leaf spots and blights, powdery mildews, rusts, scabs Botanical

oils, petroleum based

JMS Stylet-OilOG, Suffoil-XOG

Alternaria, gummy stem blight, powdery mildews, rusts

Synthetic and natural oils

potassium bicarbonate KaligreenOG, MilStopOG Alternaria, anthracnose, Botrytis, downy mildews, Fusarium, leaf spots, Phytophthora, powdery mildews Synthetic. Contact activity only.
potassium phosphite Helena ProPhyt Downy mildews, Phytophthora, Pythium Mineral. Systemic. Drench at transplant.
mono- and dibasic sodium, potassium, and ammonium phosphites Phostrol Downy mildews, Phytophthora, Pythium Synthetic. Use caution when using in a tank mix.
monopotassium phosphate Nutrol Powdery mildews Synthetic. Greenhouse use in cucurbits, tomato, and pepper only.

potassium silicate

Sil-MATRIX

Powdery mildews

Mineral

Reynoutria sachaliensis extract

RegaliaOG

Bacterial spot, speck, and canker, Botrytis, leaf spots, powdery mildews

Botanical. Plant defense activator. Use caution in tank mix.

rosemary, clove, thyme, and peppermint oils

Sporan EC

Bacterial spot, downy mildews, early blight, gray mold, late blight, powdery mildews

Botanical. Registered for use in CT only.

streptomycin sulfate

Agri-Mycin 50 Bacterial diseases Biological antibiotic. Labeled for celery, peppers, potato, and tomato only. Greenhouse use for pepper and tomato only.
sodium carbonate peroxyhydrate PerCarbOG Angular leaf spot, anthracnose, Alternaria, bacterial leaf blight, bacterial spot and speck, black rot, Botrytis, downy mildews, early blight, gummy stem blight, late blight, powdery mildews,rust, white rot Synthetic
sulfur Microthiol DisperssOG Powdery mildews, leaf spots Mineral
tea tree oil Timorex ActOG Anthracnose, Alternaria, bacterial spot, speck, and canker, Botrytis, downy mildews, gummy stem blight, leaf mold, leaf spots and blights, powdery mildews, white rot Botanical. Greenhouse use for fruiting vegetables, leafy vegetables, and cucurbits only.
thyme oil Thymox ControlOG Fungal diseases Botanical. Registered for use in MA only.

Microbial Disease Control Products (Table 25)

Microbial Disease Control Products (Table 25) Evonne Gong

The materials listed in this table are formulated from living microorganisms and/or their byproducts.

The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. 

Use on vegetable crops in greenhouses and high tunnels is allowed unless noted in Comments section.

TRADE NAME ACTIVE INGREDIENT(S) TARGET DISEASES LABELED CROPS COMMENTS
Actinovate AGOG Streptomyces lydicus strain WYEC 108 Downy mildew, powdery mildew, Botrytis, Sclerotinia spp., Pythium, Phytophthora, Fusarium, Rhizoctonia, Verticillium spp., Sclerotium  Most vegetable crops Seed and soil treatment (drench/in-furrow), foliar applications
AgriPhageOG Bacteriophage active against Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato Bacterial spot and speck Tomato and pepper only Foliar applications
AgriPhage-CMMOG Bacteriophage active against Clavibacter michiganensis subsp. michiganensis Bacterial canker Tomato only Foliar applications
AvivOG Bacillus subtilis strain IAB/BS03 Botrytis, Alternaria, downy mildews, powdery mildews, rusts, leaf spots and blights, anthracnose, gummy stem blight, Phytophthora, bacterial blight, Pythium, Fusarium Most vegetable crops Seed, in-furrow, and foliar applications
Bio-Save 10 LPOG Pseudomonas syringae Strain ESC-10 Fusarium and Helminthosporium storage rots Potato Post-harvest application. Registered for use in ME only.
Bio-TamOG

Trichoderma asperellum (ICC 012) & Trichoderma gamsii (ICC 080)

 Fusarium, Rhizoctonia, Pythium, Phytophthora, Sclerotinia, Sclerotium, Verticillium Most vegetable crops

Soil applications

 

2-3-2 Companion Liquid (WP) Biological FungicideOG

Bacillus subtilis GB03

Anthracnose, Botrytis, bacterial diseases, powdery mildew, Phytophthora, Pythium, Rhizoctonia, leaf spots and blights, Fusarium, Clubroot 

All vegetable crops

Soil treatment, hydroponics, seed treatment

CeaseOG

Bacillus subtilis QST 713 strain

Rhizoctonia, Pythium, Phytophthora, Fusarium, bacterial diseases, leaf spots and blights, powdery mildew, downy mildew, Sclerotium, and Sclerotinia

Most vegetable crops

Soil drench

 

Contans WGOG Coniothyrium minitans Strain CON/M/91-08 Sclerotinia sclerotiorum and
Sclerotinia minor
Most vegetable crops (Bayer formula NOT labeled for tomato) Soil treatment
DiTera DFOG Myrothecium verrucaria Strain AARC-0255 Nematodes Most vegetable crops Soil treatment
Double NickelOG (LC and 55) Bacillus amyloliquefaciens strain D747 Botrytis, Alternaria, fungal leaf spots and blights, powdery mildews, downy mildews, Rhizoctonia, Pythium, Fusarium, Sclerotinia, and suppression of rusts, late blight, early blight, bacterial diseases All vegetable crops For ground, aerial, and chemigation applications
MycostopOG Streptomyces sp. strain K61 Fusarium, Alternaria, Phomopsis, Botrytis, Pythium, Phytophthora, Rhizoctonia All vegetable crops Seed or soil treatment
 
ObtegoOG

Trichoderma asperellum ICC 012 & Trichoderma gamsii ICC 080

Fusarium, Phytophthora, Pythium, Rhizoctonia, Sclerotinia Cucurbits, leafy vegetables, fruiting vegetables, herbs, bulb crops Soil treatment

Prestop WPOG

Gliocladium catenulatum Strain J1446

Pythium, Phytophthora, Rhizoctonia, Fusarium, Verticillium, Botrytis

Most crops. See label for crops registered for incorporated or drench treatment only.

Foliar spray, soil treatment

RhapsodyOG Bacillus subtilis QST 713 Alternaria, bacterial blight(Xanthomonas), downy mildew, powdery mildew, Sclerotinia spp., Botrytis, rust, Pytophthora infestans Broccoli, carrot, lettuce, onion, pepper, tomato, herbs

Foliar spray or soil drench

RootShieldOG (WP and Granules) Trichoderma harzianum Rifai strain T-22 Pythium, Rhizoctonia, Fusarium, Thielaviopsis Most vegetable crops

In-furrow treatment, transplant dips, potting mix amendment

RootShield PlusOG (WP and Granules) Trichoderma harzianum Rifai strain T-22 & T. viriens strain G-41 Pythium, Rhizoctonia, Fusarium, Thielaviopsis Most vegetable crops

In-furrow treatment, transplant dips, potting mix amendment

SerenadeOG (Opti and ASO)

Bacillus subtilis strain QST 713 Alternaria, anthracnose, Botrytis, downy mildews, powdery mildews, rusts, Helminthosporium, Didymella, Phoma, bacterial diseases Most crops

Foliar spray or soil drench

SonataOG Bacillus pumilis QST 2808 Alternaria, downy mildew, powdery mildew, rust Most crops
Foliar spray or soil drench
StargusOG Bacillus amyloliquefaciens F727 Fusarium, Phytophthora, Pythium, Rhizoctonia, Sclerotinia, downy mildew, Botrytis Most crops  

Taegro 2OG

Bacillus subtilis var. amyloliquefaciens FZB24 Rhizoctonia, Fusarium, Sclerotinia, Pythium, Phytophthora, leaf spots, powdery mildews Fruiting vegetables, cucurbits, leafy vegetables, root and tuber vegetables In-furrow, transplant drench, basal spray for primarily soilborne diseases. 
TheiaOG Bacillus subtilis strain AFS032321 Leaf spots, anthracnose, black rot, bacterial spots and blights, powdery mildews, Fusarium, Phytophthora, Pythium, Rhizoctonia, downy mildews, gummy stem blight Most vegetable crops Seed treatment, soil applications, foliar sprays
Triathlon BAOG Bacillus amyloliquefaciens D747 Botrytis, Rhizoctonia, Fusarium, Sclerotinia, Pythium, Phytophthora, leaf spots, powdery mildew, downy mildew Most crops Soil and foliar applications

Disease Management

Disease Management Evonne Gong

For information on specific diseases, use the search bar or see the appropriate crop section(s).

Plant diseases can result from a combination of many factors. Under certain conditions, viruses, nematodes, bacteria, fungi, heat, cold, chemicals, and air pollution can all promote plant disease. By following practices, including those listed below, to create conditions that encourage plant vigor, losses due to disease can be minimized.

  • When diseases begin early in the season, yield and quality are more likely to be reduced. Always use disease-free seed, transplants, or cuttings.
  • Use hot water- and/or fungicide-treated seed where appropriate. Hot water treatment may prime the seeds to sprout; treatment should be done as close to planting as possible. Purchase seeds and plants from a reputable source.
  • Pasteurize seedbed soil and potting soils with steam or chemicals. Unopened bags of soilless media do not have to be treated.
  • Disinfect pots, flats, tools, and greenhouse surfaces before planting.
  • Avoid the reintroduction of disease-causing organisms to disinfected soil.
  • Practice good sanitation to avoid letting pathogens get a head start. Destroy plant debris, trash piles, and weeds that harbor pathogens. Remove and destroy infected plants and plant parts when feasible. Practice crop rotation.
  • Promote plant vigor. Do not overwater or plant in poorly drained soils. Use fertilizers, growth regulators, herbicides, insecticides, and fungicides only as directed. Measure them accurately and apply them properly to avoid toxicity to the plants and to yourself.
  • Some healthy plants can succumb to disease. Select varieties that are resistant to the diseases that you know are a problem in your area.
  • Protect plants from pathogens by following a suitable pesticide spray program. Knowing the diseases of your crop and the most effective time to begin spraying can save a crop and your money.
  • Air-blast sprayers can increase the spread of bacterial diseases.
  • Effective control of plant diseases depends upon the accurate identification of the disease. Contact your regional or state Extension specialist or plant disease clinic (see Specimens for Disease Diagnosis below).

Hot Water Treatment of Seed

Ideally, seed should be custom treated by request. If this is not possible, seed can be hot water-treated at home. Some lots of seed can be vulnerable to heat treatment. Always treat a small amount of seed (50-100) of each lot before treating the remainder of the lot. After the test treatment, air dry completely and then moisten a sample for a germination test. Include untreated seed of the same lot for comparison. Treated seed should be used in the current season. Small seeded crops such as brassicas, carrot, pepper, etc. are the most appropriate for hot water treatment. Each seed type has a corresponding temperature and length of time for treatment. Full instructions for treating seed on your own may be found here: https://ag.umass.edu/vegetable/fact-sheets/hot-water-seed-treatment. Always check with the seed source to make sure it has not already been treated.

Specimens for Disease Diagnosis

Effective control of plant disease depends upon the accurate identification of the cause. Accurate and rapid diagnosis of a plant disease by diagnostic labs requires examination of specimens that are representative of the disease, plus a review of information concerning the growing of the crop. The diagnosis and recommendations reported to growers are based on this information. Plants in advanced stages of decay or desiccation, or those that arrive with no case history information, cannot be diagnosed properly. Before sending the specimen, contact your regional or state Extension specialist or plant disease clinic. Deliver the specimen by overnight mail. Some states may charge a fee for diagnostic services. Supply as much of the following information as possible:

  • Your name, address, zip code, phone number, and e-mail address
  • Crop, cultivar, and date collected
  • Planting size (acres) or number of plants
  • Percentage of plants affected
  • Distribution of disease (general or all over field, scattered here and there, or localized in a small area of field)
  • Symptoms you are concerned about (blight, wilt, stunting, death, yellowing, leaf mottle, stem rot, root rot, fruit rot, leaf spot, die back, etc.)
  • Chemicals applied, including dates and rates of fertilizers, fungicides, nematicides, herbicides, and growth regulators
  • Any information that you believe may be important about the circumstances leading to the disease

For more information on plant diagnostic clinics in each of the New England states, see Diagnostics for Plant Problems.

Virus Diseases

Many different viruses can infect vegetable crops. Some, like papaya ringspot virus-W, have a narrow host range, while others, like cucumber mosaic virus and tomato spotted wilt virus, infect a wide variety of vegetable crops as well as ornamentals and weeds. Symptoms of viral infection are most evident on foliage and fruit. However, the symptoms are not always unique to viruses and may closely resemble nutritional disorders, herbicide injury, or insect feeding. A subtle but common symptom of viral infection is overall stunting and reduction in yield.

Viruses are spread in a variety of ways. Mechanical transmission through handling of plants or use of contaminated tools is an efficient means of spreading tobacco mosaic virus and potato virus X. Most viruses, however, are not spread in this manner. Insects such as aphids, thrips, mites, leafhoppers, and beetles provide the most important means for viruses to move from infected to healthy plants. Some viruses, such as tomato ringspot virus and squash mosaic virus, can be transmitted through infected seed. Perennial weeds and ornamental hosts provide an important reservoir for viruses to survive from one season to the next.

Aphids are the most important primary and secondary vectors of viral diseases. Depending on their relationship with the aphid, viruses are classified as either persistent or non-persistent. Intermediate forms also exist. Aphids that acquire persistent viruses do so after a minimum feeding time of 10-60 minutes. Following acquisition, a latency period of at least 12 hours must pass before the aphid can transmit the virus. The aphid remains infectious for at least a week, or in some cases, for its entire life. With non-persistent viruses, the aphid can pick up the virus rapidly (within seconds or minutes) while probing the host tissue and can transmit the virus immediately to another plant. However, the ability of the aphid to successfully transmit the virus is quickly lost (within minutes). Insecticides increase the spread of non-persistent viruses by stimulating probing activity of the aphid. Contact insecticides are generally less useful than systemics for controlling insect-vectored viruses.

In general, the spread of viruses is best controlled by cultural practices such as cultivar selection, planting date and location, weed reduction, and roguing of diseased plants. Row covers may prevent aphids from probing and feeding on plants early in the season, preventing the spread of viruses. Occasionally, seed, or transplants are infected and the problem is not apparent until well into the growing season. There are no chemical control measures for virus diseases other than those directed at the vector or weed hosts. For more specific control measures, refer to the appropriate crop disease control section.

Fungicides and Bactericides

Fungicides and bactericides are used to prevent, not cure, diseases. Applications initiated before disease appears or at the first sign of disease are the most effective way to use these pesticides. Knowledge of the cause of the disease is required to select the proper material. Your regional or state specialist can assist you in determining the cause (see Specimens for Disease Diagnosis, above). Note that the continuous use of certain bactericides or fungicides can result in pathogens becoming resistant to these chemicals.

For detailed information about fungicides and bactericides, see Table 24, Table 25, and Table 26.

Resistance Management

Pathogens that survive an application of a fungicide are likely to pass the trait that enabled them to survive on to their offspring. A single genetic change in the pathogen can render single-site mode of action (systemic) fungicides ineffective. Repeated applications of the same type of fungicide exert selection pressure on the pathogen population and eventually eliminate almost all the susceptible individuals from a pest population. Resistance can develop in a very short time.

It is necessary to practice resistance management to preserve the useful life of a fungicide. The most effective way to extend the useful life of a product is to use it once and then alternate with a fungicide with a different mode of action. Fungicides are grouped according to chemical class or site of their activity and assigned a group number by the Fungicide Resistance Action Committee (FRAC). To select fungicides with different modes of action, see FRAC group in Table 26 and in the following section, Fungicides and Bactericides Alphabetically Listed by Trade Name. Fungicides that are systemic (penetrant) have a single site of action upon the target organisms' physiology and are particularly prone to developing resistance. Use systemic fungicides with a single site of action once per season. Use the most effective chemical against a particular pest first. Do not apply fungicides with a high risk of resistance development (systemic, single mode of action such as Group 11 strobilurins) when disease is severe as this situation results in high selection pressure upon the pathogen.

There are many other techniques that can help delay the onset of resistance. Many resistance management techniques help minimize the use of pesticides so a lower proportion of each pest generation is exposed to the toxin.

  • Integrate chemical controls with effective cultural, mechanical, physical, and genetic management options.
  • Scout, monitor, and use action thresholds to determine if fungicide applications are necessary.
  • Good spray coverage helps do the job right the first time and avoids unnecessary repeat applications. Use the proper size nozzles at the correct angle or orientation and an adequate amount of water per acre.
  • Tank mixes of systemic materials with contact fungicides help delay the onset of resistance to the systemic fungicides. Most contact fungicides have a multi-site mode of action (FRAC Group M plus a number).

NOTE: There is no relationship between insecticide groups, herbicide groups, and fungicide groups. For example, there is no problem with using a Group 1 herbicide and a Group 1 insecticide or fungicide.

Toxicity of Fungicides & Bactericides

All pesticides are poisonous. However, some are more toxic than others. The toxicity of the pesticide is usually stated in the precaution on the label. For example, a skull and crossbones figure and the signal word "Danger" are always found on the label of highly toxic (Toxicity Class I) materials. Those of medium toxicity (Toxicity Class II) carry the signal word "Warning". The least toxic materials (Toxicity Class III) have the signal word "Caution". The toxicity of a pesticide is expressed in terms of oral and dermal LD50. LD50 is the dosage of poison that kills 50% of test animals (usually rats or rabbits) with a single application of the pure pesticide for a given weight of the animal (mg/kg of body weight). The lower the LD50 value, the more toxic the material. Oral LD50 is the measure of the toxicity of pure pesticide when administered internally to test animals. Dermal LD50 is the measure of the toxicity of pure pesticide applied to the skin of test animals. Generally, an oral application is more toxic than a dermal one.

Fungicides and Bactericides Alphabetically Listed by Trade Name

Fungicides and Bactericides Alphabetically Listed by Trade Name Evonne Gong

The symbol OG indicates a pesticide that has been listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. REI = Re-Entry Interval expressed in hours (h). At the time of writing, all products listed were registered in at least one New England state. Check registration status in your state before using any product.

3336 F (thiophanate-methyl): A systemic fungicide with broad-spectrum control. Also labeled for greenhouse transplants. REI 12h, Group 1

42-S Thiram (thiram): A seed treatment with a wide host range. REI 24h, Group M03 

Abound F (azoxystrobin): Broad-spectrum fungicide. REI 14h, Group 11

Actigard 50 WG (acibenzolar-S-methyl): Plant defense activator used for bacterial diseases and downy mildews. REI 12h, Group P01

Actino-IronOG (Streptomyces lydicus WYEC 108 + molybdenum + iron): A biological soil and seed treatment for Fusarium, Rhizoctonia, Pythium, and Phytophthora with added iron and humic acid. May be used in greenhouse. REI 4h, Group BM02 

Actinovate AG (Streptomyces lydicus strain WYEC): Biological for greenhouse use only in vegetable crops. REI 4h, Group NC

Agclor 310 (sodium hypochlorite): A commercial bleach solution registered for use to control postharvest rots of vegetables. Group NC

Affirm WDG (polyoxin-D): Broad-spectrum fungicide for foliar and soilborne diseases. May be used in greenhouse. REI 4h, Group 19

Agri-Fos (phosphorus acid): A systemic fungicide active against Pythium, Phytophthora, Fusarium, Rhizoctonia and downy mildew. REI 4h, Group P07

Agri-Mycin 17 (streptomycin sulfate): A bactericide. REI 12h, Group 25

Aliette WDG (fosetyl Al): A fungicide active against Pythium, Phytophthora, and downy mildew. REI 12h, Group P07

Apron XL (mefenoxam): A seed treatment active against Pythium and Phytophthora seed rot and damping-off and systemic downy mildews of certain crops. REI 48h, Group 4

Aprovia Top (benzovindiflupyr + difenoconazole): For many diseases of cucurbits, legumes, peppers, tomatoes, and sweet potato. REI 12h, Groups 3 & 7

Ariston (chlorothalonil + cymoxanil): Labeled for several diseases on several crops. REI 12h (see label), Groups M5 & 27

BadgeX2OG and SC (copper oxychloride + copper hydroxide): A bactericide and fungicide. REI 24/48h (See label), Group M01

Basic Copper 53OG (basic copper sulfate): A broad-spectrum fungicide. REI 48h, Group M01

Bio-Save 10 LPOG (Pseudomonas syringae ESC-10): Labeled for postharvest decay of seed and storage of potato and sweet potato. Group NC

Bio-TamOG (Trichoderma aperellum, T. gamsii): Biological soil treatment for most crops. REI 4h, Group BM02

Blocker (4F, 10G) (PCNB): Soilborne diseases of brassicas, beans and peas, garlic, tomatoes, and pepper. REI 12h, Group 14

BotryStopOG (Ulocladium oudemansii U3 Strain): A biological control for Botrytis and Sclerotinia diseases. REI 4h, Group BM02

Bumper (propiconazole): Diseases of corn, celery, carrot, Swiss chard, and bulb crops. REI 12h, Group 3

Bravo (Weather Stik, Ultrex, ZN) (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M05

Cabrio EG (pyraclostrobin): A broad-spectrum fungicide for bulb, cucurbit, fruiting, and root vegetables. REI 12h, Group 11

Cabrio Plus (pyraclostrobin + metiram): For management of certain diseases of potato. REI 24h, Groups 11 & M03

Cabrio Team (pyraclostrobin + dimethomorph): For potato diseases. REI 12h, Groups 11 & 40

Camelot OOG (copper soap): Copper product labeled for greenhouse use on vegetable transplants. REI 4h, Group M01

Cannonball WG (fludioxonil): For management of Sclerotinia, Botrytis and other pathogens on various vegetables. REI 12h, Group 12

Catamaran (potassium phosphite + chlorothalonil): broad-spectrum fungicide and plant activator. REI 12h, Groups P07 & M05

CeaseOG (Bacillus subtilis QST 713): Biological protectant fungicide. REI 4h, Group BM02

Champ WGOG (copper hydroxide): Broad-spectrum fungicide and bactericide. REI 48h, Group M01

Champ (Dry Prill, Formula 2F) (copper hydroxide): Broad-spectrum fungicide and bactericide. REI 24/48h, Group M01

ChampION++OG (copper hydroxide): Copper fungicide. REI 48h, Group M01

CompanionOG (Liquid, WP) (Bacillus subtilis strain GB03): Biological fungicide. REI 4h, Group BM02

Companion Maxx WP (Bacillus subtilis strain ENV503): A biological fungicide. REI4 h, Group BM02

Contans WGOG (Coniothyrium minitans): For Sclerotinia sclerotiorum and Sclerotinia minor diseases. (Bayer formula not labeled for tomato). REI 12h, Group NC

Convergence (Bacillus amyloliquefaciens strain D747): A broad-spectrum biological preventive product labeled for corn and legume vegetables. REI 4h, Group BM02. 

CuevaOG (copper octanoate): A broad-spectrum fungicide and bactericide. REI 4h, Group M01

Cuprofix Ultra 40 Disperss (basic copper sulfate): A broad-spectrum fungicide. REI 48h, Group M01

Cuproxat, Cuproxat FLOG (basic copper sulfate): A broad-spectrum fungicide. REI 48h, Group M01

Curzate 60 DF (cymoxanil): For late blight of potato and tomato and downy mildews of cucurbits and lettuce. REI 12h, Group 27

Custodia (azoxystrobin + tebuconazole): A broad-spectrum fungicide labeled for foliar diseases of corn and some bulb vegetables. REI 12h, Groups 3 & 11

DiTera DFOG (Myrothecium verrucaria Strain AARC-0255): For management of plant parasitic nematodes. REI 4h, Group NC

Dithane (M-45, F-45 Rainshield) (mancozeb): A broad-spectrum, protectant fungicide. REI 24h, Group M03

Decree 80 WDG (fenhexamid): Botrytis control in greenhouse transplants. REI 12h, Group 17

Dexter Maxx (mancozeb + azoxystrobin): a broad-spectrum fungicide. REI 24h, Groups M03 & 11

Double NickelOG (55, LC) (Bacillus amyloliquefaciens strain D474): Microbial fungicide. REI 4h, Group BM02

Dynasty (azoxystrobin): A broad-spectrum seed treatment fungicide for seedborne diseases. REI 4h, Group 11

Echo (90DF, 720) (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M05

EcoSwingOG (extract of Swinglea glutinosa): Preventive biological fungicide for Alternaria leaf spot, Botrytis, and powdery mildew on many crops. Also labeled for greenhouse use. Activates ISR (induced systemic resistance). REI 4h, Group BM01

Elantus (azoxystrobin + benzovindiflupyr): For suppression of certain soilborne diseases in potatoes. REI 12h, Groups 11 &7

Elumin (ethaboxam): For management of oomycetes of brassicas, cucurbits, and solanaceous vegetables. REI 12h, Group 22.

Emblem (fludioxonil): For greenhouse use only on plants and transplants of listed crops. REI 12h, Group 12

Endura (boscalid): A protectant fungicide for legumes, brassicas, bulb vegetables, fruiting vegetables, lettuce, and root and tuber vegetables. REI 12h, Group 7

Equus 720 SST (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M05

Flint (trifloxystrobin): A strobilurin fungicide with broad-spectrum activity. REI 12h, Group 11

Fontelis (penthiopyrad): A fungicide with broad host clearance for leaf spots, blights, anthracnose, and Sclerotinia diseases. REI 12h, Group

Forum (dimethomorph): A fungicide for use against Phytophthora and downy mildew of bulb, cucurbit and fruiting vegetables, lettuce, potatoes, and tomatoes. REI 12h, Group 40

Fosphite (potassium salts of phosphorus acid): A fungicide active against Pythium, Phytophthora, and downy mildews. REI 4h, Group P07

Gavel 75 DF (zoxamide + mancozeb): A broad-spectrum protectant fungicide for disease control in potatoes, cucurbits, and tomatoes. REI 48h, Groups 22 & M03

GEM 500 SC (trifloxystrobin): broad-spectrum fungicide. REI 12h, Group 11

Guarda (thyme oil): A botanical product for certain fungal and bacterial diseases. REI 0h, Group NC

Headline, Headline SC (pyraclostrobin): A broad-spectrum strobilurin fungicide for use in legumes, corn, tuberous, and corm vegetables. REI 12h, Group 11

Headline AMP (pyraclostrobin + metconazole): For diseases of corn. REI 12h, Groups 11 & 3

Heritage (azoxystrobin): Preventative and curative broad-spectrum fungicide. See supplemental label for use on vegetable transplants grown in the greenhouse. REI 4h, Group 11

HowlerOG, Howler EVOOG (Pseudomonas chlororaphis strain AFS009): Active on a wide range of soil and foliar diseases. May be used in greenhouse. REI 4h, Group BM02

Incognito (4.5 F, 85 WDG) (thiophanate-methyl): A systemic fungicide with broad-spectrum control. REI varies with crop; See label. Group 1.

Initiate (720, ZN) (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M05

Inspire Super (difenoconazole + cyprodinil): For powdery mildew. REI 12h, Groups 3 & 9

Iprodione 4L AG (iprodione): For Alternaria, BotrytisSclerotinia, and Rhizoctonia diseases, in beans, broccoli, carrots, dry bulb onions, and lettuce, and white rot of garlic. REI 24h, Group 2

JMS Stylet-Oil, Organic JMS Stylet-OilOG (paraffinic oil): Protection against fungal diseases and aphid-transmitted viruses. Also labeled for greenhouse use. REI 4h, Group NC

KaligreenOG (potassium bicarbonate): Powdery mildew and other foliar diseases. REI 4h, Group NC

KalmorOG (copper hydroxide): A broad-spectrum bactericide and fungicide. REI 24/48h, Group M01

Kentan DF (copper hydroxide): A broad-spectrum bactericide and fungicide. REI 48h, Group M01

K-Phite 7LP (phosphorus acid): a systemic fungicide and bactericide for Pythium, Phytophthora, and downy mildew; also labeled for greenhouse transplant production. REI 4h, Group P07

Kocide (2000, 2000 OOG, 3000, 3000 OOG) (copper hydroxide): A broad-spectrum bactericide and fungicide. REI 48h, Group M01

Kumulus DFOG (sulfur): broad-spectrum fungicide, particularly for powdery mildew. REI 24h, Group M02.

LifeGard (LCOG, WGOG) (Bacillus mycoides isolate J):A preventive biological plant activator for use outdoor or in covered structures. REI 4h, Group P06

Luna Experience (fluopyram + tebuconazole): For control and suppression of fungal diseases of various vegetables. REI 12h, Groups 3 & 7

Luna Flex (fluopyram + difenoconazole): For control and suppression of fungal diseases of various vegetables. REI 12h, Groups 7 & 3 

Luna PRO (fluopyram + prothioconazole): For fungal diseases of potatoes. REI 12h, Groups 7 & 3 

Luna Sensation (fluopyram + trifloxystrobin): For management of foliar and soilborne diseases of several crops. REI 12h, Groups 7 & 11

Luna Tranquility (fluopyram + pyrimethanil): For fungal diseases of potato. REI 12h, Groups 7 & 9

ManKocide (mancozeb + copper hydroxide): A broad-spectrum fungicide and bactericide. REI 48h, Groups M03 & M01

Manzate (Max, Pro-Stick) (mancozeb): A broad-spectrum fungicide. REI 24h, Group M03

MasterCop (copper sulfate pehtahydrate): A broad-spectrum fungicide and bactericide. REI 48h, Group M01

Maxim 4FS (fludioxonil): A seed treatment fungicide for seedborne and soilborne fungi of several vegetable crops. REI 12h, Group 12

Maxim MZ (fludioxonil + mancozeb): A seed treatment fungicide for certain diseases of potato. REI 24h, Group 12 & M03

Maxim PSP (fludioxonil): A seed treatment fungicide for certain diseases of potato. REI 12h, Group 12

MeloCon (LCOG,WGOG) (Purpureocillium lilacinum strain 251): For transplant treatment with broad activity against various plant parasitic nematodes. REI 4h, Group NC 

Merivon Xemium (fluaxapoxad + pyraclostrobin): For fungal diseases including powdery mildew. REI 12h, Groups 7 & 11

Mertect 340-F (thiabendazole ): A seed treatment for fungal seedborne and soilborne diseases. REI 12h, Group 1

Mettle 125 ME (tetraconazole): A systemic fungicide labeled for various fruiting vegetables and cucurbits. REI 12h, Group 3 

Micora (mandipropamid): Oomycete fungicide labeled for greenhouse use (limited to structures with permanent flooring ONLY). REI 4h, Group 40

Microthiol DisperssOG (sulfur): A protectant fungicide particularly useful for powdery mildew. May be used in greenhouse. REI 24h, Group M02

Microfine SulfurOG (sulfur): A protectant fungicide particularly useful for powdery mildew. REI 24h, Group M02

Micro SulfOG (sulfur): A protectant fungicide particularly useful for powdery mildew. May be used in greenhouse. REI 24h, Group M02

Mildew CureOG (cottonseed, corn, and garlic oils): For powdery mildew management. REI 0h. Group NC

MilStop SPOG (potassium bicarbonate): For powdery mildew and other foliar diseases of greenhouse crops. REI 12h, Group NC

Miravis Prime (pydiflumetofen + fludioxonil): A preventive fungicide labeled for various fruiting vegetables, cucurbits, and potatoes. REI 12h, Groups 7 & 12

M-PedeOG (potassium salts of fatty acids): For powdery mildew management, labeled for greenhouse use. REI 12h, Group NC

Moncoat MZ (flutolanil + mancozeb): Potato seed piece treatment for late blight. REI 24h, Groups 7 & M03

Moncut SC (flutolanil): For control of soilborne diseases of brassicas and potatoes. REI 12h, Group 7

Monsoon (tebuconazole): A broad-spectrum foliar fungicide with curative and preventive action. REI 12h, Group 3            

Mural (azoxystrobin + benzovindiflupyr): Broad-spectrum fungicide for foliar applications for greenhouse-grown vegetable transplants grown for resale to consumers. NOT for transplants intended for commercial field use. REI 12h, Groups 11 & 7

MycoStopOG (Streptomyces griseoviridis K61): Biological seed or soil treatment. REI 4h, Group BM02

NemaClean 10% WPOG (Purpureocillium lilacinum strain PL11): For management of plant parasitic nematodes. REI 12h, Group NC 

Nevado 4F (iprodione): For Alternaria, Botrytis, RhizoctoniaSclerotinia, and Stemphylium diseases in beans, broccoli, carrots, brassicas, dry bulb onions, potatoes, and lettuce, and white rot of garlic. REI 24h, Group 2

Nordox 75 WGOG (cuprous oxide): A broad-spectrum fungicide and bactericide. REI 12h, Group M01

Nu-Cop (3L, 50DFOG, 50WPOG, HBOG) (copper hydroxide): Copper fungicide and bactericide. Some formulations may be applied in greenhouse. REI 24/48h, Group M01

Nutrol (potassium dihydrogen phosphate): Protectant fungicide for powdery mildew. REI 4h, Group P07

Nufarm T-Methyl (70WSB, SPC4.5F) (thiophanate-methyl): A systemic fungicide with broad-spectrum control. REI varies with crop; see label, Group 1

ObtegoOG (Trichoderma aperellum strain ICC012 + T. gamsii strain ICC 080): Biological soil treatment for most crops. REI 4h, Group BM02

Omega 500F (fluazinam): Phytophthora, downy mildew, leaf spots, Sclerotina and Sclerotium diseases; late blight and white mold of potatoes. REI 48h, Group 29

Omega Top MP (fluazinam): For management of late blight and white mold of potatoes. REI 12h, Group 29

Organocide 3-in-1 Garden SprayOG (sesame oil): Broad-spectrum biofungicide. Group NC

Orius 3.6F (tebuconazole): For onion diseases, rusts, powdery mildews, and other fungal diseases of select crops. REI (varies with crop, see label), Group 3

Orondis Opti Premix (chlorothalonil + oxathiapiprolin): A systemic and contact fungicide for diseases of potatoes, cucurbits, and fruiting vegetables. REI 12h, Groups M05 & 49

Orondis OD (Ultra A, Gold 200, Opti A) (oxathiapiprolin): For Phytophthora diseases and downy mildew in several crops. REI 4h, Group 49

Orondis Ultra (oxathiapiprolin + mandipropamid): Phytophthora diseases and downy mildew in several crops. REI 4h, Groups 49 & 40

OSO 5% SCOG (polyoxin D zinc salt): Broad-spectrum fungicide for foliar and soilborne diseases. REI 4h, Group 19

OxiDate 2.0OG (hydrogen dioxide + peroxyacetic acid): Preventive biocide. REI 0/1h (see label), Group NC

OxiPhos (phosphorus acid + hydrogen peroxide): Broad-spectrum preventive biocide. REI 4h, Group P07

Pageant TR Intrinsic (pyraclostrobin + boscalid): For diseases of greenhouse-grown cucurbits, fruiting vegetables, and leafy greens; and cucurbit, fruiting vegetable, and leafy green transplants for the home consumer market only (NOT for transplants for commercial field production). REI 12h, Groups 7 & 11

Penncozeb (75DF, 80WP) (mancozeb): A broad-spectrum fungicide. REI 24h, Group M03

PhD (polyoxin D zinc salt): Broad-spectrum fungicide for foliar and soilborne diseases of various vegetables. REI 4h, Group 19

Phyton 35 (copper sulfate): Broad-spectrum fungicide and bactericde. Labeled for greenhouse use on vegetable transplants. REI 48/24h (see label), Group M01

Phostrol (phosphorus acid): A fungicide for Pythium, Phytophthora, and downy mildew. REI 4h, Group P07

Polyram 80 DF (metiram): For early and late blight in potatoes. REI 12h, Group M03

Potato Seed Treater 6% (mancozeb): Potato seed piece treatment for Fusarium dry rot. REI 24h, Groups M03

Presidio 4SC (fluopicolide): A locally systemic fungicide effective against Phytophthora and downy mildews of bulb, cucurbit, fruiting, and leafy vegetables. REI 12h, Group 43

PreStop WGOG (Clonostachys rosea J1446): Preventative biological fungicide that can be incorporated into media, applied as a drench or as a foliar spray. REI 4h, Group NC

Previcur Flex (propamocarb): A fungicide for oomycetes. Previcur should be mixed with Bravo, Maneb, or Mancozeb to prevent development of resistance. REI 12h, Group 28

Priaxor Xemium (fluxapyroxad + pyraclostrobin): For disease control and in beans, tomato, peas, potato, and corn. REI 12h, Groups 7 & 11

Pristine (boscalid + pyraclostrobin): For use in bulb vegetables, carrots, cucurbits, and celery. REI 12h, Groups 7 & 11

Procure 480SC (triflumizole): Powdery mildew on brassica, cucurbits, and leafy vegetables. REI 12h, Group 3

Proline 480SC (prothioconazole): For diseases of corn, cucurbits, peas, and beans. REI 12h, Group 3

ProPhyte (phosphorus acid): Labeled for Pythium, Phytophthora, downy mildew. REI 4h, Group P07

PropiMax EC (propiconazole): Broad-spectrum fungicide for diseases of alliums, corn, carrot, table beet, and leafy and petiole vegetables. REI 12h, Group 3

PVentOG (Clonostachys rosea J1446): Preventative biological fungicide that can be incorporated into media or applied as a drench or as a foliar spray. REI 4h, Group BM02.

PVent Microbial WP (Clonostachys rosea strain J1446): Labeled for various seedborne and soilborne diseases. May be used in greenhouse. REI 12h, Group 3

Quadris (azoxystrobin): A strobilurin fungicide with broad-spectrum activity. REI 4h, Group 11

Quadris Opti (azoxystrobin + chlorothalonil): broad-spectrum fungicide for dry beans, cucurbit vegetables, potatoes, tomatoes, and onions. REI 12h, Groups 11 & M5

Quadris Ridomil Gold (azoxystrobin + mefenoxam): Labeled for potatoes only. REI 0h, Groups 11 & 4

Quadris Top (azoxystrobin + difenoconazole): broad-spectrum fungicide. REI 12h, Groups 11 & 3

Quash SC (metraconazole): For managment of several diseases, including white mold in beans, potato and sweet potato. REI 12h, Group 3

Quilt Xcel (azoxystrobin + propiconazole): A broad-spectrum fungicide for use in carrots, celery, corn, and bulb crops. REI 12h, Groups 11 & 3

Quintec (quinoxyfen): Fungicide for control of powdery mildew in cucurbits. REI 12h, Group 13

Rally 40 SWP (myclobutanil): A fungicide for powdery mildews and rusts of vegetable crops. REI 24h, Group 3

Rampart (phosphorus acid): Labeled for Pythium, Phytophthora, downy mildew, and some foliar diseases. May be used in greenhouse. REI 4h, Group P07

Ranman 400SC (cyazofamid): Effective against Phytophthora and downy mildew in cucurbits, tomatoes, bulb crops, and potatoes. REI 12h, Group 21

Reason 500 SC (femadione): A fungicide for use against Phytophthora, downy mildew, and white rust on tuberous and corm vegetables, tomatoes, bulb vegetables, lettuce, and cucurbit vegetables. REI 12h, Group 11

RegaliaOG (extract of Reynoutria sachalinensis) : Plant defense activator for fungal and bacterial diseases. REI 4h, Group P05

Reveille (phosphorus acid): Labeled for Pythium, Phytophthora, and downy mildew of various vegetables. REI 4h, Group P07

Resist 57 (phosphorus acid): A systemic fungicide labeled for Pythium, Phytophthora, Fusarium, Rhizoctonia, downy mildew of various crops, and silver scurf in potatoes. May be used in greenhouse. REI 4h, Group P07

Revus (mandipropamid): For use against downy mildew, late blight, and Phytophthora blight. REI 4h, Group 40

Revus Top (mandipropamid + difenoconazole): A broad-spectrum fungicide for potatoes and tomatoes. REI 12h, Groups 3 & 40

Rhyme (flutriafol): Labeled for several diseases on brassica, cucurbit, and fruiting vegetables. REI 12h, Group 3

Ridomil Gold (SL, GR) (mefenoxam): A fungicide active against Pythium, Phytophthora, and downy mildews. REI 48h, Group 4

Ridomil Gold Bravo SC (mefenoxam + chlorothalonil): A broad-spectrum fungicide containing 4.4% metalaxyl and 72% chlorothalonil effective against both oomycetes and true fungi. REI 48h, Groups 4 & M05

Ridomil Gold MZ WG (mefenoxam + mancozeb): A broad-spectrum fungicide containing 8% metalaxyl and 64% mancozeb effective against both oomycetes and true fungi. REI 48h, Groups 4 & M03

Ridomil Gold Copper (mefenoxam + copper hydroxide): A broad-spectrum fungicide containing 4.8% metalaxyl and 60% copper hydroxide effective against both lower and true fungi. REI 48h, Groups 4 & M01

RootShield (GranulesOG, WPOG) (Trichoderma harzianum Strain T-22): Biological soil treatment. REI 0h, Group NC

RootShield Plus (WPOG, GranulesOG) (Trichoderma harzianum Strain T-22 + T. virens Strain G-41): A biological fungicide for foliar and soil treatments. REI 0h, Group BM02

Roper (DF, DF Rainshield) (mancozeb): A broad-spectrum fungicide. REI 24h, Groups M03

Rovral 4F (iprodione): For Alternaria, Botrytis, Rhizoctonia, Sclerotinia, and Stemphylium diseases in broccoli, carrots, dry bulb onions, potatoes, and beans, and white rot of garlic. REI 24h, Group 2

Scala SC (pyrimethanil): Protective fungicide for bulb, tuberous, and corm vegetables. REI 12h, Group 9

Segovis (oxathiapiprolin): Labeled for downy mildew and Phytophthora. May be used in greenhouse and outdoor growing structures. REI 4h, Group 49

Serenade (ASOOG, OptiOG, SoilOG, MaxOG) (Bacillus subtilis QST 713): Biological protectant fungicide. REI 4h, Group BM02

Sil Matrix LCOG (potassium silicate): A broad-spectrum preventive fungicide. REI 4h, Group NC

SonataOG (Bacillus pumilus QST 2808): Biological protectant fungicide. REI 3h, Group BM02

SoilgardOG (Gliocladium birens strain GL-21, 12%): Labeled for damping-off and root rot management as soil or media treatment. May be used in greenhouse. REI 0h, Group NC

Sovran (kresoxim-methyl): For powdery mildew and gummy stem blight in cucurbits. REI 12h, Group 11

Spirato GHN (fludioxonil): For greenhouse use only on plants and transplants of listed crops. REI 12h, Group 12

Sporan EC2 (rosemary, clove, peppermint, and thyme oils): Contact fungicide with broad crop clearance. REI 0h, Group NC

StargusOG (Bacillus amyloliquefaciens F727): Broad-spectrum preventive biological fungicide for bacterial spot and blights, Botrytis blight, late blight, damping off and root rots, and downy mildew (depending upon crops, see label). REI 4h, Group BM02

Stratego, Stratego YLD (propiconazole + trifloxystrobin): For diseases of corn. REI 12h, Groups 3 & 11

Subdue MAXX (mefenoxam): For greenhouse-grown transplants for retail sale to consumers. For downy mildew, and soilborne Pythium and Phytophthora diseases. NOT for transplants grown for commercial field use. REI 0/48h (see label), Group 4

Suffoil-XOG (mineral oil): Fungicide, insecticide, and miticide labeled for greenhouse transplant production. REI 4h, Group NC

Sulfur (various formulations) (sulfur): For powdery mildew and rusts of select crops. REI 24h, Group M02

Super Tin 80 WP (triphenyltin hydroxide): For early blight and late blight of potato. Restricted-use pesticide. REI 48h, Group 30

Switch 62.5 WG (cyprodinil + fludioxonil): A protective fungicide for use in beans, brassica, carrot, herbs, leafy vegetables, and onions. REI 12h, Groups 9 & 12

Taegro 2.0 (Bacillus subtilis var. amyloliquefaciens FZB24): Biological for soilborne diseases in cucurbits, leafy vegetables, and fruiting vegetables. REI 4h, Group BM02

Tanos (famoxadone + cymoxanil): A penetrant fungicide with locally systemic and curative activities against downy mildews and late blight. REI 12h, Groups 11 & 27

Terraclor 400 (PCNB): A fungicide active against soilborne true fungi. Labeled for greenhouse transplant production. REI 12h, Group 14

Tilt (propiconazole): A protective fungicide for diseases of beans, beets, carrots, celery, onions, and corn. REI 24h, Group 3

Topguard (flutriafol): Labeled for some cucurbits and fruiting vegetables. REI varies with crop; see label, Group 3

Topguard EQ (azoxystrobin + flutriafol): Foliar diseases of brassicas, cucurbits, leafy, and fruiting vegetables. REI 12h, Groups 11 & 3

Topsin (4.5FL, MWSB) (thiophanate-methyl): A systemic fungicide with broad-spectrum control. REI varies with crop; see label, Group 1

Torino (cyflufenamid): For management of powdery mildew of cucurbits and certain fruiting vegetables. REI 4h, Group U06

Trebuset (pydiflumetofen): A broad-spectrum seed treatment fungicide labeled for certain legume vegetables. REI 12 H, Group 7

Triathlon BAOG (Bacillus amyloliquefaciens D747): A broad-spectrum microbial fungicide and bactericide. May be used in greenhouse. REI 4h, Group BM02

TrilogyOG (neem oil extract): Labeled for various fungal diseases. REI 4h, Group NC

Trionic 4SC (triflumazole): Powdery mildew and Alternaria. Also labeled for greenhouse use. REI 12h, Group 3

Trivapro (benzovindiflupyr + azoxystrobin + propiconazole): Labeled for corn diseases. REI 12h, Groups 3 & 7 & 11

Ultra Flourish (mefenoxam): A fungicide active against Pythium, Phytophthora, and downy mildew in various vegetable crops. REI 48h, Group 4

Vacciplant (laminarian): A broad-spectrum suppressant fungicide. May be used in greenhouse and pre-plant dip or soil drench. REI 4h, Group P04

Vangard WG (cyprodinil): For management of diseases of onions. REI 12h, Group 9

Velum Prime (fluopyram): A broad-spectrum fungicide and nematicide for use as a soil treatment. REI 12h, Group 7

Velum Rise (fluopyram + penflufen): Labeled for soilborne diseases of potatoes. Has nematicidal action. REI 12h, Group 7.

Vibrance (sedaxane): A seed treatment against seedling blight and damping off diseases. REI 12 h, Group 7

Vivando (metrafenone): For management of powdery mildew on cucurbits and fruiting vegtables. REI 12h, Group 50

ZeroTol 2.0OG (hydrogen dioxide): Preventive biocide labeled for greenhouse use. REI 0/1h (see label), Group NC

Zampro (ametoctradin + dimethomorph):A fungicide for downy mildew and Phytophthora diseases of potatoes, brassica, cucurbit, fruiting, bulb, and leafy vegetables. REI 12h, Groups 40 & 45

Ziram (76DF, Excel) (ziram): For use on tomatoes for anthracnose, Septoria leaf spot, and early blight. Do not use on cherry tomatoes. REI 48h, Group M03

Zing! (zoxamide + chlorothalonil): For management of diseases of cucurbits, garlic, onions, potatoes, and tomatoes. REI 12h, Groups 22 & M05

Information about Fungicides and Bactericides by A.I. (Table 26)

Information about Fungicides and Bactericides by A.I. (Table 26) Evonne Gong
ACTIVE INGREDIENT(S) TRADE NAME(S)

SIGNAL WORD1

RESISTANCE GROUP (FRAC2 CODE)

DERMAL LD50 (mg/kg) ORAL LD50 (mg/kg)
acibenzolar-S-methyl Actigard 50WG D P01 > 2,000 >5,000
ametoctradin & dimethomorph Zampro C 45 & 40 >5,000 >500 - <2,000
azoxystrobin Quadris F, Dynasty, Abound F

C

11 > 2,000 - 4,000 >2,000 -  5,000
azoxystrobin & benzovindiflupyr Elatus W 11 & 7 > 2,000 1, 049

azoxystrobin & chlorothalonil

Quadris Opti

W

11 & M05

>5,000

1,750

azoxystrobin & difenoconazole Quadris Top C 11 & 3 >2,000 >5,000
azoxystrobin & flutriafol Topguard EQ C 11 & 3 >5,000 >5,000
azoxystrobin & mefenoxam Quadris Ridomil Gold SL (co-pack) W 11 & 4 > 2,000 - 4,000 550 - >5,000

azoxystrobin & propiconazole

Quilt Xcel

W

11 & 3

>5,000

1030

azoxystrobin & tebuconazole Custodia W 11 & 3 >2,000 >300
Bacillus sp. 

Double NickelOG, CeaseOG Companion Maxx, ConvergenceOG, LifeGard, Leap, MinuetOG, SerenadeOG, Taegro, Sonata

C, W BM02 & P06 & 11A >2,000 - >5,050 >5,000
benzovindiflupyr Trivapro A D 7 > 5,000 550
benzovindiflupyr & difenoconazole Aprovia Top W 3 & 7 >5,000 1,750
benzovindiflupyr & azoxystrobin & propiconazole Trivapro W 7 & 11 & 3 >2,000 550

boscalid

Endura

W

7

>2,000

>2,000
chlorine Agclor 310

 D

NC >20,000 8,910
chlorothalonil Bravo (Weather Stik, Ultrex, Zn), Echo (720, 90 DF), Equus 720 SST, Initiate (720, Zn), Orondis

C ,W

M05 >2,000 - 10,000 >3,750 - 10,000
chlorothalonil & cymoxanil Ariston C M05 & 27 >5,050 >5,000
chlorothalonil & oxathiapiprolin Orondis Opti D M05 & 49 >2,000 >5,000
chlorothalonil & potassium phosphite Catamaran C M05 & P07 > 5,000 >5,000
Coniothyrium minitans ContansOG C BM02 >2,500 >2,500
copper hydroxide Champ (WGOG, Dry Prill, Formula 2 Flowable), KalmorOG, Kocide (2000, 2000-OOG, 3000, 3000-OOG), ChampION++OG, Nu-Cop (50DFOG, 50WPOG, HBOG), Kentan DF C, D M01 1,300->5,000 489 - 1,847
copper hydroxide & copper oxychloride  Badge (SC, X2OG) W M01 >2,000 >300
cuprous oxide Nordox 75 WGOG C M01 >2,000 3,165
copper octanoate Camelot O, Cueva C M01 >2,000 >2,000
copper sulfate (basic copper) Basic Copper 53OG, Cuprofix Ultra, Cuproxat (FLOG), Phyton 35, MasterCopOG C, W, D M01 >2,000 - 8000 1,000 - 2,521

cyazofamid

Ranman 400 SC

W

21

>5,000

>5,000

cyflufenamid Torino C U06 >2,000 <2,000
cymoxanil Curzate 60DF

W

27 >5,000 433

cyprodinil & fludioxonil 

Switch 62.5

D

9 & 12

>2,000

>5,000

ethaboxam Elumin  C 22 >5,000 >5,000

difenoconazole & cyprodinil

Inspire Super

C

3 & 9

>5,000

5,000

dimethomorph Forum Fungicide

D

40 >500 - <2,000 >4,000

famoxadone & cymoxanil 

Tanos

W

11 & 27

566 - 1732

>5,000

fenamidone

Reason 500 SC

W

11

>5,000

>5,000

fenhexamid

Decree 50 WDG

C

17

>2,000

>2,000

fluazinam

Omega 500F, Omega TopMP

W

29

>2,000

>5,000

fludioxonil Maxim4FS, Maxim PSP, Cannonball WG, Emblem, Scholar SC

C, W

12 >2,000 - >5,050 >2,000 - >5,000
fludioxonil & mancozeb Maxim MZ W 12 & M03 >5,000 >5,000

fluopicolide

Presidio

C

43

>4,000

>2,000

fluopyram Velum Prime C 7 >2,000 >2,000
fluopyram & penflufen Velum Rise C 7 N/A  >1,030
fluopyram & pyrimethanil Luna Tranquility C 7 & 9 >2,000 >2,000
fluopyram & difenoconazole Luna Flex W 3 & 7 N/A 1,030
fluopyram & prothioconazole Luna Pro W 3 & 7 >5,050 >5,000
fluopyram & tebuconazole Luna Experience W 7 & 3 >2,000 >2,000
fluopyram & trifloxystrobin Luna Sensation W 7 & 11 >2,000 2,000
flutolanil Moncut SC C 7 >4,000 >5,000
flutolanil & mancozeb Moncoat MZ C 7 & M03 >2,000 >5,000
flutriafol Topguard Fungicide, Rhyme C, W 3 >2,000 - >5,000 >2,000 - >3,000
fluxapyroxad & pyraclostrobin Priaxor Xemium, Merivon Xemium W, D 7 & 11 >5,000 >50 - <3,000
fosetyl aluminum Aliette WDG

C

P07 >2,020 >2,860
hydrogen peroxide & peroxyacetic acid Oxidate 2.0OG, ZeroTol 2.0OG D NC 1,040 - >2,000 332.1 - 3,622
iprodione Meteor, Rovral 4F, Nevado 4F

C

2 > 2,000 1,170- 2,981
laminarin Vacciplant W P04 >2,000 >2,000
mancozeb Penncozeb (75DF, 80WP), Manzate (Max, Pro-Stick), Dithane (M-45, F-45 Rainshield), Potato Seed Treater (6%, PS), Roper (DF, DF Rainshield)

C

M03 >2,000 - >10,000 >5,000

mancozeb & copper 

ManKocide

D

M03 & M01

>5,000

2,535

mandipropamid 

Revus, Micora

C

40

>5,000

>5,000

mandipropamid & difenoconazole

Revus Top

C

3 & 40

>5,000

2,958

mefenoxam Ridomil Gold (GR, SL), Apron XL, Ultra Flourish C, W 4 >2,000 - >5,000 550 - >5,000
mefenoxam & chlorothalonil Ridomil Gold Bravo SC

W

4 & M05 >5,050 5,000
mefenoxam & copper  Ridomil Gold Copper

D

4 & M01 >2,020 550
mefenoxam & mancozeb  Ridomil Gold MZ WG

W

4 & M03 >2,000 >2,000
metconazole Quash SC C 3 >5,000 1,750
metrafenone Vivando W 50 >5,000 >5,000
metiram Polyram 80 DF W M03 >2,000 >5,000
myclobutanil Rally 40WSP

D

3 >5,000 >2,500
oxathiapiprolin Orondis (Gold 200, Orondis OD) C 49 >5,000 >5,000
oxathiapiprolin & mandipropamid Orondis Ultra Premix C 49 & 40 >5,000 >5,000
PCNB Blocker (4F, 10G), Terraclor 400 W 14 >2,020 >5,050
penthiopyrad Fontelis C 7 >5,000 >5,000
phosphorus acid (salts of) Agri-Fos, Alude, Fosphite, K-Phite, Phostrol, ProPhyt, Rampart, Reveille

W

P07 >3,000 - >5,000 >5,000
polyoxin D zinc salt Oso 5% SC, AKA VeggieTurbo 5 SCOG, Ph-D, Affirm WDG C 19 >2,000 - >5,050 4,404 - >5,000
potassium bicarbonate KaligreenOG, MilStopOG W NC >2,020 - >5,000 2,700 - 3822
potassium dihydrogen phosphate Nutrol C NC >4,640 >2,000
propamocarb HCl Previcur Flex

W

28 >3,000 2,000 - 2,900
propiconazole Tilt, PropiMax EC, Bumper (41.8EC, ES)

D, C

3 >3,500 - >5,050 1,310 - 3,000

propiconazole & trifloxystrobin

Stratego

W

3 & 11

>5,050

4,757 - 4,830

prothioconazole Proline 480SC C 3 >5,000 >2,000 - <5,000
prothioconazole & trifloxystrobin Stratego YLD C 3 & 11 >5,000 >5,000
pydiflumetofen Trebuset D 7 >5,000 >2,000
pydiflumetofen & fludioxonil Miravis Prime W 7 & 12 >5,000 2,968

pyraclostrobin

Headline, Headline SC, Cabrio EG

C, W, D

11

200 - >2,000

2,000 - >5,000

pyraclostrobin & boscalid 

Pristine, Pageant Intrinsic

W

11 & 7

>2,000

1,490

pyraclostrobin & dimethomorph Cabrio Team C 11 & 40 >4,000 260

pyraclostrobin & metconazole

Headline AMP

W

11 & 3

>5,000

500

pyraclostrobin & metiram

Cabrio Plus

C

11 & M03

>2,000

>500 - <2,000

pyrimethanil

Scala SC

C

9

>5,000

4,505 - >5,000

quinoxyfen

Quintec

C

13

>2,000

>2,000

Reynoutria sachalinensis extract Regalia CGOG W P05 >5,000 >5,000
sedaxane Vibrance W 7 >5,500 2,975
streptomycin sulfate Agri-Mycin 17

W

25 >2,000 >5,000

sulfur

Microthiol DisperssOG, Kumulus DFOG, Micro SulfOG, Sulfur 6L, Microfine Sulfur

C, W

M2

>2,000

>5,000

tebuconazole Orius 3.6F C 3 >2,000 >2,000
tetraconazole Mettle 125 ME C 3 >2,000 >4,090

thiabendazole

Mertect 340-F

W

1

>5,050

>5,000

thiophanate-methyl Topsin (M WSB, 4.5 FL), Nufarm T-Methyl (70WSB, 4.5F), Incognito (4.5 F, 85 WDG)

C, W

1 >2,000 - >5,000 1,752 - >5,000
triphenyltin hydroxide Super Tin (80 WP, 4L) D 30 315 - 500 160 - 250
trifloxystrobin Flint Extra, Gem 500 SC

C

11 >2,000 >5,050

triflumizole

Procure 480 SC, Trionic 4SC

C

3

>5,000

>1,400

thiram

42-S Thiram

C

M03

>4,400

2,950

zoxamide & chlorothalonil Zing! C 22 & M05 >5,000 1,750 - 5,000
zoxamide & mancozeb Gavel 75 DF

C

22 & M03 >5,000 >5,000

Signal Word C = Caution; W = Warning: D = Danger

2 FRAC = Fungicide Resistance Action Committee 

The symbol OG indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more details. Note that for a given active ingredient, some products may be OMRI-listed while others are not.

Soil Fumigation Outdoors

Soil Fumigation Outdoors Evonne Gong

Soil fumigation is the most drastic measure that growers can perform to eradicate soil-borne pests and is often a method of last resort. Fumigants are general biocides; they are effective against fungi, bacteria, nematodes, soil insects, and weed seeds. They have several serious drawbacks:

  • Fumigants kill all organisms, even the beneficial ones that compete with or parasitize plant pathogens. They leave a biological vacuum which can be quickly reinfested with serious plant pathogens.
  • Fumigants have a high acute inhalation toxicity and are carcinogenic. They represent a hazard to humans, wildlife, and the environment.
  • Fumigants require specialized equipment and procedures to apply properly. They are usually applied by professional crop production services. Soil preparation, temperature, and rate of chemical will determine how effectively pests will be controlled.

Fall is the best time to fumigate. However, it can be very effective in spring with an appropriate post-treatment waiting period. Careful attention should be paid to soil temperature and moisture, as well as time of exposure as indicated on the product label. Plowing below the depth of treatment will mix non-treated and treated soil.

Read the label carefully before using fumigants. All chemical fumigants are restricted-use and require a 5-day Entry Restricted Period after application. 

Telone C-17 (dichloropropene + chloropicrin) or Telone II (dichloro-propene): 5.0-40 gal/A. Controls certain soil insects, nematodes, and soilborne fungi. Read and follow the instructions on the label carefully.

InLine (dichloropropene + chloropicrin): 13.0-20.5 gal/A. Controls certain soil insects, nematodes, and soilborne fungi. Read and follow the instructions on the label carefully.

Vapam HL (sodium methyl dithiocarbamate): 50-100 gal/A. Controls weeds, soil insects, nematodes, and soilborne fungi. Read and follow the instructions on the label carefully.

Insect Management

Insect Management Evonne Gong

For information on specific pests, use the search bar or see the appropriate crop section(s).

A successful insect management program can best be accomplished by combining IPM techniques, such as accurate pest identification, scouting, monitoring, and action thresholds, with biological and preventative control practices and selective insecticide applications if needed.

Use scouting and monitoring techniques to help assess and quantify insect populations over time.

Insecticides should be used only when action thresholds have been exceeded or damaging insect populations are present. Action thresholds help minimize insecticide use and crop damage. Avoid making routine insecticide applications to crops without evidence of insect activity and damage. All insects have natural enemies which, if conserved, can help regulate pest populations. Whenever possible, use selective insecticides that spare beneficial organisms and target the pest you wish to control. Broad-spectrum insecticides should be used as a last resort. All insecticide applications should be made with ample water and with nozzles directed so that they provide thorough coverage of the plant parts where insects hide. Alternate between insecticide classes or families to help manage insect resistance and extend the life of available products.

Insect Identification

Become familiar with the biology and life cycle of the major insect pests that attack crops on an annual basis. Understanding some basic insect biology often reveals when the pest is most vulnerable to control measures and helps lead to successful management efforts. Insects usually have either a simple life cycle, where they grow from egg to nymph to adult, or a slightly more complex cycle, where they mature from egg to larva and then go through metamorphosis in the pupal stage before becoming adults. Insects damage plants either as nymphs/larvae or as adults, or in both immature and adult stages. Learn to recognize the important life stages of major insect pests, and to recognize the crop injury or damage they produce to help determine when control efforts are needed. You should also be able to identify common beneficial insects and their immature stages (e.g., ladybeetle larvae) to avoid accidentally targeting natural enemies with insecticides. There are dozens of minor and secondary insect pests that may attack crops on a less frequent basis. Growers should have unknown insects and minor pests identified (see Diagnostics for Plant Problems) when they are suspected of causing crop damage. Misidentification often leads to the application of an ineffective pesticide and extensive or chronic crop damage. The application of ineffective or unnecessary pesticides can often reduce the populations of beneficial organisms or natural enemies and lead to secondary insect or mite outbreaks. An accurate diagnosis of the problem early on can often prevent years of frustration and needless expense. See the Northeast Vegetable & Strawberry Pest Identification Guide for help with identification.

Scouting and Monitoring

Crops should be inspected or scouted for insects or damage in a systematic fashion, on a regular basis throughout the growing season. For many crops and pests, this may mean walking fields weekly, or even more frequently, especially during critical or vulnerable plant development stages. Crops should be scouted in a systematic fashion by walking in an "M" or "W" pattern as you crisscross the field. Select plants (e.g., 25 or 50) at random and quantify the pest damage or count the individual insects. Record the average number of insects or damage per plant for each field. Scouting crops always saves money in the long run by allowing for early pest detection, reducing crop damage, and helping to maintain consistent quality. Sometimes scouting duties can be performed by other farm members or by hired consultants.

Monitoring insect populations with various types of traps (black light, pheromone, sticky, baited) can supplement or sometimes substitute for information normally gathered during crop scouting. Insect traps can help you quantify pest pressure that is difficult to see, such as the number of night-flying moths (e.g., corn earworm) present. The number of insects captured in traps is often used to time scouting activities, predict future pest levels, or is used in conjunction with action thresholds to time sprays and help avoid crop damage.

Action Thresholds

Action thresholds tell you when to spray to prevent economic damage to the crop. They also help you avoid applying insecticides to crops when insect populations are low or no pests are present. Thresholds can be based on the number of insects found per plant, the amount of injury or damage per plant, or the number of insects captured in a trap. Using action thresholds helps improve insecticide timing and effectiveness, minimize the number of applications and associated costs, and reduce crop damage and resistance problems. Use action thresholds whenever possible to help you decide if and when a spray is needed. Some insect thresholds are provided in this publication. See your state's Extension IPM personnel for local action thresholds for specific pests.

Preventative Controls

As mentioned in the introduction to the general Pest Management section, there are many preventative pest management options, such as cultural, mechanical, physical, genetic, and biological controls. These should be used whenever possible to help prevent insect pest problems. Preventative insect control options can be used alone or in combination to provide a complete management program. For example, plant inspections, eliminating weeds in the greenhouse, using screens, avoiding excess nitrogen applications, using plastic mulch, and preserving natural enemies can combine to produce a very effective aphid management program. If the distance between fields is great enough, crop rotation alone for Colorado potato beetle and cucumber beetles can often keep these tough pests from reaching damaging levels for the entire season. However, if only nearby fields are available, CPB can be effectively controlled by the use of a combination of two or more alternative controls, such as short-distance crop rotation, intervening trap crops or plastic-lined trenches, row covers, organic mulches, flaming, and microbial controls. Many preventative controls are mentioned in crop-specific IPM manuals, individual pest fact sheets, and on IPM websites.

Perimeter trap cropping utilizes a combination of control measures to concentrate and/or kill pests in the border area of the field. This technique involves planting one or more rows of an attractive plant species so that it completely encircles the less attractive main crop, and intercepts a migrating insect population. Often a chemical or microbial insecticide is used to spot-spray only the perimeter trap crop, sparing beneficials on the main crop, and substantially reducing insecticide use. Perimeter trap cropping has been shown to be effective at controlling diamondback moth larvae on cabbage, using collards as the trap crop; pepper maggots on bell peppers or eggplant, using hot cherry peppers as the trap crop; and cucumber beetles on summer squash, winter squash, cucumbers, melons, and sometimes pumpkins, using Blue Hubbard squash or another Cucurbita maxima variety as the trap crop. This technique may prove useful on related crops and against additional pests in the future.

Insecticides

Follow the label specifications for application rates. If the rate suggested in this guide does not agree with the current label, follow the label recommendations. Amounts of pesticides are in lb/A (pounds per acre), oz/A (ounces per acre) or pt/A (pints per acre) of commercial formulation, not A.I. (active ingredient), unless otherwise stated. The percentage by weight or concentration of A.I. varies with different brands of pesticides. The label gives pounds of A.I. in each commercial preparation. For example, Assail 30SG contains 30 lbs active ingredient per 100 lbs of formulated material.

The amount of insecticide recommended per acre should not be changed when varying gallonage of water per acre. Make sure a pesticide is labeled for concentrate application before using a low volume sprayer, air or mist sprayer, aircraft, or other concentrate application equipment.

Seed Treatments

Insecticide seed treatments may help protect your crop from soil insects and other early-season pests. Some of the seed treatments listed under various crops must be applied by a professionally licensed seed coating applicator. In some cases, the use or purchase of treated seed may be economical as it may result in a substantial reduction in pesticide use and increase the plant stand and yield in the field.

Resistance Management

Adult pests that survive an environmental hardship, such as the application of an insecticide, are likely to pass the trait that enabled them to survive on to their offspring. Repeat applications with the same type of pesticide will eventually remove almost all the susceptible individuals from a pest population and leave only those with the resistant gene. Because insects and mites go through generations quickly, resistance to an overused pesticide can develop in as little as three years.

To preserve the useful life of a pesticide, it is necessary to practice resistance management. The most effective way to extend the useful life of an effective product is to use it on a single pest generation only, and then on the next generation use a second pesticide with a different method of killing the pest (mode of action). On some pests particularly prone to developing resistance (e.g., Colorado potato beetle) it is best to use a product with a particular mode of action on one generation every second year only. To help select pesticides with a different mode of action, see chemical resistance groupings in Table 26. These resistance group numbers, or IRAC codes, were developed by the Insecticide Resistance Action Committee (IRAC). Products with the same code (number and letter) indicate products with a common mode of action. For multiple applications to the same crop, select products from different resistance groups.

Once a pest develops resistance to a group of pesticides with a particular mode of action, a higher rate of a similar chemical from the same group usually will not control the insect.

NOTE: There is no cross-resistance between insecticides, herbicides and fungicides. For example, there is no problem with using material from the herbicide Group 1 and an insecticide or fungicide from Group 1.

There are many other techniques that can help delay the onset of resistance. Most resistance management techniques help minimize the use of pesticides so that a lower proportion of each pest generation is exposed to the toxin.

  • Integrate chemical control with effective cultural, mechanical, physical, and genetic management options.
  • Use biological/microbial control agents or other selective pesticides to preserve natural enemies and help minimize the number of repeat applications.
  • Scout, monitor, and use action thresholds to ensure that applications are necessary.
  • Good spray coverage helps do the job right the first time and avoids unnecessary repeat applications. Use the proper size nozzles and the correct angle or orientation and an adequate amount of water per acre.
  • Time the application so that the most vulnerable insect life stage is exposed to the spray.
  • Use spot sprays, perimeter trap crop treatments, refuge plantings, and other methods that prevent the entire field or population from being treated to help preserve susceptible individuals.

Toxicity Rating of Insecticides

Insecticides vary greatly in their toxicity to humans and the environment. The toxicity of the insecticide is usually stated in the precaution on the label. For example, a skull and crossbones figure and the signal word "Danger" are always found on the label of highly toxic (Toxicity Class I) materials. Those of medium toxicity (Toxicity Class II) carry the signal word "Warning". The least toxic materials (Toxicity Class III) have the signal word "Caution". The toxicity of a pesticide is expressed in terms of oral and dermal LD50. LD50 is the dosage of poison that kills 50% of test animals (usually rats or rabbits) with a single application of the pure pesticide for a given weight of the animal (mg/kg of body weight). The lower the LD50 value, the more toxic the material. Oral LD50 is the measure of the toxicity of pure pesticide when administered internally to test animals. Dermal LD50 is the measure of the toxicity of pure pesticide applied to the skin of test animals. Generally, an oral exposure is more toxic than a dermal one.

Protecting Honeybees and Native Pollinators

Protecting Honeybees and Native Pollinators Evonne Gong

Honeybees and native pollinators visit vegetable crops during flowering and pollen shed. In crops such as cucurbits, their activity is crucial to the success of the crop. In other crops such as sweet corn or potato, bees are among many beneficial insects that seek out pollen or nectar resources as a food source, but crop yield does not depend upon their activity. Populations of honeybees and native pollinators have declined worldwide in recent years. Many factors have contributed to their decline. Pesticides applied to crops is one of these factors.

Pesticides applied to protect vegetable crops can affect pollinators through multiple routes of exposure: direct contact with sprays, contact with treated surfaces, pesticide-contaminated dust or pollen particles that are collected or adhere to the body of the insect (and may be taken back to hive), and ingestion of pesticide-contaminated nectar. Decisions made by the farmer make a difference in the exposure of bees and other beneficials to toxic levels of pesticides. While pesticides applied to crops are only one among many factors that threaten pollinators, this is one factor that growers can do something about. Taking precautions to minimize pesticide poisoning of pollinators in all crops is an important responsibility of all pesticide applicators.

Steps that can reduce pesticide exposure of pollinators:

  • Timing. Avoid applications when crop or weeds are in bloom. In crops that bloom over long periods, make applications late in the day or at night when pollinators are not foraging, and so that there is sufficient drying time before foraging begins. Control weeds.
  • Formulation. Wettable powders, dusts, and microencapsulated products have a greater toxic hazard than emulsifiable concentrates (or other liquid formulations with active ingredient in solution). Products that do not have acute toxicity but could cause injury to immature bees if carried back to the hive should not be applied in particulate form; this includes insect growth regulators.
  • Drying Time Before Exposure. Some products are highly toxic when wet, but much less so after the pesticide is dried. Spinosyns have this characteristic. Apply when there will be adequate drying time (usually 2-3 hours, depending on weather conditions and crop canopy) before pollinator activity.
  • Drift. Avoid drift to non-target areas near the field where blooming plants may be located. Windspeed and application equipment both influence drift.
  • Mode of Application. Soil and seed applications reduce exposure compared to foliar applications, unless plant uptake of the active ingredient produces residues in pollen or nectar. In the case of neonicotinoids, there is evidence that foraging bees may receive sublethal doses in pollen and nectar when cucurbit crops were treated with a systemic at early growth stages. This effect appears to be reduced by using lower rates and applying as early as possible, but may not be entirely eliminated by these methods. A sublethal dose may make bees more vulnerable to other stressors, or may combine with doses from contact with other treated plant material.
  • Acute Toxicity. Avoid applying insecticides rated as High or Medium (see descriptions below) directly to bees that are actively foraging on blooming crop or weeds. See Table 26 for information on insecticide active ingredients and toxicity. EPA registration includes an acute, single-dose laboratory study designed to determine the quantity of pesticide that will cause 50% mortality (LD50) in a test population of bees.
  • Read the label for bee hazard rating. If a pesticide is used outdoors as a foliar application and is toxic to pollinating insects, a “Bee Hazard” warning has generally been required to be included in the Environmental Hazards section of the label. The EPA bee toxicity groupings and label statements are as follows:
    • High (H): LD50 = 2 micrograms/bee or less. The label has the following statement: "This product is highly toxic to bees and other pollinating insects exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees or other pollinating insects are visiting the treatment area." If the residues phrase is not present, this indicates that the pesticide does not show extended residual toxicity.
    • Moderate (M): LD50 >2 micrograms/bee but <11 microgram/bee. The label has the following statement: "This product is moderately toxic to bees and other pollinating insects exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product if bees or other pollinating insects are visiting the treatment area."
    • Low (L): All others. No bee or pollinating insect caution required.

In this guide, Table 26 gives the bee toxicity rating (H, M, or L) for each active ingredient. In the Insect Control section for each crop, the bee toxicity rating is given for each insecticide listed.

Insecticides Alphabetically Listed by Trade Name

Insecticides Alphabetically Listed by Trade Name Evonne Gong

The symbol * indicates a Federally restricted-use pesticide

The symbol OG indicates a pesticide that has been listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production.

Some products are described in detail as examples for a given active ingredient (AI). For more information on other products with the same AI, refer to the example. Always refer to the specific product label before applying any product.

At the time of writing, all products listed were registered in at least one New England state. Check registration status in your state before using any product.

Abacus* (abamectin): See Agri-Mek for more information.

Abamex* (abamectin): See Agri-Mek for more information.

Abba* (abamectin): See Agri-Mek for more information.

Acenthrin* (acephate + bifenthrin): A mixture of two broad-spectrum neurotoxins. See Orthene and Brigade for more information on active ingredients in this product.

Acephate (acephate): See Orthene for more information.

Acramite (bifenazate): A selective miticide, which acts on contact as a nerve toxin with knockdown activity and long residual. Registered as a foliar spray for control of mites on cucurbits, eggplant, okra, peppers, field-grown tomatoes (for greenhouse tomatoes, see bifenzate product, Floramite), succulent beans and peas, and herbs. Relatively safe on beneficials. (Group 25, REI 12h)

Acronyx (imidacloprid): See Admire for more information.

Actara (thiamethoxam): A systemic neonicotinoid with translaminar activity, registered for use as a foliar spray for control of aphids, flea beetles, leafhoppers, whiteflies, and other pests on brassicas, cucurbits, fruiting vegetables, globe artichoke, leafy vegetables, mint, and root and tuberous vegetables. Do not use in greenhouses or on plants grown for use as transplants. Highly toxic to bees. (Group 4A, REI 12h)

Admire (imidacloprid): A systemic neonicotinoid, registered for use in soil, seed piece, and foliar applications. Labeled for use on cucurbits, herbs, brassicas, legumes, roots, bulbs, tubers, corms, globe artichoke, and fruiting and leafy vegetables for control of aphids, flea beetles, leafhoppers, whiteflies, thrips, and Colorado potato beetle. Also labeled for use in greenhouses on mature cucumber and tomato plants to control aphids and whiteflies. Do not apply to non-soil media or in hydroponic systems. Specific labeled application methods vary by crop. Highly toxic to bees. (Group 4A, REI 12h)

Advise (imidacloprid): See Admire for more information.

AgreeOG (Bacillus thuringiensis subspecies aizawai strain GC91): See XenTari for more information.

Agri-Mek* (abamectin): A locally systemic, selective chloride channel activator insecticide and miticide, derived from a metabolite of a soil bacterium, Streptomyces avermitilis. Registered for use as a foliar spray with translaminar activity to control spider mites on celeriac and sweet corn, thrips and leafminers on onions (bulb & green), and mites and leaf miners on cucurbits, dry beans, fruiting vegetables, herbs, tubers and corms, and non-brassica leafy greens. Also controls Colorado potato beetle and tomato and potato psyllid on fruiting vegetables and potatoes. Labeled for use on commercially produced greenhouse tomato for leafminer, mites, thrips, tomato psyllid, and tomato pinworm. Highly toxic to bees. (Group 6, REI 12h)

Akari (fenpyroximate): See Portal for more information.

Alias (imidacloprid): See Admire for more information.

Altus (flupyradifurone): See Sivanto for more information.

Amazin PlusOG (azadirachtin): See Azatin for more information.

Ambush* (permethrin): See Pounce for more information.

AmTide Imidacloprid (imidacloprid): See Admire for more information.

Anarchy (acetamiprid): See Assail for more information.

AncoraOG (Isaria fumosorosea Apopka Strain 97): See PFR-97 for more information.

Archer (pyriproxyfen): See Esteem for more information.

Arctic* (permethrin): See Pounce for more information.

Arvida (acetamiprid): See Assail for more information.

Asana* (esfenvalerate): A broad-spectrum, pyrethroid insecticide that works by contact and ingestion. Labeled for foliar applications on artichoke, beans, brassicas, carrots, cucurbits, fruiting vegetables, roots, sweet corn, and potatoes to control a wide variety of pests. Extremely toxic to fish and aquatic invertebrates and highly toxic to bees. (Group 3, REI 12h)

Assail (acetamiprid): A selective neonicotinoid, with translaminar activity, that controls sucking and chewing insects through contact and ingestion. Registered to control aphids, whitefly and other pests on asparagus, leafy vegetables, brassicas, fruiting vegetables, cucurbits, sweet corn, and succulent peas and beans. Also labeled for control of thrips on bulb vegetables, and aphids, Colorado potato beetle, flea beetle and other pests on tuberous and corm vegetables. (Group 4A, REI 12h)

Athena* (abamectin + bifenthrin): A mixture of a broad-spectrum pyrethroid and bacterium-derived chloride channel activator. See Agri-Mek and Brigade for more information on active ingredients in this product.

Avaunt (indoxacarb): A sodium channel blocker with translaminar activity that causes paralysis and death after being ingested on plant tissue. Labeled for use as a foliar spray on brassicas, cucurbits, fruiting vegetables, beets, leafy greens, leafy petioles, mint, and tubers and corms to control caterpillars. Also registered to control European corn borer and fall armyworm in whorl. Can be used in irrigation systems except for application to potatoes and sweet corn. Relatively safe for beneficials, but toxic to bees exposed to direct treatment. (Group 22, REI 12h)

Averland* (abamectin): See Agri-Mek for more information. 

Aza-DirectOG (azadirachtin): See Azatin for more information.

AzaGuardOG (azadirachtin): See Azatin for more information.

AzaMaxOG (azadirachtin): See Azatin for more information.

AzatinOG (azadirachtin): A natural insect growth regulator extracted from the seeds of the neem tree. Works by contact or ingestion against immature insect stages and has anti-feedant properties. Has some systemic activity and can be taken up by plant roots; may be used as a transplant drench. Registered for use as a foliar spray in field and greenhouse on all vegetable and vegetable transplants and herbs to control multiple pests. Short residual. Note: Azatin O is OMRI-listed, but Azatin XL is not. (Group un, REI 4h)

AzatrolOG (azadirachtin): See Azatin for more information.

Aztec* (beta-cyfluthrin + tebuprimphos): A mix of pyrethroid and organophosphate chemistries registered (VT only) for soil applications in sweet corn and popcorn for control of corn rootworms, cutworms, wireworms, seedcorn maggot, seedcorn beetle, and white grubs. (Group 1B, REI 48h)

Baythroid* (beta-cyfluthrin): A broad-spectrum, pyrethroid insecticide that works by contact or ingestion, labeled for foliar applications on brassicas, cucurbits, fruiting vegetables, leafy greens, dry beans, potatoes and other tubers and corms, carrots, radishes, and sweet corn for contact control of caterpillars, flea beetles, stink bugs, and other pests. Extremely toxic to fish and aquatic invertebrates and highly toxic to bees. (Group 3, REI 12h)

Batallion* (bifenthrin): See Brigade for more information

Belay (clothianidin): A neonicotinoid with long residual control, registered for use in foliar and soil applications on brassicas, cucurbits, and fruiting and leafy vegetables. Becomes systemic when applied to soil, and has translaminar activity when applied to foliage. Labeled to control aphids, flea beetles, stink bugs, leafhoppers, cucumber beetles, Colorado potato beetle, and other pests. Also labeled for use on tuberous and corm vegetables in foliar, seed piece, and soil applications to control aphids, Colorado potato beetle, wireworms, white grubs, and other pests. Highly toxic to bees. (Group 4A, REI 12h)

Beleaf (flonicamid): A pyridinecarboxamide with translaminar activity that works by contact and ingestion. Feeding stops rapidly and mortality will follow. Labeled for use on brassicas, cucurbits, fruiting vegetables, leafy greens, tubers and corms, root vegetables, greenhouse cucumbers and tomatoes, and mint for selective control of aphids, plant bugs, and greenhouse whitefly. (Group 29, REI 12h)

Besiege* (chlorantraniliprole + lambda-cyhalothrin): See Coragen and Warrior for more information.

Bifenture* (bifenthrin): See Brigade for more information.

Blackhawk (spinosad): See Entrust for more information.

Bifen* (bifenthrin): See Brigade for more information.

BiobitOG (Bacillus thuringiensis subspecies kurstaki strain ABTS-351): See Dipel for more information.

BioCeresOG (Beauveria bassiana Strain ANT-03): See Mycotrol for more information.

Bonide Garden Dust (sulfur): See Microthiol Disperss for more information.

Botanigard (Beauveria bassiana Strain GHA): See Mycotrol ESO for more information. Not approved for organic production. Notes: ES formulation may be phytotoxic on tomatoes. Maxx formulation contains pyrethrins.

Brigade* (bifenthrin): A broad-spectrum, pyrethroid insecticide and miticide. Labeled for use as a foliar spray on a wide variety of crops to control aphids, flea beetles, leafhoppers, stink bugs, caterpillars, and several other pests. Extremely toxic to fish and aquatic invertebrates and highly toxic to bees. Prohibited in areas where application may result in exposure to endangered species. (Group 3A, REI 12h)

Brigadier* (bifenthrin + imidacloprid): See Brigade and Admire for more information.

BT NowOG (Bacillus thuringiensis subsp. kurstaki strain EVB 113-19): See Dipel for more information.

Calantha* (ledprona): A new foliar insecticide utilizing RNA interference (RNAi) as a mode of action with the goal of providing effective and specific control of Colorado potato beetle (CPB). RNAi is a natural biological process which exists in most organisms and regulates the translation of messenger RNA, a step leading to the synthesis of proteins. Ingestion of certain manufactured double-stranded RNA (dsRNA) can activate this interference process in some organisms such as CPB, disrupting the expression of a vital enzyme in the insect’s metabolism and resulting in mortality within a few days of consumption. It is most effective on young larvae. This insecticide is not yet registered in Massachusetts but is registered for use in the rest of New England. (Group 35, REI 4h)

Captiva (Capsicum oleoresin extract + garlic oil): A repellant and insecticide made from concentrated plant extracts. Works by contact. Has anti-feedant, anti-egg laying, and irritant activity, and weakens cuticles of immature stages of some insect and mite pests. Registered for foliar applications in field and greenhouse on all food crops including greenhouse vegetable and transplant production to repel or suppress soft-bodied pests. (No resistance classification, REI 4h)

Capture* (bifenthrin): A broad-spectrum, pyrethroid insecticide and miticide, labeled for soil applications. Capture LFR can be mixed directly with liquid fertilizer or with water. Registered for use on a wide variety of crops to control wireworm, grubs, root maggot, cutworm, flea beetle larvae, and other soil dwelling pests. Extremely toxic to fish and aquatic invertebrates and highly toxic to bees. Prohibited in areas where application may result in exposure to endangered species. (Group 3A, REI 12h)

Carbaryl (carbaryl): See Sevin for more information.

Chlorpyrifos 4E AG (alternate brand name Quali-Pro Chlorpyrifos 4E) (chlorpyrifos): In November 2023, previously revoked food tolerances for chlorpyrifos were reinstated following a legal challenge. As of July 2024, EPA intends to issue a new proposed rule revoking all but 11 uses of chlorpyrifos, though NO USES ON VEGETABLES IN ANY NEW ENGLAND STATE ARE INCLUDED. Some food uses are currently allowed for this product only in some New England states for a limited time--see product label. Sale of existing stocks of this product is permitted until April 30, 2025; use of those stocks is permitted until June 30, 2025.

Citation (cyromazine): Labeled for vegetable transplants grown for consumer use. See Trigard for more information.

Clinch Ant Bait* (abamectin): A selective chloride channel activator insecticide that kills ants by ingestion and acts to cease viable egg production. Registered as a soil treatment in various crops to control fire ants. Long residual. (Group 6, REI 12h)

Closer (sulfoxaflor): See Transform for more information. Note: After being cancelled in 2015, sulfoxaflor registrations have been reinstated by the EPA under limited-use restrictions.

Confirm (tebufenozide): A selective insect growth regulator that induces a premature lethal molt within hours of ingestion. Labeled for use on brassicas, leafy vegetables, turnips, fruiting vegetables, and mint to control caterpillars. Not disruptive to beneficials and bees. (Group 18, REI 4h)

Consero* (spinosad + gamma-cyhalothrin): Labeled for corn and legumes. See Entrust and Declare for more information.

Coragen (chlorantraniliprole): A diamide that has contact activity, but is most effective through ingestion of treated plant material. Insects rapidly stop feeding, become paralyzed, and typically die within 1-3 days. Becomes systemic when applied to soil. Labeled for use as a foliar spray on artichoke, asparagus, bulb vegetables, corn, herbs, legumes, and roots and tubers to control caterpillars; and potatoes to control caterpillars and Colorado potato beetle. Also labeled as a foliar, drip irrigation, and soil treatment on brassicas, cucurbits, and fruiting and leafy vegetables to control caterpillars, leafminer and whitefly larvae, and Colorado potato beetle. Also labeled as a transplant water treatment for suppression of cabbage root maggot in leafy brassicas. Effective against difficult to control caterpillars such as beet and fall armyworm. Relatively safe for beneficials and non-target organisms. (Group 28, REI 4h)

Cormoran (novaluron + acetamiprid): See Rimon and Assail for more information.

CoStarOG (Bacillus thuringiensis subsp. kurstaki strain SA-12): See Dipel for more information.

Couraze (imidacloprid): See Admire for more information.

Cruiser (thiamethoxam): A systemic neonicotinoid commercial seed treatment that is taken up by the seedling plant and controls chewing and sucking insects through contact and ingestion. Labeled for use on cucurbits, legumes and potatoes to control aphids, leafminers, wireworms, and several other pests, including Mexican bean leaf beetle and thrips on legumes and Colorado potato beetle on potatoes. Highly toxic to bees. (Group 4A, REI 12h)

CrymaxOG (Bacillus thuringiensis subspecies kurstaki strain EG7841): See Dipel for more information.

Damoil (mineral oil): See Suffoil-X for more information.

Danitol* (fenpropathrin): A pyrethroid insecticide-miticide with contact activity. Labeled for use on cucurbits, fruiting vegetables, brassicas, and peas to control a wide variety of pests including aphids, caterpillars, flea beetles, spotted wing drosophila, Colorado potato beetle, and stink bugs. Extremely toxic to fish and aquatic organisms, and highly toxic to bees. (Group 3A, REI 24h)

Deadline M-Ps (metaldehyde): A toxic bait for slugs and snails. Labeled for use as a soil surface treatment for most vegetable crops. Not for direct application to or contamination of edible portions of the plant; to be applied as a band treatment between rows after formation of edible parts. Long-lasting; resistant to rain and watering. (No resistance classification, REI 12h)

Debug Turbo (azadirachtin + neem oil): See Azatin for more information.

Declare* (gamma-cyhalothrin): A microencapsulated broad-spectrum pyrethroid that acts on contact and via ingestion. Registered for use on brassicas, sweet corn, popcorn, cucurbits, fruiting vegetables, legumes, lettuce, onion, garlic, and tuberous and corm vegetables to control a wide variety of pests. Highly toxic to bees and extremely toxic to aquatic organisms. (Group 3A, REI 24h)

Defcon* (beta-cyfluthrin + tebupirimfos): For control of soil insects in corn. See Baythroid and Aztec for more information.

DeliverOG (Bacillus thuringiensis subsp. kurstaki): See Dipel for more information.

Delta Gold* (deltamethrin): A broad-spectrum, pyrethroid insecticide. Labeled for use on corn, cucurbits, bulb, fruiting, root, tuberous and corm vegetables, and globe artichoke to control a wide variety of pests. Extremely toxic to fish and aquatic invertebrates, and highly toxic to bees. (Group 3A, REI 12h)

DES-XOG (insecticidal soap): See M-Pede for more information.

Diazinon* (diazinon): An organophosphate with contact activity, labeled for use as a soil spray to be broadcast before planting and incorporated into the soil. Labeled for use on succulent legumes, tomatoes, and specific brassicas, melons, roots, and leafy greens to control cutworms, wireworms, and, on some crops, mole crickets and/or root maggots. Not to be used in greenhouses. Highly toxic to bees. (Group 1B, REI 2-4 days depending on crop)

Dimate (dimethoate): See Dimethoate for more information.

Dimethoate (dimethoate): A broad-spectrum organophosphate with systemic and contact activity against piercing, sucking, and chewing insects and mites. Labeled for use on asparagus, beans, some brassicas, leafy greens, melons (except watermelons), celery, fruiting crops, and succulent beans. Useful for control of pepper maggot in peppers. Not to be used in greenhouses. Highly toxic to bees. (Group 1B, REI 48h)

Dimilin* (diflubenzuron): A selective insect growth regulator that disrupts the molting process of insect larvae. Labeled for use on peppers to control armyworms and pepper weevils. Not disruptive to bees or other beneficial insects. (Group 15, REI 12h)

DipelOG (Bacillus thuringiensis subsp. kurstaki): A bacterium-derived insecticide that works by ingestion. Labeled for use on root, tuber, bulb, leafy green, brassica, legume, fruiting, and cucurbit vegetables to control caterpillars. Safe for bees and beneficial insects. Note: Dipel ES is not OMRI-listed, Dipel DF is. (Group 11A, REI 4h)

Discipline* (bifenthrin): See Brigade for more information.

Distance IGR (pyriproxyfen): An insect growth regulator that works by suppressing the development of the embryo within the egg and inhibiting metamorphosis of nymphs, larvae, and pupae into adults. Works by contact and ingestion. Labeled for use as a foliar spray with translaminar activity when used on indoor-grown fruiting vegetables to control greenhouse, silverleaf, and sweet potato whitefly, as well as fungus gnats and shore flies when applied as a soil drench. (Group 7D, REI 12h)

Durivo (chlorantraniliprole + thiamethoxam): See Coragen and Actara for more information.

Ecotrol G2OG (rosemary oil + peppermint oil): A broad-spectrum, plant-based granular insecticide, formulated from plant oils on ground corn cob. Incorporate as a band or with seeds at or after planting. Labeled for use on a variety of crops for control of wireworms, cutworms, root maggots, and symphylans. This product is exempt from EPA pesticide registration requirements.

Ecotrol PlusOG (rosemary oil + peppermint oil + geraniol): A broad-spectrum, plant-based granular insecticide that works on contact. Labeled for foliar application to a variety of crops for control of aphids, beetles, plant bugs, whiteflies, mites, thrips, and early stages of caterpillars. This product is exempt from EPA pesticide registration requirements.

EcozinOG (azadirachtin): See Azatin for more information.

Elevest (bifenthrin + chlorantraniliprole): See Brigade and Coragen for more information.

Empower* (bifenthrin): See Brigade (for foliar applications) or Capture (for soil applications) for more information. Granular formulations may not be applied in coastal counties.

Endeavor (pymetrozine): See Fulfill for more information.

Endigo* (lambda-cyhalothrin + thiomethoxam): See Warrior and Actara for more information.

EntrustOG (spinosad): A nerve and stomach poison derived from the soil bacterium, Saccharopolyspora spinosa. Registered for use as a foliar spray with some translaminar activity on asparagus, brassicas, bulb vegetables, corn, cucurbits, fruiting vegetables, herbs, leafy greens, legumes, roots, and tubers to control lepidopteran larvae, Colorado potato beetle, leafminers, thrips, and other pests. Helps conserve beneficial predators, but may be toxic to some parasites of insect pests. Toxic to bees for 3 hours following treatment. (Group 5, REI 4h)

Esteem (pyriproxyfen): An insect growth regulator that works by suppressing the development of the embryo within the egg and inhibiting metamorphosis of nymphs, larvae, and pupae into adults. Does not control adult insects. Labeled for use as a foliar spray with translaminar activity on dry bulb onions to control onion and western flower thrips and on legumes to control silverleaf and sweet potato whitefly. Not for use in irrigation systems. (Group 7D, REI 12h)

Ethos* (bifenthrin + Bacillus amyloliquefaciens strain D747): Insecticide + fungicide. Labeled for control of various insect and disease pests on corn, dried and succulent beans and peas, and potatoes. See Brigade (bifenthrin) and, in the Disease Management section, Double Nickel (Bacillus amyloliquefaciens strain D727) for more information.

Evergreen (pyrethrins + piperonyl butoxide): See Pyganic and Pyronyl Crop Spray for more information. This product is registered for greenhouse use only for several crops and pests. 

Exirel (cyantraniliprole): A diamide that has some contact activity, but is most effective through ingestion. Labeled for use as a foliar spray on brassica, bulb, cucurbit, fruiting, and leafy vegetables, as well as greenhouse-grown eggplant, pepper, and tomato to control sucking and chewing insects including lepidopteran larvae, aphids, flea beetle, leafminers, thrips, and whitefly. Highly toxic to bees. (Group 28, REI 12h)

Fanfare* (bifenthrin): See Brigade for more information.

Fastac* (alpha-cypermethrin): A broad-spectrum pyrethroid insecticide. Labeled for foliar applications on brassicas, sweet corn, cucurbits, fruiting vegetables, leafy vegetables, and legumes to control a wide variety of pests. Extremely toxic to fish and aquatic invertebrates and highly toxic to bees. (Group 3A, REI 12h)

Flagship (thimethoxam): For use in greenhouses on vegetable transplants for resale only. See Actara for more information.

Floramite (bifenazate): A selective contact carbazate miticide with knockdown activity and long residual. Labeled for use on greenhouse tomatoes (for field tomatoes, see bifenazate product, Acramite) to control mites. Relatively safe on beneficials. (Group un, REI 12h)

Force* (tefluthrin): A pyrethroid that works by ingestion and contact. Labeled for use in band and in-furrow soil applications at planting on sweet corn and popcorn to control wireworms, seedcorn maggots, white grubs, and other soil insect pests. (Group 3A, REI 48h)

Fulfill (pymetrozine): A selective hemipteran feeding blocker that works primarily by ingestion, but has some contact activity. Labeled for use as a foliar spray on potatoes and other tuberous roots and corms, asparagus, brassicas, cucurbits, and fruiting and leafy vegetables to control aphids. Translaminar, long residual. Low toxicity to beneficials, including bees, but do not apply to bees that are actively foraging. (Group 9B, REI 12h)

Fyfanon (malathion): See Malathion for more information.

GemstarOG (nuclear polyhedrosis virus of Helicoverpa zea): A selective biopesticide for control of Helicoverpa zea on several vegetables, fruits, and field crops. Larvae ingesting the virus stop feeding within several days, become pale and lethargic, and then die as the virus replicates throughout their bodies. Frequent application at low rates is usually more effective than infrequent application at high rates. (Group un, REI 4h)

GF-120 Naturalyte Fruit Fly BaitOG (spinosad): An insecticidal bait labeled for use as a foliar and soil spray on vegetable and food crops to control tephritid fruit flies. Highly toxic to bees if directly applied. (Group 5, REI 4h)

GnatrolOG (Bacillus thuringiensis subsp. israelensis): A bacterium-derived larvicide labeled for use as a soil drench on vegetable plants including brassicas, tomatoes, leafy vegetables, cucumbers, peppers, and eggplants to control fungus gnat larvae. (Group 11, REI 4h)

Golden Pest Spray OilOG (soybean oil): A soybean-derived horticultural oil that works as a contact insecticide, as well as a feeding and oviposition deterrent. Labeled for use in sweet corn for control of earworm, root worms, and fall armyworm. Also labeled for use on a range vegetable crops to control other soft-bodied insects. (No resistance classification, REI 4h)

GrandevoOG (Chromobacterium subtsugae strain PRAA4-1): A selective biological insecticide/miticide that works as a stomach poison upon ingestion. Labeled for use as a foliar spray or in chemigation for control of certain caterpillars, foliage-feeding beetles, aphids, whiteflies, mites, leafhoppers, and thrips on many vegetable crops. (No resistance classification, REI 4h)

Grizzly* (lambda-cyhalothrin): See Warrior for more information.

Harvanta (cyclaniliprole): A broad-spectrum diamide. Labeled for use in leafy vegetables, heading brassicas, and leafy and fruiting vegetables for caterpillars, flea beetles, thrips, stink bugs, and aphids (Group 28, REI 4h)

HeligenOG (Helicoverpa zea nucleopolyhedrovirus ABA-NPV-U): See Gemstar for more information.

Hero* (bifenthrin + zeta-cypermethrin): See Brigade and Mustang for more information.

Holster* (zeta-cypermethrin): See Mustang for more information.

Imidan (phosmet): A broad-spectrum organophosphate labeled for use on potato and sweet potato to control Colorado potato beetle, European corn borer, flea beetle, potato leafhopper, and other pests. Potatoes and sweet potatoes must be harvested mechanically. Highly toxic to bees. (Group 1B, REI 5 days)

Intrepid (methoxyfenozide): A selective diacylhydrazine insect growth regulator that works by ingestion. Labeled for use on leafy brassicas, other leafy greens, cucurbits, fruiting vegetables, root vegetables, sweet potato, globe artichoke, green onions, legumes, popcorn, and herbs. Controls caterpillars by causing a premature and incomplete lethal molt. Safe for bees and other beneficial insects. (Group 18, REI 4h)

Intrepid Edge (methoxyfenozide + spinetoram): See Intrepid and Radiant for more information.

Inspirato (methoxyfenozide): See Intrepid for more information.

Intruder (acetamiprid): See Assail for more information.

Invertid (methoxyfenozide): See Intrepid for more information.

JavelinOG (Bacillus thuringiensis subsp. kurstaki): See Dipel for more information. 

JMS Stylet OilOG (paraffinic oil): See Suffoil-X for more information. Note: Organic JMS Stylet Oil is OMRI-listed; JMS Stylet Oil is not.

Kanemite (acequinocyl): A selective miticide with knockdown and residual activity. Labeled for use as a foliar spray on fruiting vegetables, edible-podded beans, and edamame to control two-spotted spider mite, and on cucurbits, succulent shelled beans, and okra to control two-spotted spider mites and broad mites. Shows efficacy on all mite life stages. Relatively harmless to most predaceous mites and beneficial insects. (Group 20B, REI 12h)

Kilter* (imidacloprid + lambda-cyhalothrin): See Admire + Warrior for more information.

Knack (pyriproxyfen): An insect growth regulator that works by contact on immature stages. No activity against adult insects. Labeled for use as a foliar spray with translaminar activity on brassicas, cucurbits, succulent and dry legumes, and roots and tubers to control various whitefly species. Also labeled for use on tomatoes to control whiteflies, armyworms, tomato pinworm, thrips, and other pests, for other fruiting vegetables to control whiteflies, cabbage looper, green peach aphids, and tobacco hornworm, and for bulb vegetables to control onion thrips. (Group 7C, REI 12h)

Kontos Greenhouse and Nursery (spirotetramat): For use in greenhouses on vegetable transplants for resale only. See Movento for more information.

Lada (imidacloprid): See Admire for more information.

Lambda-Cy* (lambda-cyhalothrin): See Warrior for more information.

Lambda-T2* (lambda-cyhalothrin): See Warrior for more information.

LambdaStar*(lambda-cyhalothrin): See Warrior for more information.

Lamcap* (lambda-cyhalothrin): See Warrior for more information.

Lannate* (methomyl): A broad-spectrum carbamate insecticide with translaminar activity. Works on contact, and short-term via ingestion of treated foliage, on all pest life stages. Registered as a foliar spray on a variety of crops for control of aphids, caterpillars, and beetles, including brown marmorated stinkbug. Effective on melon aphids. Other aphids and some caterpillars, such as diamondback moth and cabbage loopers, tend to be resistant. Short residual. Highly toxic to bees. (Group 1A, REI 48h)

Leap (Bacillus thuringiensis subsp. kurstaki strain ABTS-351 + methyl salicylate): Insecticide + inducer of host plant resistance to control bacterial diseases. Labeled for use on cabbage, corn, tomato, and pepper to control caterpillar pests and suppress bacterial infections. See Dipel for more information.

Leprotec (Bacillus thuringiensis subspecies kurstaki strain EVB-113-19): See Dipel for more information.

Leverage* (imidacloprid + beta-cyfluthrin): See Admire and Baythroid for more information.

Macho (imidacloprid): See Admire for more information.

Magister (fenazaquin): A mitichondial electron transport inhibitor (METI) that acts on eggs, immature, and adult mites and certain insects. Also Group 39 fungicidal activity. Highly toxic to bees, fish, and aquatic invertebrates. (Group 21A, REI 12h)

Magus (fenazaquin): See Magister for more information.

MajesteneOG (Heat-killed Burkholderia spp.): See Venerate for more information. Also has a 2(ee) use as a seed treatment, in-furrow at planting, or as a soil drench for the suppression of wireworms, white grubs, as well as root-knot, dagger, cyst, stunt, and lesion nematodes attacking potato and sweet potato. (Group un, REI 4 h)

Malathion (malathion): An organophosphate insecticide that acts by contact as a nerve toxin. Registered as a foliar spray on a variety of vegetable crops to control a wide range of insect pests. Highly toxic to bees. (Group 1B, REI 12h to 2 days, depending on crop)

Malice (imidacloprid): See Admire for more information.

Mallet (imidacloprid): Labeled for use inside greenhouses through irrigation or drench application or as a foliar spray for vegetable transplants and nursery stock for resale only. See Admire for more information. Refer to specific product label before applying. 

Mantra (imidacroprid): For use in greenhouses on vegetable transplants for resale only. See Admire for more information.

Manticor (bifenthrin + pyraclostrobin): For in-furrow application in sweet corn; a group 3A insecticide + group 11 fungicide. See for more information Brigade for more information.

Marathon (imidacloprid): Labeled for use inside greenhouses for vegetable transplants and nursery stock for resale only. See Admire for more information.

Met52 (Metarhizium anisopliae Strain F52): Composed of spores of a naturally occurring insect pathogenic fungus. Spores attach to the insect and hyphae penetrate the exoskeleton, growing inside and causing death, usually taking 3-7 days from exposure, depending on temperature. Labeled for use as a foliar spray or soil drench on field and greenhouse onions to control thrips, and on field and greenhouse cucurbits, celery, lettuce, spinach, peppers, and tomatoes to control thrips, whiteflies, and mites. Persistence will generally be higher when incorporated into soil but may be effective for a few months even in foliar applications. The EPA reports that M. anisopliae strain F52 is not harmful to earthworms or to such beneficial insects as ladybeetles, green lacewings, parasitic wasps, honey bee larvae, and honey bee adults. (Group un, REI 0h when mechanically soil-incorporated, 4h otherwise)

Microfine sulfurOG (sulfur): See Microthiol Disperss for more information.

Microthiol DisperssOG (sulfur): Micronized wettable sulfur for use on a variety of crops to control mites. (Group M2 fungicide, no insect resistance classification, REI 24h)

Millenium (Steinernema carpocapsae): A biological control for ground-dwelling insects and certain borers. Entomopathogenic nematodes must be refrigerated and can not be frozen. See label for compatibility with various pesticides. (Group un, No REI)

Minecto Pro (abamectin + cyantraniliprole): See Agri-Mek and Verimark for more information.

Mite-E-Oil (mineral oil): See Suffoil-X for more information.

Mocap* (ethoprop): An organophosphate nematicide-insecticide that works as a nerve toxin. Labeled for soil applications on mint, potatoes, and sweet potatoes to control various soil pests. Extremely toxic to birds. (Group 1B, REI 48h)

Molt-XOG (azadirachtin): See Azatin for more information.

Montana (imidacloprid): See Admire for more information.

Movento (spirotetramat): A tetronic acid derivative insecticide that works primarily by ingestion against immature pest stages. Fertility of adult stages may also be reduced. It is taken up by leaves and translocated to become fully systemic. Registered as a foliar spray on several vegetable crops to control thrips, aphids, Swede midge, and other pests. Potentially toxic to bee larvae through residues in pollen and nectar, but not to adult honeybees. Not for use in greenhouses. (Group 23, REI 24h)

M-PedeOG (potassium salts of fatty acids): An insecticidal soap that works by contact as an insecticide, miticide, and fungicide. Registered for use as a foliar spray for most vegetable and herb crops for control of a variety of insect pests; also active against powdery mildew. Must be applied directly to and thoroughly cover target insects. Avoid treatment when plants are stressed. Can be phytotoxic to some crops; test on small plot. May harm beneficials. (No resistance classification, REI 12h)

Mustang* (zeta-cypermethrin): A pyrethroid insecticide that works by contact as a nerve toxin. Registered for use as a foliar spray on globe artichoke, brassicas, bulbs, sweet corn, cucurbits, fruiting vegetables, leafy greens, legumes, roots, and tubers for control of a wide variety of insect pests. Highly toxic to bees. Extremely toxic to aquatic organisms. (Group 3A, REI 12h)

Mycotrol ESO (Beauveria bassiana): A fungus that kills adults or larvae by penetrating the cuticle and growing inside the insect. Target pest must contact pesticide directly or be on treated foliage. Registered for use in field and greenhouse on most vegetable crops for control of grasshoppers, aphids, whiteflies, thrips, leafhopper, caterpillars and leaf-feeding beetles, including Colorado potato beetle. Approved for organic production by the Washington State Department of Agriculture. (No resistance classification, REI 4h) 

Nealta Miticide (cyflumetofen): A beta-ketonitrile contact miticide labeled for use on tomatoes to control tertanychid mites only. (Group 25, REI 12h)

NeemixOG (azadirachtin): See Azatin for more information.

Nemasys (Steinernema feltiae): A biological control for thrips in greenhouse operations and other uses. Entomopathogenic nematodes must be refrigerated and cannot be frozen. (Group un, No REI)

Nemasys G (Heterorhabditis bacteriophora): A biological control for white grubs and other uses. Entomopathogenic nematodes must be refrigerated and cannot be frozen. (Group un, No REI)

Nemasys L (Steinernema kraussei): A biological control for black vine weevil and other uses. Entomopathogenic nematodes must be refrigerated and cannot be frozen. (Group un, No REI)

Nudrin* (methomyl): See Lannate for more information.

Nufarm Abamectin* (abamectin): See Agri-Mek for more information.

Nuprid (imidacloprid): See Admire for more information.

Oberon (spiromesifen): A selective tetronic acid derivative insecticide and miticide with translaminar activity. Works on contact and by ingestion to kill juvenile stages of target pests, particularly whitefly pupae. Registered as a foliar spray on sweet corn, cucurbits, fruiting vegetables, leafy greens, brassicas, and tubers and corms for control of aphids, whiteflies, psyllids, and mites. Not for use in greenhouses. (Group 23, REI 12h)

Onyx* (bifenthrin): See Brigade for more information.

Ornazin (azadirachtin): See Azatin for more information.

Orthene (acephate): A systemic organophosphate insecticide that targets nerve and muscle tissue on contact. Registered for use as a foliar spray for beans, Brussels sprouts, cauliflower, celery, crisphead lettuce, mint, and peppers to control caterpillars and other pests. Highly toxic to bees. (Group 1B, REI 24h)

Pasada (imidacloprid): See Admire for more information.

Permethrin* (permethrin): See Pounce for more information.

PermaStar* (permethrin): See Pounce for more information.

Perm-Up* (permethrin): See Pounce for more information.

PFR-97OG (Isaria fumosorosea Apopka Strain 97): A naturally occurring fungus that penetrates the cuticle of insect pests. Labeled for foliar and soil applications on greenhouse and field-grown vegetable crops to control a variety of insect pests. (No resistance classification, REI 4h)

Piston (chlorfenapyr): See Pylon for more information.

Platinum (thiamethoxam): A selective systemic neonicotinoid. Works through ingestion, targeting nerve and muscle tissue. Registered as a soil treatment for brassicas, cucurbits, fruiting vegetables, leafy greens, roots, tubers, and corms for control of aphids, flea beetles, whiteflies, and other pests. Not for use in greenhouses or on plants grown for use as transplants. Highly toxic to bees. (Group 4A, REI 12h)

Portal (fenpyroximate): An insecticide and miticide that works on contact to disrupt pest species’ ability to generate energy. Registered for use as a foliar spray on corn, cucumbers, fruiting vegetables, melons, potatoes, and snap beans for control of leafhoppers, mites, psyllids, and whiteflies. Good rotational product to alternate with other chemistries. Low toxicity to bees and mammals. Extremely toxic to aquatic organisms. (Group 21A, REI 12h)

Pounce* (permethrin): A broad-spectrum pyrethroid insecticide that works as a nerve toxin. Registered for use as a foliar spray on a variety of crops for control of caterpillars and other pests. Extremely toxic to aquatic organisms and highly toxic to bees. (Group 3A, REI 12h)

PQZ (pyrifluquinazon): Selective insecticide for use for various sucking (sap-feeding) insects such as whiteflies, thrips, aphids, mealybugs, and leafhoppers on vegetable and fruit crops. (Group 9B, REI 12h)

PreferalOG (Isaria fumosorosea Apopka strain 97): See PFR-97 for more information.

Prev-AM Ultra (sodium tetraborohydrate decahydrate): An insecticide, miticide, and fungicide that utilizes borax to desiccate soft-bodied insects. Registered for use as a foliar spray on a range of crops to control aphids, caterpillars, thrips, whiteflies, and other pests. Also for control of downy mildew, powdery mildew, and late blight. (Group 25, REI 12h)

Prey (imidacloprid): See Admire for more information.

Proclaim* (emamectin benzoate): A selective avermectin insecticide, derived from a metabolite of the bacterium, Streptomyces avermitilis. Works through ingestion to target nerve and muscle tissue of lepidopteran larvae. Registered for use as a foliar spray with translaminar activity on brassicas, fruiting vegetables (except cucurbits), and leafy vegetables to control caterpillars. Not for use in greenhouses or on plants grown for use as transplants. Highly toxic to bees. (Group 6, REI 12h)

Prokil Cryolite (cryolite): A high rate per acre, fluorine-based insecticide that works as a stomach poison. Labeled for use as a foliar spray on broccoli, Brussels sprouts, cauliflower, melons, squash, and peppers to control several insect pests including flea beetles and some caterpillars. (Group un, REI 12h)

Province II (lambda-cyhalothrin): See Warrior for more information.

PureSpray Green (mineral oil): See SuffOil for more information.

PyganicOG (pyrethrins): A broad-spectrum botanical pyrethrum. A fast-acting contact toxin with a short residual, it decays rapidly in sunlight and soils. Registered for use in field and greenhouse on a variety of crops to kill a wide range of insects. Highly toxic to bees. (Group 3A, REI 12h)

Pylon Miticide (chlorfenapyr): A pyrrole insecticide and miticide which works on contact and via ingestion, causing the pest to be unable to generate energy. Has translaminar activity. Registered for use as a foliar spray in greenhouses on tomatoes, eggplant, and peppers, for control of caterpillars, mites, and thrips. (Group 13, REI 12h)

Pyrethrum TR (pyrethrins + piperonyl butoxide): See Pyronyl Crop Spray for more information. 

Pyronyl Crop Spray (pyrethrins + piperonyl butoxide): A broad-spectrum botanical pyrethrum mixed with a synergist (piperonyl butoxide) to improve efficacy. See Pyganic for more information.

Quasar (acetamiprid): See Assail for more information.

Radiant (spinetoram): A nerve and stomach poison derived from the bacterium Saccharopolyspora spinosa; works on contact and by ingestion and has translaminar activity. Registered for use as a foliar spray on asparagus, brassicas, corn, cucurbits, herbs, legumes, and bulb, fruiting, leafy, root, and tuber vegetables for control or suppression of caterpillars, leafminers, psyllids, thrips, and certain beetles. Labeled for suppression of cabbage root maggot in leafy brassicas. Also has 2(ee) label for control of spotted wing drosophila on fruiting vegetables. Toxic to bees for 3 hours following treatment. (Group 5, REI 4h)

Reaper* (abamectin): See Agri-Mek for more information.

Regent* (fipronil): A chloride channel antagonist that targets nerve and muscle tissue. Registered for in-furrow use on potatoes to control wireworms only. (Group 2B, REI 0h)

Requiem (Chenopodium ambrosioides extract): A contact insecticide and miticide derived from the herb Chenopodium ambrosioides; works on contact. Registered for use as a foliar spray on brassicas, bulbs, cucurbits, fruiting, leafy, root, tuber, and corm vegetables to control leafminers, thrips, and whiteflies. Low impact on beneficials. (No resistance classification, REI 4h)

Respect* (zeta-cypermethrin): See Mustang for more information.

ReTurn (oxamyl): See Vydate for more information.

Rimon (novaluron): An insect growth regulator that works through contact or via ingestion on immature stages to disrupt cuticle formation during molt, causing death. Best used on early stages, no activity against adult pests. Registered for use as a foliar spray on beans, cucurbits, fruiting vegetables, brassicas, sweet corn, potatoes, and sweet potatoes for control of a wide range of pests. Not for use in greenhouses, except on tomatoes. Low impact on beneficials. (Group 15, REI 12h)

Safari (dinotefuran): A systemic neonicotinoid that targets insect nerve and muscle tissue. Registered for use as a foliar spray on a variety of vegetable transplants grown in enclosed structures for control of aphids, leafminers, mealybugs, thrips, and whiteflies. Highly toxic to bees. (Group 4A, REI 12h)

Sanmite (pyridaben): An insecticide and miticide for use in greenhouse cucumbers and tomatoes. (Group 21A, REI 12h)

Scorpion (dinotefuran): See Venom for more information.

SeduceOG (spinosad): An insecticidal bait derived from the soil bacterium Saccharopolyspora spinosa; acts as a nerve and stomach poison. Attracts and kills insects feeding on or near the base of plants. Registered as a soil treatment on a variety of crops to control a wide range of pests. (Group 5, REI 4h)

Sefina (afidopyropen): See Versys. Labeled for use on cucurbits and other fruiting vegetables. See Versys for more information.

Sevin (carbaryl): A carbamate that targets nerve and muscle tissue primarily through contact activity. Registered for use as a foliar spray on asparagus, brassicas, cucurbits, legumes, roots, tubers, and fruiting and leafy vegetables to control a range of insect pests. For cutworms, granular formulation or liquid formulation may be used on some crops. Harmful to beneficials, highly toxic to bees, and extremely toxic to aquatic invertebrates. Note: long REI before detasseling corn. (Group 1A, REI 12h, 24h for sweet corn, 21 days before detasseling corn)

Shuttle O (acequinocyl): See Kanemite for more information.

Silencer* (lambda-cyhalothrin): See Warrior for more information.

Sivanto (flupyradifurone): A broad-spectrum insecticide in a new class of chemistries, the butenolides. Acropetally systemic, and translaminar. Labeled for foliar applications in brassicas, cucurbits, fruiting, leafy, legume, root, and tuberous and corm vegetables for control of aphids, leafhoppers, whitefly, and in some crops, Colorado potato beetle, squash bugs, and psyllids. Also labeled for soil applications in cucurbits, fruiting vegetables, and leafy vegetables for control of aphids, leafhoppers, and whitefly. (Group 4D, REI 4h)

Skyraider* (bifenthrin + imidacloprid): See Brigade and Admire for more information.

SluggoOG (iron phosphate): A snail and slug bait and molluscicide. Disrupts feeding immediately and causes mortality in 3-6 days. Registered for use as a soil treatment to be scattered on moist soil around the perimeter of fields or banded in rows. May also be used in and around greenhouses; scatter around perimeter of greenhouse, or in and around pots. Low-risk material exempt from tolerances on food commodities. (No resistance classification, REI 0h)

SluggoOG Plus (iron phosphate + spinosad): See Sluggo + Entrust for more information.

Sniper* (bifenthrin): See Brigade for more information.

Steed* (bifenthrin + zeta-cypermethrin): See Brigade and Mustang for more information.

Suffoil-XOG (mineral oil): A paraffinic oil insecticide, miticide, and fungicide. Kills eggs, larvae, and nymphs of insects and mites and adults of soft-bodied insects through suffocation. Registered for use as a foliar spray on a variety of crops to control a wide range of pests. Safe for use in greenhouses. (No resistance classification, REI 4h)

SurroundOG (kaolin): A naturally-derived clay protectant and insect repellent. Registered for use as a foliar spray on a variety of crops to repel certain beetles, leafhoppers, thrips, and other pests. (No resistance classification, REI 4h)

Swagger* (imidacloprid + binfenthrin): See Admire and Brigade for more information.

Talstar Nursery* (bifenthrin): For greenhouse herbs only. See Brigade for more information.

Talus (buprofezin): An insect growth regulator that disrupts insect cuticle formation during molting through contact, ingestion, and vapor activity. Suppresses oviposition of adults and reduces viability of eggs. Mortality takes 3-7 days. Registered as a foliar spray on greenhouse tomatoes to control leafhoppers, mealybugs, planthoppers, and whiteflies. Long residual (up to 28 days). (Group 16, REI 12h)

Tempest* (bifenthrin + imidacloprid): See Brigade and Admire for more information.

Tersus (pyrethrins): See Pyganic for more information.

Thimet* (phorate): An organophosphate that is taken up by plant roots and acts systemically to target insect nerve and muscle tissue. Registered as a soil treatment in beans, corn, and potatoes for control of a range of pests. Highly toxic to bees. (Group 1B, REI 48h)

Timectin* (abamectin): See Agri-Mek for more information. 

Tombstone* (beta-cyfluthrin): See Baythroid for more information.

Torac (tolfenpyrad): A mitochondrial electron transport inhibitor that acts on contact. Registered for use as a foliar spray on leafy vegetables to control leafhoppers, aphids, flea beetle, and thrips. Highly toxic to bees. (Group 21A insecticide, Group 39 fungicide, REI 12h)

Tracer (spinosad): For control of caterpillars, leafminers, thrips, and other pests on corn and soybeans only. See Entrust for more information.

Transform (sulfoxaflor): Sole member of a new resistance classification subgroup, active against sap-feeding pests. Labeled for use as a foliar spray on potatoes and root and tuber vegetables to control aphids, leafhoppers, potato psyllids, and whitefly, and on succulent and dry beans to control aphids and plant bugs. Can be used as a rotational tool. Highly toxic to bees. Note: After being cancelled in 2015, sulfoxaflor registrations have been reinstated by the EPA under limited-use restrictions. (Group 4c, REI 24h)

TriActOG (neem oil): For use on vegetable transplants. See Azatin for more information. 

TridentOG (Bacillus thuringiensis subsp. tenebrionis strain SA-10): A bacterium-derived larvicide, labeled for control of Colorado potato beetle on potatoes, tomatoes, and eggplant. Must be ingested to be effective, so thorough plant coverage is essential. Most effective on young larvae in the first or second instar, or up to 1/4" in length. Apply as soon as eggs begin to hatch. After ingestion, larvae will stop feeding within a few hours and die within 2-4 days. Use of an adjuvant may improve efficacy, but avoid mixing with silicone-based surfactants. Note: Due to issues with formulation and shipping, Trident is not currently available. (Group 11, REI 4h)

Trigard (cyromazine): An insect growth regulator that acts by ingestion. Registered for use as a foliar spray on beans, brassicas, bulbs, cucurbits, leafy greens, peppers, and tomatoes for control of leafminers. Also labeled for Colorado potato beetle control in potatoes and suppression in tomatoes. (Group 17, REI 12h)

TrilogyOG (clarified hydrophobic extract of neem oil): A broad-spectrum miticide and fungicide, containing oil extracted from seeds of the neem tree. Mite control depends on direct contact and requires thorough coverage. Registered as a foliar spray on a variety of crops for a range of pests. (No resistance classification, REI 4h) 

VenerateOG (Heat-killed Burkholderia spp.): A biological insecticide containing killed cells and fermentation solids of Burkholderia spp. Works by contact and ingestion to disrupt insect exoskeletons and interfere with molting. Registered for use as a foliar spray on most vegetables to control foliar feeding and plant-sucking pests. (No resistance classification, REI 4h)

Venom (dinotefuran): A neonicotinoid that targets insect nerve and muscle tissue. Acts by contact and ingestion. Becomes systemic when applied to soil, and has translaminar activity when applied to foliage. Registered for use as a foliar spray or soil treatment on cucurbits, fruiting vegetables, brassicas, leafy greens, and potatoes to control sucking and chewing insects. Highly toxic to bees. (Group 4A, REI 12h)

Verimark (cyantraniliprole): A systemic diamide that works by ingestion of treated plant material. Labeled for use in soil applications on brassicas, cucurbits, and fruiting, leafy, and tuberous and corm vegetables to control sucking and chewing insects, including caterpillars, aphids, flea beetles, leafminers, thrips, and cabbage maggot. Also labeled for control of seedcorn maggot in cucurbits. May also be used as a potato seed piece treatment. Highly toxic to bees. (Group 28, REI 4h)

Versys (afidopyropen): Chordotonal organ modulator that acts to stop feeding immediately. Labeled for use on brassica head and stem vegetables, leaf petiole vegetables, leafy vegetables, pome fruit, and stone fruit. (Group 9D, REI 12h)

Vetica (flubendiamide + buprofezin): Note: All flubendiamide registrations were canceled by the EPA in 2016. Growers may use up existing stock. See Belt and Talus for more information.

Voliam Flexi (chlorantraniliprole + thiamethoxam): See Coragen and Actara for more information on active ingredients in this product.

Vydate* (oxamyl): A systemic carbamate insecticide and nematicide that is taken up by plant roots and acts on contact or by ingestion to target nerve and muscle tissue. Registered for use as a foliar spray or soil treatment on carrots, some cucurbits, eggplant, peppers, tomatoes, and sweet potatoes for control of nematodes and several insect pests. Labeled for control of brown marmorated stink bug in pepper and tomato. Highly toxic to bees, and extremely toxic to birds, fish, and mammals. (Group 1A, REI 48h)

Warrior* (lambda-cyhalothrin): A broad-spectrum pyrethroid insecticide that targets nerve and muscle tissue. Registered for use as a foliar spray on brassicas, cucurbits, sweet corn, fruiting vegetables, legumes, lettuce, bulb onions, garlic, and tuberous and corm vegetables to control a range of pests. May be applied before, during, or after planting for cutworm control. Highly toxic to bees, and extremely toxic to aquatic organisms. (Group 3, REI 24h)

Wrangler (imidacloprid): See Admire for more information.

XenTariOG (Bacillus thuringiensis subsp. aizawai): A derivative of the bacterium Bacillus thuringiensis subsp. aizawai. Works via ingestion, stopping feeding within an hour and inducing mortality within 3 days. Registered for use in field or greenhouse as a foliar spray on most vegetables for the control of caterpillars. May be especially useful for control of diamondback moth larvae that are resistant to Bt kurstaki or other products. Toxic to green lacewing and predatory mite (Metaseiulus occidentalis) (Group 11, REI 4h)

Xpedient* (bifenthrin): See Capture for more information.

Zeal (etoxazole): A mite growth regulator that works as an ovicide and larvicide. Registered for use as a foliar spray on cucurbits, mint, eggplant, and peppers to control mites. (Group 10B, REI 12h)

Zoro* (abamectin): See Agri-Mek for more information.

Zylo (methoxyfenozide): See Intrepid for more information.

Zyrate (esfenvalerate): See Asana for more information.

Insecticides and Miticides by A.I. (Table 27)

Insecticides and Miticides by A.I. (Table 27) Evonne Gong

Pesticides listed in bold were used as examples; their labels and SDS were consulted for the data given in this table. This information may vary slightly for the other products listed. No preference is indicated by this distinction.

The symbol * indicates a federally restricted-use pesticide. Unmarked active ingredients may have state restrictions; always check a product's registration status in your state before using.

The symbol OG indicates a pesticide that has been listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production.

Mixtures are listed under all active ingredients and indicated with an (M). 

When tank mixing pesticides, mix in the proper order. The order is Wettable Powders (WP), Water Dispersible Granules (WDG), Flowables (F) (DF) (SC), Water-dispersible liquids (AS), Emulsifiable Concentrates (EC), and Solutions (S). Always follow the pesticide label when using adjuvants such as spreader stickers, surfactants, etc.

ACTIVE INGREDIENT

TRADE NAME(S) & FORMULATION(S)

SIGNAL WORD1

RESISTANCE GROUP (IRAC2 CODE)

DERMAL LD50
(mg/kg)

ORAL LD50
(mg/kg)

TOXICITY TO BEES

abamectin*

Abacus; Abamex; Agri-Mek SC; Athena (M); Clinch Ant Bait; Nufarm Abamectin 0.15EC; Reaper 0.15EC, ClearForm; Tide Timectin 0.15EC; Zoro Miticide/Insecticide

W

6

>2,000

310

H

acephate

Acephate 90 Prill, 90 WDG, 90 WSP; Acephate 97 UP; Orthene 97

C

1B

>2,000

688

H

acequinocyl

Kanemite 15SC; Shuttle O

C

20B

>2,000

>5,000

L

acetamiprid

Assail 30SG, 70WP

C

4A

>2,000

805

M

alpha-cypermethrin* Fastac EC D 3A >5,000 >210 - <1,050 H
afidopyropen Inscalis, Sefina, Versys C 9D >2,000 1,320-6,690 L

azadirachtin

Amazin Plus 1.2%MEOG; Aza-DirectOG; AzaGuardOGAzatin OOG, XL; Azatrol ECOG; Ecozin Plus 1.2%MEOG; Molt-XOG; Neemix 4.5OG; Ornazin 3%EC

C

un

>2,000

>5,000

L

Bacillus thuringiensis subsp. aizawi

XenTariOG

C

11

>2,000

>5,000

L

Bacillus thuringiensis subsp. isrealensis

Gnatrol WDGOG

C

11

>5,000

>5,000

L

Bacillus thuringiensis subsp. kurstaki

CoStarOG; DeliverOG; Dipel ES, Dipel DFOG; Javelin WGOG

C

11

>2,020

>5,000

L

Bacillus thuringiensis subsp. tenebrionis strain SA-10 TridentOG (currently off the market due to formulation and shipping issues) C N/A -- -- M

Beauveria bassiana

Botanigard ES, 22WP; Mycotrol ESO

C

M

--

--

L

beta-cyfluthrin*

Aztec 2.1G (M), 4.67G (M); Baythroid XL; Defcon 2.1G (M); Leverage 360 (M); Tombstone; Helios

W

3

>2,000

647

H

bifenazate

Acramite 50WS; Floramite SC

C

un

>5,000

>5,000

M

bifenthrin*

Athena (M); Bifenture EC, 10DF; Brigade 2EC, WSB; Brigadier (M); Capture LFR; Discipline 2EC; Empower 2 (M); Fanfare ES; Hero (M), EW (M); Match-Up (M); Skyraider (M); Sniper, Helios, LFR; Steed (M); Swagger (M, EPA rated D); Talstar Nursery; Tempest (M); Xpedient Plus

W

3A

nil

262

H

buprofezin

Talus 70DF; Vetica (M)

C

16

>2,000

>5,000

L

Burkholderia spp. (heat killed) Strain A396 and spent fermentation media Venerate XCOG C N/A >5,050 >5,000 M

capsicum oleoresin extract

Captiva (M)

C

N/A

>2,000

>5,000

L

carbaryl

Carbaryl 4L; Sevin XLR Plus, 4F

C

1A

>4,000

699

H

Chenopodium ambrosioides extract

Requiem EC

C

--

>2,020

>5,000

L

chlorantraniliprole

Besiege* (M); Coragen, Durivo (M); Voliam Flexi (M)

C

28

>5,000

>5,000

L

chlorfenaspyr

Pylon Miticide

C

13

>2,000

560

M

Chromobacterium subtsugae

GrandevoOG

C

--

>5,000

>5,000

M

cinnamon oil

Ecotrol G2OG (M)

C

N/A

--

--

L

clarified hydrophobic extract of neem oil

Triact 70OG; TrilogyOG

C

--

>2,000

>5,000

M

clothianidin

Belay, 50WDG

C

4A

>5,000

>3,900

H

clove oil

Ecotrol G2OG (M)

C

N/A

--

--

L

cryolite

Prokil Cryolite 96

C

un

--

--

L

cyantraniliprole

Exirel; Verimark

C

28

>5,000

>5,000

H

cyclaniliprole Harvanta C 28 >2,000 >2,000 H

cyflumetofen

Nealta Miticide

C

25

>5,000

>2,000

L

cyromazine

Trigard

C

17

>2,010

4,460

L

deltamethrin*

Delta Gold

D

3A

>2,000

42.9

H

diazinon*

Diazinon AG500, 50W, AG600 WBC

C

1B

>2,000

787

H

diflubenzuron*

Dimilin 25W

C

15

>20,000

>10,000

L

dimethoate

Dimate 4EC; Dimethoate 4EC, 400

W

1B

1,000

60

H

dinotefuran

Safari 20SG; Scorpion 35SL; Venom

C

4A

>2,000

>2,000

H

emamectin benzoate*

Proclaim

C

6

>2,000

1,516

H

esfenvalerate*

Asana XL; Zyrate (M)

W

3

>2,000

458

H

ethoprop*

Mocap 15G, EC, 15G Lock n Load

D

1B

166

15.9

H

etoxazole

Zeal, WDG

C

10B

>5,000

>5,000

L

fenpropathrin*

Danitol 2.4EC

W

3

>500 - <5,000

>50 - <500

H

fenpyroximate

Akari 5SC; Portal XLO

W

21A

>2,000

810

L

fipronil*

Regent 4SC

W

2B

382

336

H

flonicamid

Beleaf 50SG

C

9C

>2,000

>2,000

L

flupyradifurone Sivanto 200SL C 4D >2,000 >2,000 L

gamma-cyhalothrin*

Bolton (M); Cobalt (M); Consero (M); Declare

C

3A

>5,000

>2,250

H

garlic oil

Captiva (M)

C

N/A

>2,000

>5,000

L

geraniol Ecotrol PlusOG (M) C N/A -- -- M

imidacloprid

Admire Pro; Advise Four; Alias 4F; AmTide Imidacloprid 2F, 4F; Brigadier (M); Couraze 2F, 4; Leverage 360 (M); Macho 2.0FL, 4.0FL; Mallet 75WSP; Marathon 1% Granular, 60WP, II; Midash Forte; Montana 2F, 4F; Nuprid 2SC, 4F Max; Pasada 1.6F; Skyraider* (M); Swagger* (M, EPA rated D); Tempest* (M); Wrangler

C

4A

>2,000

4,143

H

indoxacarb

Avaunt

C

22

>5,000

687

H

insecticidal soap (potassium salts of fatty acids)

DES-XOG; M-PedeOG

W

M

--

--

L

iron phosphate

Sluggo: Slug and Snail BaitOG

C

N/A

>5,000

>5,000

L

Isaria fumosorosea Apopka Strain 97 (formerly Paecilomyces fumosoroseus)

PFR-97 20% WDGOG , PreferalOG

C

M

--

--

M

kaolin

Surround WPOG

C

N/A

--

>5,000

L

lambda-cyhalothrin*

Besiege (M); Cobalt Advanced (M); Endigo ZC (M); Grizzly Too; Lambda-cy EC; Lambda-T2; Silencer 1EC; Warrior II with Zeon

W

3A

>2,000

180

H

ledprona Calantha C 35 >5,050 >5,000 L

malathion

Fyfanon ULV AG; Malathion 57EC, 5, 5EC, 8F, 8 Aquamul

W

1B

>2,000

550

H

metaldehyde

Deadline M-Ps, Bullets, GTs

C

N/A

>5,050

>5,000

L

Metarhizium anisopliae Strain F52

Met52 EC

C

N/A

>5,000

--

L

methomyl*

Lannate LV, SP; Nudrin LV, SP

D

1A

>2,000

49

H

methoxyfenozide

Intrepid 2F

C

18

>2,000

>5,000

L

mineral (or paraffinic, or petroleum) oil

 

Damoil; Organic JMS Stylet OilOG, JMS Stylet Oil, Mite-E-Oil; Suffoil-XOG

C

M

>2,000

>5,000

L

neem oil

See clarified hydrophobic extract of neem oil

 

 

 

 

 

novaluron

Rimon 0.83EC

W

15

>2,000

>5,000

L

oxamyl*

Vydate L, C-LV

D

1A

>5,000

9

H

peppermint oil

Ecotrol PlusOG (M)

C

N/A

--

--

M

permethrin*

Ambush 25W; Arctic 3.2EC; Permethrin 3.2AG; Perm-up 3.2EC; Pounce 25WP, 1.5G

C

3A

>2,000

1,100

H

phorate*

Thimet 20G Lock n Load, 20G Smartbox, 20G EZ Load

D

1B

86

5

M

phosmet

Imidan 70W

W

1B

>2,000

258

H

pymetrozine

Fulfill

C

9B

>2,000

>5,000

L

pyrethrins

Evergreen EC 60-6 (M); Pyganic EC1.4OG, Pyganic EC5.0IIOG; Pyrethrum TR (M); Pyronyl Crop Spray (M); Tersus

C

3A

>2,000

>2,000

M

pyriproxyfen

Distance IGR; Esteem 0.86EC; Knack IGR

C

7D

>2,000

3,773

L

rosemary oil

Ecotrol PlusOG (M)

C

N/A

--

--

M

sodium tetraborohydrate

Prev-AM Ultra

W

8D

>2,000

>5,000

L

soybean oil

Captiva (M); Golden Pest Spray OilOG

C

N/A

L

spinetoram

Radiant SC

C

5

>5,000

<5,000

M

spinosad

Blackhawk; Consero* (M); EntrustOG; Entrust SCOG; GF-120 NaturalyteOG; SeduceOG; Tracer

C

5

>5,000

>5,000

M

spiromesifen

Oberon 2SC, 4SC

C

23

--

>2,000

M

spirotetramat

Kontos Greenhouse and Nursery; Movento

C

23

--

>2,000

M

sulfoxaflor Closer; Transform D 4C >5,000 >2,000 H

sulfur

Bonide Garden Dust; Microfine sulfurOG; Microthiol DisperssOG

C

M2

2,000

>2,000

L

tebufenozide

Confirm 2F

C

18

>5,000

>5,000

L

tebupirimfos*

Aztec 2.1G (M), 4.67G (M); Defcon 2.1G (M)

W

3A, 1B

>2,000

132

L

tefluthrin*

Force CS, 3G, 3G Smartbox

W

3A

2,000 – 5,000

174

H

terbufos*

Counter 20G Smartbox

D

1B

71

8

M

thiamethoxam

Actara 25WDG; Cruiser 5FS, Maxx Potato (M), Vibrance Quattro (M); Durivo (M); Endigo* ZC (M); Platinum, 75SG; Voliam Flexi (M)

C

4A

>2,000

>5,000

H

thyme oil

Ecotrol G2OG (M)

C

N/A

--

--

L

tolfenpyrad

Torac

W

21A

>2,000

83

H

zeta-cypermethrin*

Hero (M), EW (M); Holster, Mustang, MAXX; Respect EC; Stallion (M); Steed (M)

W

3A

>2,000

234

H

Signal Word C = Caution; W = Warning: D = Danger

Insecticide Resistance Action Committee

Weed Management

Weed Management Evonne Gong

For information on managing weeds in specific crops, use the search bar or see the appropriate crop section(s).

Weeds compete with crops for water, light, and nutrients thereby reducing crop yield and quality. Competitive effects of weeds are density dependent, with increasing weed density causing increasing crop yield loss. The magnitude of loss varies based on the crop and weed species present and the timing of competitive interactions. Carrots, beets, and alliums, for example, are small-seeded, slow to emerge, and are poorly competitive early in the growing season. Larger-seeded crops (e.g. pea, bean, and corn), tubers (potato), or transplanted crops start with a significant initial size advantage over germinating weeds. A first principle of weed management is to establish this size advantage, and then maintain it with early weeding or mulching to reduce the density of competition weeds. To this end, successful weed management requires good foundational agronomic and horticultural practices regarding seedbed preparation, fertility and moisture management, timing and density of planting, choice of variety, as well as necessary early management of insect pests and plant pathogens. Remember, in plant competition, “the big get bigger!”

Weed Biology and Ecology

Weed identification is now easier than ever, with apps like “Picture This” getting better every year. While apps still perform poorly in identifying grasses and weed seedlings, recognizing your mature weedy flora is a great place to start. Weeds of the Northeast by Uva, Neal, and DiTomaso is another useful reference for weed identification.

Weedy plant species often share certain traits or characteristics that contribute to their success as the early colonists of disturbed sites, which is after all, the ecological job or “niche” of a weed. Fundamental weedy traits include rapid growth, high amount of seed production, and most notably, seed/bud dormancy to ensure offspring germinate and attempt to grow over several future years—an impressive bet-hedging strategy. Weedy species are also known for their “plasticity”, in other words, genotypic flexibility whereby an individual may exhibit different morphology in response to its environment (e.g., bushy growth in full sun but erect growth in a dense crop). 

Annual plants complete their life cycle in one year: seeds germinate, seedlings grow to maturity, flower, and reproduce all within a single growing season. Winter annuals germinate in late summer or fall, overwinter, and set seed the following spring. Summer annuals germinate in spring or early summer and set seed before fall, often in response to shorter days. Timing of germination and thus emergence is affected by species-specific dormancy characteristics and environmental conditions including light quality (e.g., affecting phytochrome), temperature, moisture, gas exchange, nitrate, and many other factors. These in turn are dramatically affected by soil disturbance (tillage or cultivation). Thus, it should be no surprise that annual weeds dominate the weedy flora of vegetable farms that rely on soil disturbance for residue management, seedbed preparation, amendment incorporation, and weed control. 

Weed seedbanks vary widely across farms. The seedbank refers to weed seeds on the soil surface or buried in the soil. Generally, seedbanks are larger on organic farms compared to farms using herbicides. Larger seedbanks result in a higher density of weed seedlings, or greater “weed pressure” as described by some farmers. The “bank” metaphor is useful in thinking about management, specifically the aim to reduce “credits” to the bank, i.e., avoid or reduce weed seed rain, while encouraging “debits” or losses. A common misperception is that weed seeds last forever in the soil, so “why bother to manage the seedbank?” While it is true that a seed may occasionally last many years, perhaps decades, by far, most seeds germinate or die in the first year. In fact, many annual weed seeds have a half-life of less than one year. In other words, 50% of the seeds produced this season will be gone in less than a year. This is true for several important weeds in our region, including redroot pigweed, common lambsquarters, hairy galinsoga, yellow foxtail, and crabgrasses.

Vegetable farmers are fortunate in having many options for weed seedbank management. Consider a field that will be used for a sequence of short season crops like radishes or leafy greens. Shallow tillage for seedbed preparation in this case serves to encourage weed germination, the most important of seedbank debiting mechanisms. This way, crop harvest can be completed and residues incorporated before weeds mature, thus preempting seed rain. 

Emergence periodicity is a useful aspect of weed biology that can be used to optimize fallowing or stale seedbed events that aim to reduce the germinable weed seedbank. Shallow tillage breaks seasonal dormancy for species ready to germinate. Thus, if targeting summer annuals, shallow tillage in June or July will encourage germination, while winter annual species will remain in the seedbank. 

Perennial weeds can live for more than one year and while most produce seed, vegetative propagation by stolons, rhizomes, or roots is generally more important. Tillage operations often drag perennial weed fragments from sod headlands or farm roads into vegetable fields. Shallow tillage around field margins throughout the growing season can establish a fallow zone to avoid this dispersal from tillage.

Monitoring weeds is an important but often neglected part of a weed management plan. Weed maps of field areas are extremely helpful in planning weed control strategies. A weed map can illustrate problem areas so that growers can target specific problems in specific areas and help plan for future crop rotations. Over time, weed maps can show shifts in weed pressure and indicate the possible need for a strategy change. Maps can also highlight the importance of managing dispersal, e.g., avoiding tillage that drags quackgrass rhizomes from grass alleys into fields, or working around a weed patch to avoid tillage dispersal. 

Dispersal is critical to the success of weeds, but rarely a priority for management. It is widely thought that weed seeds are blowing in from neighbors, hitching rides from birds or mammals, or washing in with irrigation or surface waters. These are important dispersal mechanisms, but they are rare events, generally moving only a very small fraction of a batch of seeds. In fact, well over half of most seeds are dispersed right around the base of the mother plant, and most remaining seeds not much further. In a natural setting, these seeds would be very crowded, with intense competition among the weeds when a cohort germinates the following year. In a farmed system, however, tillage events serve to disperse the seeds, spreading them out to the benefit of the weed. These local dispersal factors drive the patch dynamics that will be evident in your weed maps, with dense areas where reproduction was high, lower density radiating from the patch where tillage moved seeds, and then many other locations where weeds may be absent. 
 

Physical Weed Management

Physical Weed Management Evonne Gong

Physical weed control refers to actions that remove or kill weed seedlings, aiming to reduce weed density and thus maximize crop yield and quality. In vegetable crops, this often includes hand weeding, which is effective but expensive. Hand weeding time/cost is dependent on weed density, so efforts to reduce the weed seedbank and increase the efficacy of weeding tools will often improve net returns. The availability and cost of labor are key considerations, although it is common to perform some hand weeding in almost all vegetable crops. When relying on hand labor, start weeding operations with wheel hoes that can cover a lot of area quickly no matter the weed density. Next move to long-handled hoes designed for weeding: notable favorites among veteran organic vegetable farmers include the Glaser stirrup hoe and the colinear hoe. Using tools to get as close to the crop row as possible will reduce the final hand weeding labor. When tools are used for weed removal, physical weed control is sometimes referred to as “mechanical weed control”, or simply “cultivation”.

Cultivation is an important component of weed control in vegetables. Efficacy or effectiveness, refers to the proportion or percentage of weeds that are killed. A central problem with cultivation is that efficacy is low (60% is common) and highly variable (some places in the field may have 95% efficacy, while another may have only 5%). To improve efficacy, there are several principles to keep in mind.

  1. Establish and then maintain the crops’ size advantage. Selectivity (which refers to killing weeds but not the crop) of cultivation tools are generally based on a size differential between the crop and weed.
  2. Cultivation is most critical early in the growing season. Weeds are most effectively cultivated shortly after they germinate, and crops are most sensitive to weed pressure during their early stages of growth.
  3. Carefully prepare the seedbed. Flat, firm, residue-free soil surface conditions will allow weeding tools to consistently function throughout the field. A light-weight field cultivator or soil conditioner with a rolling basket is often a good choice. While large-seeded or transplanted crops do not require a perfect seedbed for planting and stand establishment, later cultivation operations will benefit from these early season efforts to prepare a nice seedbed.
  4. Tools should be carefully adjusted, first in the shop, and then in the field after some testing. Row-crop tools should target the same number of rows that were planted, or a simple fraction of this. For example, if using a one-row seeder, plan to cultivate one row at a time. If planting two or four rows, use a two or four row cultivator. Seeding with a walk-behind seeder is generally not going to be suitable for later tractor-mounted cultivation tools.
  5. Tools should be adjusted to work as shallowly as possible to minimize movement of seeds in the seedbank and break seed dormancy. After carefully adjusting spacing, place a 3/4" thick board under the gauge wheel of parallel linkage units (depth-controlling units), and then drop tools to the floor and tighten. Mark lines on the shop floor indicating crop row spacing to allow precise adjustment relative to the row. Magnetic levels are handy to adjust top-linkage of three-point hitch tools, and a protractor can be used to check the angles of tools to either avoid soil movement or hill as desired.

Blind cultivation is performed after crops have been planted, over the top of them, so that both in-row and between-row areas are cultivated. To minimize crop damage, this should be done before the crop has emerged and/or once it is well rooted. Slightly deeper planting depths and slightly higher plant populations are recommended to compensate for some crop loss that may occur. Very tender crops such as leafy greens are not amenable to this technique, but a surprising array of crops are suitable for blind cultivation, including corn, cucurbits, and beets, depending on stage of growth and equipment used.

Tine harrows have multiple rows of flexible metal tines that cover the entire soil surface, wiggling slightly as they are pulled along, uprooting or dislodging very small weeds. They work best at relatively high speeds, and the wide span of the tool makes cultivation quick. They are rear-mounted and available in many widths. The tension on the tines can be adjusted on some units or by the pressure on the 3-point hitch on other units. Gauge wheels can be used to maintain uniform depth. Tine harrows work best in friable soils free of rocks, and when weather allows weeds to dry out on soil surface after uprooting.

Rotary hoes have many narrowly spaced metal wheels each with about 16 curved teeth that work the surface of the soil. Used within the first few weeks of planting vigorous crops like corn or beans, they destroy weeds that have just germinated. Ground-driven, spring-loaded wheels do little damage to the crop and work well at high speeds on dry, rock-free soils with little residue. They are rear mounted and available in many widths. The teeth, or spoons, lose their effectiveness if not sharp.

Between-row cultivation can be performed with varying degrees of aggressiveness, so that soil may or may not be pushed into the row to obtain some in-row weed control. Commonly used cultivation setups consist of a shank (either straight, C-, or S-shaped) attached to a toolbar, with a cultivating tool (shovel, sweep, knife, hilling disc, etc.) attached to the bottom. The more curve to the shank, the more it will vibrate and flex in the soil. Trip-shanks have a release mechanism that allows the shank to pop up when it hits a rock. Shanks can be arranged on multiple toolbars to offer complete coverage between multiple rows in beds. There are many kinds of tools that can be attached to the shanks, and these should be selected to disturb only as much soil as is needed to kill the weeds present. In general, one starts the season with smaller, shallower tools to kill small weeds when the crop is small; as the season goes on, if larger weeds are present, then more aggressive tools are needed. As the crop grows it is possible to more aggressively push soil into the row without causing damage. For example, shovels might be followed by sweeps and then hilling discs. Another strategy is to adjust the angle of cultivating tools such as hilling discs or rolling cultivators as the season goes on. Start by pulling soil away from the row when cultivating a young crop; that creates a small hill that can be pushed back into the row when the crop is a bit older to bury weeds.
In small and/or tender crops like leafy greens, shallow tools are needed that will not move soil into the row and cause damage. A side-knife (or beet-hoe) may be used to cultivate horizontally next to the crop, just below the surface.

Basket weeders are relatively high-speed, between-row cultivators good for control of small weeds in narrow rows when crop is small. The wire baskets work the soil surface and do not move soil into the row, but they don't work well in crusted or rocky soil. The front set of baskets are ground driven, and they turn the rear set of baskets a bit faster via a chain and gearing, causing scuffing of the soil. These are available in 2-6-row units that can be rear- or belly-mounted.

Finger weeders consist of steel cone wheels that are ground-driven by spike tines on the bottom, with rubber fingers on the perimeter. The rubber fingers work the soil just below the surface, uprooting small weeds located very close to the crop. Finger weeders work best for control of small weeds in dry, friable soil with few rocks or residues. Clay soils may stick to fingers.

Spring-hoe, torsion weeders, and spyder weeders are flexible blades and square metal stock that disturb soil around the base of plants, and ground-driven spyder wheels with staggered teeth in an uneven pattern that break clods and throws soil into row, or pull it away, depending on the angle. These can be toolbar-mounted, either under the belly or in the rear. They can be used together, separately, or in conjunction with other cultivators.

Rolling cultivators have gangs of soil-driven 'spider wheels' that mount independently on a toolbar. The angle that they work the soil, and thus their aggressiveness, is usually adjustable. The number of gangs grouped together determines cultivator width, and these are usually rear-mounted, but pairs of gangs may be belly-mounted to work a row or two. Soil can be thrown into row to bury small weeds or to form hills, depending on angle of the gangs. This is a relatively heavy, aggressive tool.

Reigi weeders require a rear operator who steers a pair of rotating horizontal wheels in and out of the crop row. The wheels are turned by a PTO-driven belt, and they have stiff tines on them that root out weeds. The wheels come in several sizes useful for various row spacings, and the units come in 1- or 2-row models. These are very effective for killing weeds in and next to the row in widely spaced crops like pumpkins, first-year strawberries, or sweet corn with a lot of skips.

Flame weeding, also known as thermal weeding or flame cultivation, exposes plants to brief periods of high temperature that causes the water in the plant tissue to expand rapidly, rupturing plant cells and leading to tissue damage. Plants are not burned or incinerated, but "blanched". They will not show symptoms of injury until several hours after exposure. Some weeds, such as purslane, can tolerate high temperature, and grasses with their growing points below ground are not controlled by flaming. When weeds are moist from rain or dew, more heat (i.e., a slower tractor or walking speed) will be necessary.

Flaming is ideal for stale seedbeds because it kills weeds without soil disturbance, which would bring up new weed seeds to germinate. For longer-lasting weed control, apply the final flaming as late as possible prior to crop emergence after seeding or just prior to transplanting. However, broadleaf weeds should be flamed at the three-leaf stage, before they grow too large for effective flame control.

Hand-held propane torches are commonly used to flame single rows at a time, but multi-row bed-flamers and tractor-mounted flamer kits are also available. Larger units require greater attention to safety during construction and operation. Safety is a big issue with flaming. Consult with a gas professional if constructing your own flaming unit. Do not mount propane tanks intended for stationary use onto tractors. Flame against the breeze and avoid areas with dry residues or dry hedgerows. Liability concerns may hinder the use of flaming.

Cultural Weed Management

Cultural Weed Management Evonne Gong

Plant competition is a foundation of weed management. Remember, “the big get bigger.” Large-seeded crops and transplants have an initial size advantage over weeds. Decreasing the space between crops will also increase soil shading. Overall, the more rapidly a crop can cover the soil ahead of weed emergence, the more competitive that crop will be. Choose high quality seed, calibrate equipment to ensure accurate seeding rates and depth, and where possible, supply resources selectively to the crop, e.g., apply fertilizers banded below/near the crop row, or through drip irrigation, instead of broadcasting.

Other cultural strategies that help to manage weeds include cover crops, mulches, fallowing, stale beds, crop rotation, and soil preparation.

Cover crops

Cover crops reduce overall weed populations in several ways.

  • Shallow tillage between short cycles of cover crop growth kills weed seedlings and encourages germination of a new “flush” of weeds that can be killed with the next disturbance. Encouraging weed seed germination, but not allowing further weed seed production reduces weed seeds in the soil seedbank over time.
  • While it is growing, a dense cover crop stand will suppress weed growth by shading the soil. A season-long cover crop can help suppress weeds that may have otherwise matured and set seed.
  • Cover crops can slow soil warming in the spring, helping to slow weed seed germination and reduce the soil seedbank over time.

Despite these benefits, perennial weeds can increase when perennial cover crops are in place for a longer period of time, e.g., one or more years of red clover.

Mulches

Mulches are often used to control weeds. Mulches can be organic (straw, hay, grass clippings, dead cover crops), inorganic (plastic), or degradable (bio- or photo-degradable plastics).

  • Organic mulches are effective if they are thick enough to keep weeds from emerging through them (usually at least 2-3"). Downsides of organic mulches are that they can be expensive, they reduce soil temperatures and slow soil warming, they can reduce nitrogen availability, and they can harbor animal pests. Cooler soil temperatures can be a problem in warm season crops. It is recommended that the mulch application be delayed enough to allow the soil to warm up sufficiently for the crop.
  • Black plastic mulches will warm soil and eliminate weed pressure. However, weeds emerging through the planting holes and between strips of plastic mulch can still reduce yields if not controlled. Infra-Red Transmitting (IRT) mulches are less effective than black plastic for controlling weeds, and clear mulches can enhance weed growth. Some growers plant cover crops between plastic mulch strips as "living mulch", but these cover crops can also compete with the crop. Killing the living mulch before the crop is planted, mowing the mulch on a regular basis, or using raised beds will help to reduce but not eliminate competition. See the section on Herbicides and Plastic Mulches for more information. A downside of black plastic mulch is that they generate a lot of plastic waste material, which can be difficult and expensive to dispose of.
  • Degradable plastic mulches are more expensive than plastic mulches and rip more easily, which exposes soil where weeds can germinate. They are also not approved for organic production. However, degradable plastics can be plowed into the soil after the growing season, reducing the need for plastic waste disposal.

Fallowing

Fallowing is not planting a field with the intention to reduce weed seed populations. Repeated shallow soil disturbance will encourage weeds to germinate while subsequent events kill seedlings before they go to seed. Over time this strategy will reduce the weed seedbank of a field and can help manage established perennial weeds.

Crop rotation

Crop rotation can be a tool for managing weeds. Weed species present tend to be most like the crop planted. Examples include grasses in corn, winter annuals with early-planted crops, and perennial weeds with perennial crops. Rotating crops among these groups will tend to disrupt this trend.

Proper soil preparation

Proper soil preparation can influence weed emergence. Soils which are rough and less firmly packed will yield fewer weeds than those that are more finely worked, more compacted, and more uniformly moist. However, as noted above, a well-prepared seedbed will help weeding tools function to their potential during later cultivation events.

Stale seedbed

Stale seedbed is the practice of preparing a field for planting and then lightly disturbing the soil on a regular basis to kill small weeds as they emerge, without bringing up new weed seeds from below the top few inches of soil. Tools that can be used for this practice include chain-drag, spring-tooth harrow, light-weight disc harrows, tine weeders, or flame weeders. Stale seedbeds can be used in the spring before a crop is sown, or in the summer after a spring crop but before a fall crop. A summer fallow works better on summer annual broadleaves that emerge later in the season. Perennial weeds may be weakened but not killed. See Stale Seedbed Technique for more information.

Stale Seedbed Technique

The stale seedbed approach involves preparing the soil as if for planting, without actually planting the crop. After soils are prepared, weed seeds in the upper 1-2" of the soil are encouraged to germinate through adequate soil moisture and temperature (with irrigation or row covers). Generally, this happens within 2 weeks. Weeds are then killed with Gramoxone, Roundup, Scythe, or flaming.

Killing emerged weeds with herbicides or flaming does not disturb the soil, and no new weed seeds will be brought close to the soil surface. After using the stale seedbed technique, care should be taken not to disturb the soil any more than is absolutely necessary during the seeding or transplanting process to minimize the amount of weed seeds that are brought up to the surface to germinate. Preemergence herbicides can be used after a stale seedbed to further reduce germination. Any cultivation performed after should be kept extremely shallow (3/4-1" maximum) so as not to reposition any additional weed seeds.

On sandy, loamy, or high organic matter soils, the soil should not crust and modern seeders should still work satisfactorily. On heavy clay soils, crusting could make this technique unusable.

Stale Seedbed Steps:

  • Prepare the soil as if you are about to seed or transplant. If a soil-incorporated herbicide is used, it must be applied and incorporated at this time. The soil should have good moisture (irrigate with 1/4" of water if necessary).
  • Wait as long as possible to allow weeds to germinate and emerge. Allow weed seedlings to grow to the third-leaf stage, or at least to the first true leaf.
  • If you're using transplants: flame the soil or make an application of Gramoxone, Scythe, Aim, or Roundup (if registered for the crop) to the soil surface before transplanting. Transplant the crop, without dragging any additional soil off the bed, and then apply any preemergence herbicide that you would normally use, to the soil surface.
  • If the crop will be direct-seeded: Gramoxone, Scythe, Aim, or Roundup (if registered for the crop) or flaming may be applied just before or just after seeding (see the label). After seeding, apply any preemergence herbicide that you would normally use to the soil surface. CAUTION: If the crop has already been seeded, be careful that the flaming process does not injure the crop seed or the emerging crop seedling.

Check the current herbicide label and recommendations by crop to determine if Gramoxone, Scythe, Aim, or Roundup is registered for use in that crop. Gramoxone, Scythe, Aim, and flaming will have minimal long-term effect on established perennial weeds. For cucumbers, melons, squash, pumpkin, peppers, and eggplant, Roundup must be applied at least 3 days prior to seeding or transplanting.

In cases where Roundup is registered, it can also be used for control of perennial weeds, such as quackgrass and dock, prior to soil preparation. After application, delay tillage for 3-5 days. There is no residual weed control. See the label for directions.

About Herbicides

About Herbicides Evonne Gong

Herbicides are chemicals designed to control weeds. The use of these materials must be exact for satisfactory results. Proper rate selection, timing of application, activation, and observance of all precautions on the label must be followed to obtain optimum performance. Each herbicide controls certain weed species or families. Therefore, knowledge of the weed species present in the field is essential for good weed control. Once the weeds are identified, select the proper herbicide.

Herbicides can be classified several different ways and understanding what the classifications mean can help you better select the most appropriate herbicide to use for different situations.

Herbicides can be pre-emergent or post-emergent.

  • Preemergence herbicides (PRE) are applied prior to the emergence of weeds. Some need to be incorporated into the soil with tillage (pre-plant incorporated) and others are applied to the soil surface and are sometimes incorporated with irrigation or rainfall (pre-soil-applied). In general, they work by preventing germinating weeds from growing, but some can also act on perennial plants that spread by rhizomes, tubers, and stolons. These herbicides prevent new weeds from emerging, but most will not impact weeds that are already emerged. 
  • Postemergence herbicides (POST) work on actively growing weeds. They can be absorbed by the leaves or roots of the plants, depending on the chemical.

Herbicides can be systemic or contact.

  • Systemic herbicides are absorbed by the plant and move through the plant to the site of action, where the herbicide kills the plant.
  • Contact herbicides only affect the plant tissue they come into contact with. It is especially important to achieve good coverage of weeds when using these herbicides.

Herbicides can be selective or non-selective.

  • Selective herbicides only work to kill certain species or types of plants. Selectivity is usually due to the physiology of the plant and the rate at which an herbicide is applied.
  • Non-selective herbicides kill or injure any plant they come into contact with (as long as the weed has not developed resistance to the herbicide). These types of herbicides are used as burn-down products in situations where it is desirable for all living plant material to be killed.

These different classifications are usually well-defined, but not necessarily always exclusive (e.g. a pre-emergent herbicide can also have some post-emergent activity). The different types of classifications interact together. For example, 2,4-D is a postemergent, systemic, selective herbicide meaning that you apply it to actively growing weeds. It is absorbed by the plant and travels to meristems, causing death by uncontrolled growth, and only affects broadleaf plants (not grasses). Paraquat is another postemergent herbicide, but it is a contact and non-selective herbicide meaning that it is applied to actively growing weeds and kills all plant tissue the spray touches but does not harm tissue that is not sprayed.

Adjuvants are added to a pesticide mixture to improve its effectiveness. They include surfactants, stickers, penetrants, and compatibility agents. Pesticide labels may list specific types of adjuvants that will maximize effectiveness of the pesticide. Be sure to use the proper category of adjuvant if the manufacturer makes a specific recommendation.

When adjuvants are recommended, it is because research has shown that their addition increases efficacy of the herbicide. If the label advocates the usage of an adjuvant, do not omit the adjuvant solely to save money. The most common adjuvants used with herbicides are nonionic surfactants (NIS) and crop oil concentrates (COC) which can consist of petroleum, vegetable, or methylated vegetable or seed oils. They increase penetration of the herbicide through the leaf cuticle.

Herbicides and Crop Rotation Restrictions

Some herbicides can have long-lasting activity. Many herbicides have crop rotation restrictions where they have been applied. For example, Devrinol has a 60-day plantback interval for leafy greens. Check the label of each product for details.

Toxicity of Herbicides

The toxicity of pesticides varies by the active ingredient, concentration of active ingredient, and the formulation of the product (e.g. liquid, powder, etc.). The toxicity of a pesticide is expressed in terms of oral (administered internally) and dermal (applied to the skin) LD50. LD50 is the dosage of poison that kills 50% of test animals (usually rats) with a single application of the pesticide product and is expressed as mg/kg of body weight. The lower the LD50 value, the more toxic the material.

The acute (short-term) toxicity of the formulated product is conveyed on label by a “signal word” stated on the front page. 

DANGER (most dangerous): Pesticide product is highly toxic by at least one route of exposure. It may be corrosive and cause irreversible damage to the skin or eyes. If the product is highly toxic if eaten, absorbed through the skin, or inhaled, then the word “POISON” must also be included in red letters.

WARNING: Pesticide product is moderately toxic if eaten, absorbed through the skin, inhaled, or it causes moderate eye or skin irritation.

CAUTION (least dangerous): Pesticide product is slightly toxic if eaten, absorbed through the skin, inhaled, or it causes slight eye or skin irritation.

General Principles for Safe Use

  • Know the herbicide. Read the label.
  • Check the output of sprayer frequently. See Pesticide Equipment Calibration.
  • Replace worn nozzles. It may be necessary to replace them several times a season if the sprayer is used constantly.
  • Rinse spray equipment immediately after use. Use one sprayer for herbicides and another for insecticides and fungicides.
  • For an overview of herbicide use restrictions, safety concerns, and other information see Tables 28 and 29.
  • For an overview of crops labeled for each herbicide, see Table 30.
  • For an overview of weeds listed as controlled on each label, see Table 31.
  • For limitations and special requirements of the herbicide, refer to the product label (or supplemental label).

Rate Selection

Always check the label to determine the proper rate to apply. For most soil-applied herbicides, knowledge of the type of soil and the percentage organic matter usually determines the rate. Generally, the more clay and/or organic matter present in the soil, the higher the herbicide rate necessary for good weed control. For postemergence herbicides, the type of weed, as well as its size, will usually determine the rate.

Incorporation of Herbicides

Some herbicides must be incorporated into the soil to be effective. Herbicides are incorporated because they are volatile and evaporate into the air if left on the soil surface or they will decompose when exposed to sunlight. Herbicides differ in their incorporation requirements; check the product label for the manufacturer's requirements.

Herbicide Sprayer Systems

  • Select a sprayer and pump that can deliver a volume of 20-50 gallons per acre. Most herbicides are applied at rates of 20-40 gallons of water per acre. Pressures of 20-40 psi at the nozzle are recommended for most herbicides. Higher pressures result in finer droplets and increase the chance for more drift. Lower pressures sometimes cause uneven spray patterns.
  • Use 50-mesh screened filters for nozzles and suction lines.
  • Select 80-73º flat fan nozzles. Because of wear, brass tips used exclusively for applying wettable powders should not be used on more than 30 acres before being replaced. Use stainless steel or hardened stainless steel tips for longer wear. Stainless steel nozzle tips are more than twice the cost of brass tips but last about 20 times longer. Hardened stainless steel tips are only slightly more expensive than stainless steel tips but last three times longer. Ceramic nozzles are the most durable.
  • Calibrate sprayers frequently and check for wear, especially when wettable powders have been used. See Pesticide Equipment Calibration.

Resistance Management

Each herbicide has a mode of action—how and where the chemicals in an herbicide work to kill a target weed. However, through natural random genetic mutations, weeds can develop resistance to a mode of action. Resistance in a weed makes it less sensitive to an herbicide. Since mutations that lead to resistance are genetic, they are inheritable. When an herbicide is used, weeds that are susceptible to an herbicide will be killed, but any with the genetic mutation that makes them less sensitive will survive. These then reproduce and pass on the genes that let them survive the herbicide exposure to their offspring. If the same herbicide is used repeatedly in the same field, over time the predominant genetic form of that weed in that field will be resistant to that herbicide. A higher rate of the same or a similar chemical from the same group usually will not control the weed and these weeds can become extremely difficult to manage.

There are many techniques that can help delay the onset of resistance.

  • Integrate cultural, mechanical, and physical weed control techniques to reduce reliance on chemical tools.
  • Scout fields so that you are aware of what is not controlled.
  • Take steps to control escaped weeds, especially preventing seed set.
  • Good rate selection, spray coverage, and herbicide activation helps do the job right the first time and avoids unnecessary repeat applications. Use the proper size nozzles, the correct angle or orientation, and the right amount of water per acre.
  • Time postemergence applications so that the weeds are at the right stage of growth.

One of the most important ways to slow resistance development and extend the useful life of an effective product is to rotate the use of products with different modes of action. This can be done in several ways:

  • Rotate the type of herbicide used on fields where the same crop is grown year after year.
  • Rotate the crops grown on a field so that different herbicides are used on that field.

Even if herbicides have different active ingredients, they can share the same mode of action. It is very difficult to know which herbicides share a mode of action. To help growers effectively rotate herbicides, international groups have assigned group numbers to herbicides based on the mode of action. The Herbicide Resistance Action Committee (HRAC) and The Weed Science Society of America (WSSA) have developed a harmonized classification system of herbicides using numbers to designate herbicide categories. Herbicides with the same number have the same mode of action. Most labels now come with this group number assigned to them (some have not been updated to the HRAC/WSSA number, but will in the future).

When selecting herbicides to rotate between for resistance management, use the group number as your guide and NOT the product name or active ingredient. These resistance groupings are listed in Table 28.

NOTE: The group number is specific for each type of pesticide (insecticides, herbicides, and fungicides). For example, there is no problem with using material from the herbicide Group 1 and an insecticide or fungicide from Group 1.

The most common weed resistance issue that we have in New England is common lambsquarters that is resistant to atrazine.

Groundwater Concerns

The following herbicides have the potential to impact groundwater due to their chemical characteristics and toxicological profile and have been discussed in the crops sections. Check with your state for restrictions on their use in sensitive areas. For example, Massachusetts has Zone II designations and regulations pertaining to the use of these herbicides in those areas.

  • Atrazine (Aatrex)
  • Bentazon (Basagran)
  • Chlorthal-Dimethyl (Dacthal, DCPA)
  • Dimethanamid (Outlook)
  • Diuron (Karmex)
  • Fluthiacet-methyl (Cadet)
  • Metolachlor (Dual Magnum)
  • Metribuzin
  • Pronamide (Kerb)
  • Simazine (Princep)

Herbicides and Plastic Mulches

With the increased use of plasticulture for the production of various vegetable crops, it is very important to keep in mind a few points for proper weed management. Here are some tips:

If soil is fumigated under plastic strips (e.g. Vapam), there is no need for an herbicide under the plastic. Herbicides can be used under the plastic but are often unnecessary under black plastic unless there is nutsedge or excessive weed pressure. If you use clear or white plastic without soil fumigation, then you need an herbicide under the plastic mulch. To get the best results, take the following steps for herbicide application:

  1. Prepare a pressed bed.
  2. Apply the herbicide to the bed surface.
  3. Activate the herbicide with rainfall or overhead irrigation (at least 1/2"); if the herbicide needs to be mechanically incorporated, do so and repress the bed.
  4. Apply the plastic mulch.
  5. If weeds are present between the plastic strips before planting, use a banded application of Gramoxone plus surfactant, or Roundup (if registered for stale bed use) to kill all existing vegetation. Depending on the level of weed vigor, a second application of Gramoxone plus surfactant may be needed before planting. Do not broadcast apply these herbicides to the surface of the mulch.
  6. For weed control between the plastic beds after planting, use a registered preemergence herbicide for that crop. Do not use nonregistered herbicides between beds as the crop roots will grow in that zone and, in many cases, the crop will be damaged or killed. Do not spray the surface of the plastic with any preemergence herbicides! During a rainfall the excess herbicide will wash into the holes where the crop was planted and will greatly concentrate the herbicide. Thus, the crop will be damaged or killed. When banded applications of herbicides are used, remember to adjust the rate of the herbicide downward to conform to the actual ground area being sprayed (with 30" beds and 30" areas between strips, only half the normal amount of herbicide would be required per acre since only half the amount of soil area per acre is actually being sprayed).

Notes:

  • Herbicide use under row covers can be dangerous, as some may volatilize and cause crop injury when used under plastic mulches or row covers. Some herbicides are prohibited from use under row covers. Be sure to observe any cautions on the product label.
  • Generally, ventilated covers are safer than solid covers or hot caps, from an herbicide injury standpoint. This is especially true with an herbicide that is moderately or highly volatile.
  • Wherever possible, try it on a small scale before you apply it on a large scale.
  • Use caution when spraying Gramoxone with a backpack or hand-held sprayer. Wear rubber boots, gloves, and a mask or respirator. Avoid skin contact with the spray. If contact occurs, immediately rinse the area with water or rub soil on your skin. Soil will help soak up and bind the chemical, preventing its absorption into the skin. Spray when the wind is calm to avoid spray drift. Also, always use a surfactant and plenty of water with Gramoxone for good control.
  • Vapam is not recommended for use in the spring if the plastic is to remain in place. Under the cool soil conditions at this time of year, the soil will not aerate properly and the crop will be damaged. In plasticulture, these materials are best used if the plastic is applied the fall before planting. With all fumigants, be sure to space the injection shanks correctly. The label recommends a 6" spacing with Vapam.
  • Backpack sprayers or modified boom sprayers are often used for herbicide applications in plasticulture systems. Be sure to calibrate them properly and maintain a constant pressure using a pressure gauge, especially on hand-pumped models. Maintaining a constant speed or walking pace is also necessary. Three miles per hour is a good speed (23 seconds per 100').
About Herbicides

Herbicides Alphabetically Listed by Trade Name (Table 28)

Herbicides Alphabetically Listed by Trade Name (Table 28) Evonne Gong
TRADE NAME1 ACTIVE INGREDIENT HRAC2 GROUP REI (hours) ROTATION RESTRICTIONS PRE-SA3 PPI4 POST5 WEEDS & CROPS LABELED
2,4-D Amine 4 2, 4-D 4 48 no no no yes Annual and perennial broadleaf weeds in asparagus and corn
Aatrex 4L* atrazine 5 12 yes yes yes yes Some annual grass and broadleaf weeds in corn
Accent Q nicosulfuron 2 4 yes no no yes Some grasses (including rhizotomous Johnsongrass) and some broadleaf weeds in corn
Aim EC carfentrazone-ethyl 14 12 yes no no yes Broadleaf weeds in corn and cucurbits
Aquesta 4F sulfentrazone 14 12 yes yes yes yes Mostly annual broadleaf weeds and yellow nutsedge in asparagus, beans, brassicas, cucurbits, eggplant, okra, peas, peppers, rhubarb, tomatoes, and turnip
Assure II quizalofop 1 12 yes no no yes Annual and perennial grasses in legumes
Basagran 5L bentazon 6 48 no no no yes Yellow nutsedge (high rate) and select broadleaf weeds in legumes and sweet corn
Broclean bromoxynil 24 24 or 48  no no no yes Broadleaf weeds in bulb crops
Cadet fluthiacet-methyl 14 12 no no no yes Broadleaf weeds in corn (processing sweet corn only)
Callisto mesotrione 27 12 yes yes no yes Yellow nutsedge suppression and broadleaf weeds in corn and asparagus
Caparol 4L prometryn 5 24 or 48  yes yes no yes Some annual grasses and annual broadleaf weeds in carrots, celery, and parsley
Casoron 4G dichlobenil 29 24 yes yes yes no Some annual and perennial grass and broadleaf weeds and yellow nutsedge in rhubarb
Chateau EZ flumioxazin 14 12 yes yes no yes Grasses and many annual and perennial broadleaf weeds in asparagus, legumes, garlic, artichoke, and peppers
Clarity dicamba 4 24 no no no yes Annual, perennial, and biennial broadleaf weeds in asparagus
Clean Slate clopyralid 4 12 yes no no yes Many broadleaf weeds in asparagus, beets, corn, spinach, and turnips
Command 3ME clomazone 13 12 yes yes no no Annual grasses and some broadleaf weeds in pumpkins and peppers
Curbit ethalfluralin 3 24 yes yes no no Many annual grasses and broadleaf weeds in cucurbits
Dacthal Flowable herbicide DCPA EPA issued an emergency order on August 6, 2024 prohibiting all use, distribution, and sale of this product
Devrionol 2-XT napropamide 0 24 yes yes yes no Many grasses and some broadleaf weeds in asparagus, brassicas, and solanaceous crops
Dual Magnum** s-metolachlor 15 24 yes yes yes no Annual grasses, yellow nutsedge, and some broadleaf weeds in corn, potato, pumpkin, and tomato. **Dual Magnum has an indemnified label for use in some crop due to potential for crop injury. Users must agree to a waiver of liability through the Syngenta website to access the labels for these uses.
Eptam EPTC 15 12 no yes yes yes Annual and some perennial grasses, yellow nutsedge, and some broadleaf weeds in beans and potatoes
Evik DF ametryn 5 12 yes no no yes Many annual grass and broadleaf weeds in corn
Fusilade DX fluazifop-p-butyl 1 12 yes no no yes Many grasses in carrots, onions, spinach, and asparagus
Goal 2XL oxyfluorfen 14 24 or 48  yes yes no yes Some grasses and some broadleaf weeds in onions and brassicas
Gramoxone SL 3.0* paraquat 22 12 or 24 no no no yes Non-selective control of annual weeds and suppression of perennial weeds. May be fatal if swallowed or inhaled. Must complete an EPA-approved training every three years (list this at bottom of table).
Impact topramezone 27 12 yes no no yes Some grasses and many broadleaf weeds in corn
Kerb 50-W* pronamide 3 24 yes no yes no Some grass and broadleaf weeds in lettuce
Laudis tembotrione 27 12 yes no no yes Some grasses and many broadleaf weeds in corn
Lorox DF linuron 5 24 or 192 yes yes no yes Grasses and broadleaf weeds in carrots and parsely (has different pre- and post- emergence efficacy)
Matrix SG rimsulfuron 2 4 yes yes yes yes Grasses, yellow nutsedge, and broadleaf weeds in potato
Metribuzin metribuzin 5 12 yes no yes yes Grasses and broadleaf weeds in potatoes and tomatoes
Outlook dimethenamid 15 12 yes yes yes no Many annual grasses, yellow nutsedge, and annual broadleaf weeds in beans, corn, and root vegetables
Poast sethoxydim 1 12 no no no yes Annual and perennial grasses in most vegetables
Prefar 4-E bensulide 0 12 yes yes yes no Annual grasses in many vegetable crops
Princep 4L simazine 5 12 or 48 no yes no no Annual grass and broadleaf weeds in corn
Prowl H2O pendimethalin 3 24 yes yes yes no Annual grasses and some broadleaf weeds in asparagus, corn, peppers, potatoes, garlic, and onions
Quinstar 4L quinclorac 4 12 yes no no yes Some annual and difficult perennial grasses and broadleaf weeds including bindweed and Canada thistle in asparagus and rhubarb
Raptor imazamox 2 4 no no no yes Some grasses, yellow nutsedge suppression, and many broadleaf weeds in legumes
Reflex fomesafen 14 24 yes yes no yes Some grasses and many broadleaf weeds in beans and potatoes. Can only be used every other year.
Reglone diquat 22 24 no no no yes Non-selective control of small annual weeds and suppression of perennial weeds
Ro-Neet cycloate 15 48 no no yes no Some annual and perennial grasses, yellow nutsedge, and broadleaf weeds in beets and spinach
Roundup PowerMax 3 glyphosate 9 4 no no no yes Non-selective. Absorbed by the foliage of all weeds and translocated into the plant. Many formulations are available.
Sandea halosulfuron-methyl 2 12 yes yes no yes Yellow nutsedge and broadleaf weeds in asparagus, beans, corn, cucurbits, and fruiting vegetables
Scythe pelargonic acid 0 12 no no no yes Non-selective control of small annual weeds and suppression of perennial weeds
Select Max clethodim 1 24 yes no no yes Grasses in many vegetable crops
Sharpen saflufenacil 14 12 yes yes yes yes Broadleaf weeds in corn (not fresh market sweet corn) and legume harvest aid
Shield EX tolpyralate 27 12 yes no no yes Some grass and broadleaf weeds in corn
Simazine 90 WDG simazine 5 12 no yes no no Many annual grass and some broadleaf weeds in corn
Sinbar WDG terbacil 5 12 yes yes no yes Some grass, yellow nutsedge (high rate), and broadleaf weeds in asparagus
Solicam DF norflurazon 12 12 yes no yes no Grasses, yellow nutsedge suppression, and many broadleaf weeds in asparagus
Sonalan HFP ethalfluralin 3 24 yes yes no no Many annual grasses and broadleaf weeds in beans and potatoes
Stinger clopyralid 4 12 yes no no yes Many broadleaf weeds in beets, corn, spinach, and turnips
Surpass EC acetochlor 15 12 yes yes yes no Some annual broadleaf and grass weeds in corn
Treflan HFP trifluralin 3 12 yes no yes no Many annual grasses and some broadleaf weeds in many vegetables
Valor EZ flumioxazin 14 12 yes yes no yes Grasses and many annual and perennial broadleaf weeds in sweet potato
Zidua pyroxasulfone 15 12 yes yes yes no Annual grass, yellow nutsedge suppression, and some broadleaf weeds in corn

1Trade Name - Example herbicide trade name for the active ingredient. There may be several formulations of the same active ingredient with different trade names. Inclusion in this guide is not an endorsement of the product.

2HRAC - Herbicide Resistance Action Committee resistance management numbers.

3Pre-SA - This herbicide can be applied to the soil before weeds have emerged.

4PPI - This herbicide can be applied before weeds have emerged and incorporated into the soil.

5Post - This herbicide can be applied after weeds have emerged.

Herbicides Alphabetically Listed by A.I. (Table 29)

Herbicides Alphabetically Listed by A.I. (Table 29) Evonne Gong
ACTIVE INGREDIENT EXAMPLE TRADE NAME ADDITIONAL TRADE NAME(S) SIGNAL WORD1 RESISTANCE GROUP (HRAC2 CODE) DERMAL LD503
(mg/kg)
ORAL LD504
(mg/kg)
RESPIRATOR REQUIRED?
2, 4-D 2,4-D Amine 4   D 4 >5050 1340 no
acetochlor Surpass EC Breakfree NXT, Cadence, Cadence NXT, Confidence, Fearless, GCS Acetochlor 7EC, Harness, Surpass NXT, TopNotch, Volley NXT W 15 >2240 (similar material) 1415
(similar material)
no
ametryn Evik DF   C 5 >2020 4494 yes
atrazine Aatrex 4L*   C 5 >5050 >5000 no
bensulide Prefar 4-E   C 0 >2000 960 no
bentazon Basagran 5L Bastante D 6 >2000 1260 no
bromoxynil Broclean Moxy 2E, Palouse C 24 >2 238 no
carfentrazone-ethyl Aim EC Antik EC, Longbow EC C 14 >4000 4077 no
clethodim Select Max Arrow 2 EC, Ceridian 2 EC, Cleanse 2EC, Clethodim 2E, Dakota, Intensity Post-Emergence Grass, Intensity One Post-Emergence Grass, Shadow, Shadow 3EC, Tide USA Clethodim 2EC, Trizenta 3EC, Trizenta, Volunteer, Willowood Clethodim 2EC C 1 >5000 >5000 no
clomazone Command 3ME Clomate 3ME C 13 >5000 >5000 no
clopyralid Stinger, Clean Slate GCS Clopy 360SL, Spur, Stigmata C 4 >5000 >5000 no
cycloate Ro-Neet   C 15 >5000 3129 yes
DCPA Dacthal Flowable EPA issued an emergency order on August 6, 2024 prohibiting all use, distribution, and sale of this product
dicamba Clarity BL1, Clash Selective, Dicamba 4, Rifle, Sterling Blue, Strut, Topeka, WC-DCB C 4 >2000 >2000 no
dichlobenil Casoron 4G   C 29 slightly irritating >5000 yes
dimethenamid Outlook   W 15 >5000 695 yes
diquat Reglone Aceto Diquat 2L AG, Capone Desiccant, Nufarm Diquat 2 L, Nufarm Diquat SPC 2 L, Verdure-X C 22 >5050 886 no
EPTC Eptam   W 15 2750 1325 yes
ethalfluralin Curbit, Sonalan HFP   D 3 >5 mL/kg 3267 no
fluazifop-p-butyl Fusilade DX Stockade  C 1 >2000 >5000 yes
flumioxazin Chateau EZ, Valor SX Chateau SW, Flumi 51 WDG, Flumi SC , Flumi SX, Flumioxazin 51% WDG, Maxunitech Flumi SC Ag, Outflank, Panther SC, Tuscany, Tuscany SC C 14 >5000 >5000 yes
fluthiacet-methyl Cadet   W 14 >2020 2537 no
fomesafen Reflex Forsyte 1.88 SL, Ringside, Top Gun Flex, Top Gun, Willowood Fomesafen 1.88 SL D 14 >2000 >982 no
glyphosate Roundup PowerMax 3 Abundit Edge, Buccaneer 5 Extra, Buccaneer Plus, Bullzeye HL-K, Cornerstone K, Cornerstone 5 Plus, Cornerstone Plus, Credit 41 Extra, Credit K6, Credit Xtreme, CropSmart Glyphosate 41% Extra, Duplicator 6, Duramax, Durango DMA, Four Power Plus, Gly Star Original, Gly Star Plus, Glyphogan, Glyphogan Plus, Glyphosate 4 Plus, Honcho K6, Imitator DA, Mad Dog, Mad Dog 5.4, Mad Dog K6, Mad Dog Plus, Makaze, Roundup PowerMAX, Roundup WeatherMAX, Shar-Max Glyphosate 41% SL, Tomahawk 4, Tomahawk 5, Willowood Glypho 5, Willowood Glypho 6 C 9 5000 5000 no
halosulfuron-methyl Sandea Halomax 75, Permit, Profine 75, Stadia C 2 >5000 1287 no
imazamox Raptor Beyond Xtra  C 2 >4000 >5000 no
linuron Lorox DF Linex 4L Agricultural  C 5 >2000 3489 no
mesotrione Callisto Argos, Atticus Cavallo 4 SC, BL4, Explorer, Mesotrione 4SC, MesoTryOne 4L, Motif , Seeker 4SC, Seeker, Sotrion, Willowood Mesotrione 4SC C 27 >5000 >5000 no
metribuzin Metribuzin Glory, Glory 4L, Glory FDF, Metricor 4F, Metricor DF, Me-Try-Buzin 4L, Me-Try-Buzin 75DF, Rancor 4 F, Rancor 75 DF, TriCor 4F, TriCor DF C 5 >2000 2365 no
napropamide Devrionol 2-XT Devrinol DF-XT C 0 >2000 >2000 no
nicosulfuron Accent Q Primero C 2 >5000 >5000 no
norflurazon Solicam DF   C 12 >2000 1140 no
oxyfluorfen Goal 2XL Collide, Galigan 2E, GoalTender, ScrollOVR, Scroll 2 XL, Willowood OxyFlo 2EC W 14 >5000 3129 no
paraquat Gramoxone SL 3.0* Axill Solutions Paraquat 3SL*, Gramoxone SL 2.0*, Helmquat 3SL*, Paraquat 43.2% SL*, Paraquat Concentrate*, Parazone 3SL*, Quik-Quat*, Willowood Paraquat 3SL* D (Poison) 22 1990 172.81 yes
pelargonic acid Scythe   W 0 >2000 >5000 no
pendimethalin Prowl H2O AquaPen 3.8, Framework 3.3 EC Hebicide, Pin-Dee 3.3 EC, Prowl 3.3 EC, Satellite Flex, Satellite HydroCap, Stealth C 3 >5000 >2000 no
prometryn Caparol 4L   C 5 >5000 >5000 yes
pronamide Kerb 50-W* Kerb SC C 3 >2000 (similar material) >5000 (similar material) no
pyroxasulfone Zidua Zidua SC C 15 >2000 >2000 yes
quinclorac Quinstar 4L   C 4 >5000 5000 no
quizalofop Assure II FirstAct, Targa D 1 >2000 (similar material) 5900 (similar material) no
rimsulfuron Matrix SG DuPont Matrix SG, Grapple, Hinge, Tetris SG, Tide Rimsulfuron 25WG C 2 >2000 >5000 no
saflufenacil Sharpen   C 14 >5000 >2000 no
sethoxydim Poast   W 1 >5000 5000 no
simazine Simazine 90 WDG, Princep 4L Simazine 4L, Simazine 4L Flowable, Simazine 90DF, Sim-Trol 4l Simazine Flowable, Sim-Trol 90DF Simazine Dry Flowable  C 5 >2000 >5000 yes
s-metolachlor Dual Magnum** Brawl II, Charger MAX, Cinch C 15 >2000 3425 no
sulfentrazone Aquesta 4F Maxunitech Sulfentrazone 4 SC, Passage, Shutdown, Spartan 4F, Sulfentrazone 4L, Sulfin 4SC, Zeus XC, Zone 4F C 14 >2000 300 - 2000 no
tembotrione Laudis   C 27 >5000 1750 no
terbacil Sinbar WDG   C 5 >5000 >5000 no
tolpyralate Shield EX   C 27 >2000 >2000 no
topramezone Impact Armezon  C 27 >2000 >2000 no
trifluralin TreflanHFP Treflan TR-10 Granular, Trifluralin 10G, Trifluralin 4EC, Trifluralin HF, Triflurex HFP, Trust C 3 >2000 >4013 no

1Signal Word - (C) Caution is least dangerous, (W) Warning is intermediate, (D) Danger is most dangerous

2HRAC - Herbicide Resistance Action Committee number

3Dermal LD50 - The lethal dermal dose of the herbicide for 50% of a test population, usually of rats

4Oral LD50 - The lethal oral dose of the herbicide for 50% of a test population, usually of rats

Crops Labeled for Each Herbicide Trade Name (Table 30)

Crops Labeled for Each Herbicide Trade Name (Table 30) Evonne Gong
TRADE NAME
ACTIVE INGREDIENT
Asparagus
Basil
Beans
Beet/Chard
Brassicas
Carrot Parsnip
Celery
Corn (Pop)
Corn (Sweet)
Cucurbits
Eggplant
Garlic
Globe Artichoke
Leek
Lettuce Endive
Okra
Onions
Parsley Cilantro
Peas, Green
Peppers
Potatoes
Pumpkins
Radish
Rhubarb
Rutabaga, Turnip
Spinach
Sweet Potato
Tomatoes
2,4-D Amine 4 2, 4-D R             R R                                      
Aatrex 4L* atrazine               R R                                      
Accent Q nicosulfuron               R R                                      
Aim EC carfentrazone-ethyl R R R R R R R R R R R R R R R R R R R R R R R R R R R R
Aquesta 4F sulfentrazone R   R   R         R R         R     R R       R R     R
Assure II quizalofop     R                               R                  
Basagran 5L bentazon     R         R R                   R                  
Broclean bromoxynil                       R         R                      
Cadet fluthiacet-methyl               R R                                      
Callisto mesotrione R             R R             R               R        
Caparol 4L prometryn           R R                 R   R           R        
Casoron 4G dichlobenil                                               R        
Chateau EZ flumioxazin R   R                 R R             R                
Clarity dicamba R                                                      
Clean Slate clopyralid R     R       R R                               R R    
Command 3ME clomazone R R R   R         R               R R R   R   R     R  
Curbit ethalfluralin                   R                       R            
Dacthal Flowable DCPA       EPA issued an emergency order on August 6, 2024 prohibiting all use, distribution, and sale of this product.
Devrionol 2-XT napropamide R R     R           R                 R             R R
Dual Magnum s-metolachlor R**   R R** R** R**   R R R**   R**         R**   R R** R R   R   R**   R
Eptam EPTC     R                                   R              
Evik DF ametryn               R                                        
Fusilade DX fluazifop-p-butyl R   R     R           R     R   R             R     R  
Goal 2XL oxyfluorfen         R             R R       R                      
Gramoxone SL 3.0* paraquat R   R   R R   R R R R R R   R R R   R R R R   R R   R R
Impact topramezone               R R                                      
Kerb 50-W* pronamide                             R                          
Laudis tembotrione               R R                                      
Lorox DF linuron R   R     R R                     R R   R     R        
Matrix SG rimsulfuron                                         R             R
Metribuzin metribuzin R         R                         R   R             R
Outlook dimethenamid     R R       R R     R   R     R       R   R   R   R  
Poast sethoxydim R   R R R R R R R R R R R R R R R R   R R R R R R R   R
Prefar 4-E bensulide         R   R     R R R     R   R R   R   R            
Princep 4L simazine               R R                                      
Prowl H2O pendimethalin R   R   R R R R R   R R R R     R   R R R             R
Raptor imazamox     R                               R                  
Reflex fomesafen     R                                   R              
Reglone diquat R                       R               R              
Ro-Neet cycloate           R                                       R    
Roundup PowerMax 3 glyphosate R R R R R R R R R R R R R R R R R R R R R R R R R R R R
Sandea halosulfuron-methyl R   R         R R R R   R     R       R   R   R       R
Scythe pelargonic acid R R R R R R R R R R R R R R R R R R R R R R R R R R R R
Select Max clethodim R R R R R R R     R R R   R R R R R R R R R R R R R R R
Sharpen saflufenacil     R         R R                   R                  
Simazine 90 WDG simazine               R R                                      
Sinbar WDG terbacil R                                                      
Solicam DF norflurazon R                                                      
Sonalan HFP ethalfluralin     R                                   R              
Stinger clopyralid       R R     R R                               R R    
Surpass EC acetochlor               R R                                      
TreflanHFP trifluralin R   R   R R R     R R         R R   R R R   R   R     R
Valor EZ flumioxazin                                                     R  
Zidua pyroxasulfone               R R                                      

*Federally restricted herbicide

**Indicates an indemnified label for use in this crop due to potential for crop injury. Users must agree to a waiver of liability through the Syngenta website to access the label for this use.

Select Weeds Controlled by Herbicide Active Ingredients According to Labels (Table 31)

Select Weeds Controlled by Herbicide Active Ingredients According to Labels (Table 31) Evonne Gong
Table 31: Select Weeds Controlled by Herbicide Trade Names According to Labels
TRADE NAME ACTIVE INGREDIENT Annual Bluegrass Barnyard Grass Crabgrass Fall Panicum Foxtail Goosegrass Johnsongrass (rhizome) Johnsongrass (seedling) Quackgrass Yellow Nutsedge Bindweed Carpetweed Chickweed Cocklebur Galinsoga Jimsonweed Lambsquarters Morning Glory Mustard Nightshade Pigweed Purslane Ragweed Smartweed Velvetleaf Wild Buckwheat
2,4-D Amine 4 2, 4-D                     H C C C C C C C C   H C C C H  
Aatrex 4L* atrazine C PC PC   PC                 C   C C C C C C C C C PC C
Accent Q nicosulfuron   C         C C C             C   C     C     C    
Aim EC carfentrazone-ethyl                     H H       H C C   C C     C C  
Aquesta 4F sulfentrazone     C     C       C   C C   C C C C C C C C   C    
Assure II quizalofop   C C C C C C C C                                  
Basagran 5L bentazon                   H H     C H C C H C H   H H C C  
Broclean bromoxynil                                 C PC PC C PC   PC C PC C
Cadet fluthiacet-methyl                               C C C   C C     C   PC
Callisto mesotrione     C             PC   C C C C C C PC C C C   PC C C PC
Caparol 4L prometryn   C C C C C               C     C C C C C C C C    
Casoron 4G dichlobenil C   C   C       C C   C C       C   C   C C C C    
Chateau EZ flumioxazin C C C C C C   C     PC C C     C C C C C C C C C C C
Clarity dicamba                     C C C C   C C C C C C C C C C C
Clean Slate clopyralid                               C       C     C PC   C
Command 3ME clomazone   H H C C C   H             H H H         H   H C  
Curbit ethalfluralin     C C C C   C       C         C       C C        
Dacthal Flowable DCPA EPA issued an emergency order on August 6, 2024 prohibiting all use, distribution, and sale of this product.
Devrionol 2-XT napropamide C C C C C C   C       C         C       C C C      
Dual Magnum** s-metolachlor   C C C C C   PC   C         C         PC C PC        
Eptam EPTC C C C C C C   C C C   C C       C C   C C C        
Evik DF ametryn   C C C P C               C     C C C   C   C C C  
Fusilade DX fluazifop-p-butyl   C C C C C H C H                                  
Goal 2XL oxyfluorfen                               C C C C C C C   C C  
Gramoxone SL 3.0* paraquat C C C C C C   PC PC   PC C C C C C C PC C C C C PC C C C
Impact topramezone   H H H C C   H     PC C C C C C C PC C C C PC C C C  
Kerb 50-W* pronamide C C C C C C           C C       C C C C   C   C    
Laudis tembotrione   C C   C C           C C C C C C PC C C C   C C C PC
Lorox DF linuron   C C C C C           C C PC C   C PC C PC C C PC   PC  
Matrix SG rimsulfuron   C C C C C           C C C     C C C   C C C C C C
Metribuzin metribuzin C C C C C     PC PC PC     C PC     PC PC C PC C C PC PC PC  
Outlook dimethenamid   C PC C PC C   C       C   PC C C C   C   C C C C C  
Poast sethoxydim C C C C C C   C   C   C         C     C C C C      
Prefar 4-E bensulide   C C C C C C C C                                  
Princep 4L simazine C C C C C C           C C       C C C C C C C C    
Prowl H2O pendimethalin   C C C C C                                        
Raptor imazamox   C C C C C   C         H       C   C C C C   C H  
Reflex fomesafen   PC PC   C       PC PC     C C   C C PC C C C PC   PC C PC
Reglone diquat   PC PC PC PC PC   PC     PC C   C   C C C C C C C C C C  
Ro-Neet cycloate C C C   C         C             C     C   C     C  
Roundup PowerMax 3 glyphosate C C C   C         C             C     C C C        
Sandea halosulfuron-methyl C C C C C C C C C C C C C C C C C C C C C C C C C C
Scythe pelargonic acid                   C     C C C C C PC C   C C C C C  
Select Max clethodim C C C C C C H C C                                  
Sharpen saflufenacil                     PC C PC C C C C C C C C C C C C C
Simazine 90 WDG simazine C C C C C C           C C       C     C C C C C    
Sinbar WDG terbacil C C C C C       H H     C       C   C C   C   C    
Solicam DF norflurazon C C C C C C PC C PC PC   C C PC     PC PC C PC PC C PC PC C  
Sonalan HFP ethalfluralin C C C C C     C       C C       C     H C C       C
Stinger clopyralid                           C C C       C     C PC   C
Surpass EC acetochlor   C C C C C   PC       C     C   C     C C C   C    
TreflanHFP trifluralin C C C C C     C     C C C       C       C C        
Valor EZ flumioxazin C C C C C C   C     C C   C   C C C C   C C C C C  
Zidua pyroxasulfone C C C C C C   C   PC   C PC     PC PC PC   C C C PC   PC PC

C = Control

H = Control at high rate

PC = Partial control/suppression

* Federally restricted herbicide

 

Vertebrate Pest Management

Vertebrate Pest Management Evonne Gong

USDA Wildlife Services staff are available to assist with a variety of wildlife damage issues. Their telephone number for New Hampshire & Vermont growers is (603) 223-6832. For growers in Connecticut, Massachusetts and Rhode Island: (413) 253-2403. For Maine: (207) 629-5181. The website is http://www.aphis.usda.gov/wildlife_damage. Trapping is often highly regulated; laws are restrictive and may be complex. Environmental Police Officers enforce trapping laws. Know the current laws and regulations before trapping any wildlife. Reductions in animal numbers by lethal methods fail to provide a long-term solution from wildlife damage in the absence of habitat modifications and exclusion methods. Most nuisance wildlife will repopulate areas soon after control efforts have ceased. Habitat modification and exclusion methods often require more expense and initial effort, but these methods will result in more durable damage prevention.

Deer

White-tailed deer are common in New England, and sweet potato leaves and vines are among their most preferred foods. In some areas, they heavily attack pumpkins, both the plants and fruit. We also see damage to butternut squash, lettuce, and occasionally tomato and other vegetable plants. They are very active at night, but during the summer they are almost as active during the day.

Fencing: Permanent mesh fencing can keep them out if it is 8-10 feet high. Such fencing restricts vehicle movement, so carefully consider turning distances, entrance locations, and gate width before making an investment in permanent fencing. Temporary electric fencing is relatively inexpensive and simple to set up. It can work very well if you bait it immediately after erecting it. Even a single electric strand at 36-40" can work if the deer have other feeding options. White electric tape is especially visible and works well in this application. The most common method to bait an electric fence for deer is to apply peanut butter to strips of aluminum foil and fold them (sticky side in) over the fence at about a 40" height, at intervals of about 30-50 feet. By licking the tasty treat they can smell, deer quickly learn that the fence can hurt them, and they keep away. Usually, the baits do not need replenishing if they are used for less than one growing season.

Repellents for deer are designed to work by odor or taste. Most commercial products are not labeled for direct application to vegetable crops.

Shooting is one option that growers may consider, but the rules vary greatly from state to state. Sometimes officials will readily give out permits to shoot offending deer. Shooting is not as effective as fencing and brings on issues of safety, neighbors, and farmer image. Deer are protected species in all New England states, so check with state Fish and Game authorities or USDA Wildlife Services staff before shooting.

Birds

Most birds in New England that are pests of vegetables are species with either partial or complete legal protection. State, federal, and international laws/treaties are involved in their protection. This limits some of our management options. Crows and ravens often pull out seedling corn plants, to reach and consume the seed. They, along with blackbirds and starlings, frequently attack milk stage corn, especially in varieties where the ears are not well covered by the husks. Turkeys feed on kale, collards, lettuce, and mesclun mix. They also peck both green and ripe tomato fruit. Canada geese like to eat grasses and winter rye, and sometimes corn. Occasionally birds cause losses by defecating on the crops. This is most common when open containers of product are placed in an open shed or barn, where English sparrows can perch in the rafters above. In that situation, growers can install netting to exclude birds from the rafter area or repellant spikes to discourage perching. Canada geese defecating while grazing on grassy weeds can be an issue on low crops that are eaten fresh, like lettuce and spinach.

There are a variety of devices designed to manage bird problems.

Netting is one possibility but is most appropriate for high-value perennial crops, not most vegetables. Some of the insect and hail netting designed to protect mesclun mix and other low crops can be supported by wire hoops and stops turkey feeding. 

Taste Repellents. Some taste repellents are available (e.g. methyl anthranilate) for use on some crops, but they are applicable to few vegetable crops and have variable results in our area. An exception is 9,10-anthraquinone, sold as Avipel. It is registered as a seed treatment on corn to keep birds from walking down the rows and pulling out the seedlings. Currently, it is registered in Maine, Vermont, New Hampshire and Massachusetts.

In states where anthraquinone is not registered, growers have used two methods to reduce seedling pulling by crows and ravens. One method is to set up tomato stakes in a zig-zag pattern on a recently planted sweet corn field. Attach fishing line to the stakes. This seems to deter crows from landing. When the seedlings are large enough that the birds can’t pull them out, you can reel up the fishing line, retrieve the stakes and put them in your next planting. Another alternative is to plant sweet corn into a low standing stubble. It can make the young plants harder for the crows to spot.

Scare devices can be relatively effective, especially on flocking species. All birds become habituated to scary noises, especially if they are used alone and constantly. Therefore, incorporating variability (in sound, location, etc.) is important to being successful with scare devices. The University of New Hampshire resource Bird Damage Prevention For Northern New England Fruit Growers covers most scare devices. Two relatively new ones not covered in that publication are Air Crow and laser lights. Air crow is a colored nylon tube/scarecrow attached to a blower. When in use, it moves constantly and can be quickly turned off when not in use. Set it in a location that makes it visible. For tall crops, that might be on a bin or stand. As with other scare devices, it is most effective when combined with other methods. Laser bird deterrents mounted on a firm mast are available. Coverage area depends on product, site, light, and weather conditions. Some New England vegetable growers have been very happy with the results scaring various birds, despite the high cost.

Auditory bird scare devices can be fairly effective, especially if the noises they create are varied. Automated propane cannons can be effective for a relatively short time, but are very annoying to neighbors, customers, and farm workers. In New England, automatic cannons have been the source of several serious disputes with neighbors. Screamers and bangers are auditory devices that are fired from a pyrotechnic shot launcher (looks like a plastic handgun). They can cost $2.50 or more per shot but can occasionally be helpful to move out a flock of birds. Regulations cover the purchase and use of these devices. Be sure to check local regulations about their use before you begin.

Silhouettes of coyotes or other predators don’t work very well to scare birds (or other vertebrate pests of vegetables). Effigies are slightly more effective, especially those that employ movement. They are still more effective if you regularly move them to different spots. If you combine them with auditory scare devices, the effectiveness usually increases.

Some growers employ scare-eye balloons to protect sweet corn from pecking. Growers report that the light colored balloons work better than the dark ones. There are some larger ones with “holographic” eyes that seem to follow you as you walk by. Growers have had relatively good results with them. With all of the balloons, it is important to suspend them from high poles 2-5 feet above the crop.

Shooting is rarely effective at controlling bird problems. The main effect is scaring away the survivors. There are local, state, and international laws that affect if, where, and how shooting may be employed.

Rodents

Rodents are distinguishable by their teeth. They have sharp, opposing incisors plus strong molars to grind up material. Between the incisors and molars, there is a broad gap with no teeth.

Woodchucks

Woodchucks especially like to eat beans, peas, carrot greens, alfalfa, clover, and grasses. They also eat cabbage, broccoli, tomato, dandelion, and other plants. There are few succulent plants that they won’t eat. They don't seem to prefer corn. They are most active early in the morning and late in the afternoon. They dig extensive burrows that are used as escape cover, shelter, or overwintering sites by many other animals. Cottontail rabbits, skunks, raccoons, foxes, coyotes, snakes, weasels, and chipmunks are among the animals that use woodchuck burrows. Woodchucks are also prey for foxes, coyotes, bobcats, fishers, eagles, and large hawks. Consider these points before jumping to lethal control measures for woodchucks. Both lethal and non-lethal control options are available.

Non-lethal Measures. Frightening devices don’t seem to be effective at deterring woodchuck feeding. Although some taste repellents are available, they are not very practical for vegetable crops that people will be eating. Fencing can be very effective but restricts vehicle movement. Also, if you depend on fencing, be sure the woodchuck burrow is not inside the fence. Since woodchucks can climb and burrow, the most effective alternative is electric fencing. An effective combination is one wire 4" off the ground and a second at 8 or 9" high. Dealers offer a wide variety of plug-in, battery, and solar powered UL-approved chargers. Keep the fence clear of any obstructions or vegetation that might short out the electric pulses.

If you use non-electric fencing, buy a mesh size smaller than 2"x2" inches, especially close to the ground, as young woodchucks can sometimes squeeze through that mesh size. Common chicken wire rusts away quickly—the woodchucks may push through it by the second growing season. Non-electric fencing should have some means of preventing the woodchucks from burrowing underneath. Fences can be buried to a depth of 10-12". Or, the lower 1 ft of fence can be bent 90° outward, to form an "L", then laid on the ground and secured by anchoring the "L" into the ground. Another option is laying an 18" wide strip of galvanized fencing on the ground below the fence, keeping the vertical fence flush with it. Non-electric fences need to be at least 3 feet high. Bending the top 12-15" outward at about a 45-degree angle will help deter them from climbing a non-electrified fence. Don't neglect the gate. That is often the spot where defenses are the weakest. If animals try to burrow underneath, install a board dug into the ground and flush with the bottom of the gate, or lay down a length of fencing as described above.

Live trapping is a possibility in some situations, but it carries risks. Small details in setup make big differences in the success rate. If a carrier of rabies were trapped, handling it could be a risk to any non-vaccinated person who was exposed. Trapping and translocating a woodchuck from its home is subjecting the “humanely trapped” animal to a prolonged, very stressful ordeal that often ends in its death. Suitable habitat is farmland with open fields and an abundance of short grasses. Farmers or gardeners are not likely to agree to releasing animals on their property, and woodchucks are not woodland creatures. In some New England states, laws prohibit the practice of transporting and releasing trapped animals.

The most effective technique is to place the trap directly at the burrow entrance and use a barrier of boards or other material to direct the animal into the trap as it leaves its burrow. No bait is needed in this situation. Trap placement elsewhere is much less effective, but sometimes the woodchuck can be enticed inside with fresh apple slices or fresh carrots or lettuce. Change baits daily.

Lethal Controls. Use lethal controls cautiously, after careful thought. They can end up killing non-target animals. Gas cartridges are cardboard cylinders filled with slow-burning, asphyxiating chemicals. Locate an active burrow, and treat when you are sure the woodchuck is inside. Find and close all but one entrance, and prepare a sod plug for the opening. Attach the cartridge to a 3 foot-long branch, light the fuse, and place it well inside. Immediately seal the entrance. Most failures with cartridges are from the fuses going out (often because loose dirt covered them, or they were thrown). Sometimes they fail because the woodchuck was somewhere else when the burrow was fumigated. Upon its return, it just re-opens the burrow. Never use a gas cartridge near flammables or under a wooden structure.

Conibear traps are body-gripping steel traps that almost instantly kill an animal that tries to move through. If a pet or other non-target animal walks through one, there is no second chance. Use these traps only where you are certain the intended target is the only animal that can enter. They are usually placed just inside the burrow, to trap the occupant as it enters or leaves. Conibear sizes 160 and 220 are appropriate sizes for woodchucks. These traps are dangerous and most states require users of them to obtain a permit or license. Contact your state animal authority before attempting to use a conibear trap.

Shooting is an option that has a low risk of harming non-target animals if done carefully. In many New England states, woodchucks can be shot by anyone with a hunting license, or by farmers on their own property, protecting their crops. In most New England states, there is no closed season on woodchucks. A .22 caliber rifle with hollow point cartridge is the most commonly employed weapon for woodchuck control. When shooting, take extreme care that the area is safe for a shot. A .22 caliber long rifle bullet can travel nearly a mile if it does not strike something first. They easily ricochet off hard surfaces.

Voles

Voles can attack a wide range of plants. In New England, they have been reported attacking tomato, asparagus, potato, sweet potato, carrot, and other vegetables. Grasses are especially favored foods for several species of voles. There are 4 vole species (meadow, southern redback, rock, pine) that can cause problems in New England, but most suspicion falls on meadow voles and pine voles. Pine voles primarily live and feed in tunnels underground and readily attack root crops: carrot, beet, potato, and sweet potato. They have very short tails, never longer than their hind feet. Meadow voles largely live above-ground and have tails that are longer than their hind feet. Voles have less prominent eyes than mice, and their ears are buried in the fur. Mice have prominent ears.

We have few options to manage pine voles on vegetable farms. Problems are most common in soils that are adjacent to woodlands or orchards. Soils that are poor for pine voles are those that are commonly waterlogged, have very high clay content, or are almost entirely sand. Tunneling is difficult in those conditions. Meadow voles mostly live above ground and often chew off plants just above the soil line, especially if there is a lot of vegetation to hide them. Weedy fields and field edges are common sites of attack. Sometimes voles attack when very young plants are still in liner or plug trays on the ground in a high tunnel. Meadow voles have an extremely high reproduction rate, so their populations can rebound rapidly after controls are implemented.

Voles prefer areas with good cover, so maintaining good weed control is important to reduce the risk of vole problems. Piles of debris placed right next to high-risk crops (like a high tunnel full of transplants) are invitations for vole problems. Mulches, including organic mulches, woven blankets, or plastic mulches, can encourage vole problems.

Rodenticides: There are rodenticides registered for use against voles in orchards, fruit groves, nurseries, and highbush blueberries. Currently, there are no rodenticides registered for use in vegetable fields. There are several rodent baits registered for use in and around buildings (commensal use), but are largely intended for use against mice and rats and the baits are formulated to appeal to those species, not voles. Contact your local Extension agent or USDA Wildlife Services to discuss the use of a rodent bait targeting voles around high tunnels or farm buildings.

Be very cautious about using the second-generation anticoagulants—brodifacoum, difethialone, and bromadiolone. These materials (especially brodifacoum) have been found in an amazingly high percentage of dead, sick, or injured predatory birds and predatory mammals in the northeast states. EPA responded to this problem by drastically reducing the availability of brodifacoum products for use by non-licensed applicators, but it is still available for licensed applicators to apply, in and around buildings. If pets or wildlife can reach the bait, they can be poisoned.

In most cases, rodenticide labels state that rodent baits must be used in bait stations. In part, this is to reduce the risk of direct poisoning to domestic animals. However, secondary poisoning can occur when a target pest becomes weakened or dies as a result of eating the bait, then a second, non-target animal eats the target pest and is poisoned.

Rodenticide labels are usually available to examine at the manufacturer’s website. Common manufacturers that include some field-applied products registered in New England include:

Make sure any rodenticide you plan to apply is registered in your state. See Pesticide Registration under Pesticide Safety for more information.

Trapping is a possibility for meadow, redback, and rock voles, but it isn’t very practical. Tiny details have a major effect on trapping success. In a situation where high-value plants are concentrated and damage is significant (e.g., high tunnels full of plugs or transplants) careful trapping might help. Vole tubes can be effective traps. Using scrap lumber, create a 16-18" long narrow tube, whose rectangular interior dimensions fit a standard mousetrap, leaving enough room for the spring bar to clear the ceiling. For most traps, that inside measurement would be 2’’ wide and 2.5” high. At the center of one side, leave an opening large enough to easily insert a mouse trap. Consider placing two traps in a tube, each one with the trigger facing its respective end. Then gently set the tube in the desired location and place a piece of cardboard to cover the side opening. No bait is needed. Voles like traveling in protected runs and this catches them as they try to use an inviting runway. It keeps the trap safe from your cat or dog, and your workers’ toes. Tubes can be placed along established paths between the trays of plug plants.

Vole Problems in High Tunnels/Greenhouses. Growing vegetables inside structures presents a different set of regulations, compared to outdoors. The use of rodenticides is one area that is not very clearly defined in this situation. Many rodenticides are labeled for “commensal” (in and around buildings) rodent control, not for use on or around a crop. When you grow a crop inside the structure, that brings up new legality issues. Also, commensal rodenticides are typically formulated to entice rats and mice, not voles. Cats find warm greenhouses and high tunnels especially inviting, and this behavior increases the risk of poisoning them if you use rodenticides in or around those structures. As described above, secondary poisoning is a significant concern with some rodenticides. Avoid using rodenticides inside high tunnels or other structures where food crops are grown for harvest unless the product is specifically labeled for this use and for the pest(s) you are trying to control.

For a greenhouse in which you plan to grow vegetables, it is possible to reduce the chances of having vole problems by using ¼ inch mesh hardware cloth to seal all openings at or near ground level. Bury the edges well. High tunnels are much harder to protect from vole entry. In both high tunnels and greenhouses, control weeds well inside. Keep the vegetation around the structures well-mowed or controlled with herbicides. 

Other Rodents

Gray squirrels commonly raid ears of corn, especially in fields that are close to woods. Damage is sporadic, so controls are usually not warranted. Gray squirrels are protected species in all New England states.

Mice tend to be seed eaters, though some will feed on fruits when given an opportunity. The white-footed mouse is a common New England species that frequently moves into buildings, especially in fall and winter. Usually, we do not see evidence of them attacking vegetable plants. Mice have prominent ears and eyes, while voles tend to have smaller ears and less prominent eyes.

Muskrats are rodents that are strongly associated with ponds, marshes, and slow rivers. They eat aquatic plants, but occasionally attack corn, beans, wheat, or oats that are growing adjacent to wetlands. Damage is uncommon, so controls are not usually warranted.

Rats (Norway, roof) occasionally attack harvested vegetables stored in containers indoors, but rarely are reported attacking plants in the field. Rat control can be very demanding. It requires eliminating food sources, plugging holes in walls, and careful use of traps and/or rodenticides. Rats are notoriously reluctant to try new foods (like rodent baits), and resistance to rodenticides is a problem. Contact your local Extension specialist for additional resources on rat control in indoor farm settings.

Lagomorphs (Rabbits & Hares)

Rabbits and hares are close relatives of rodents. Cottontail rabbits are the most common species attacking vegetables. We have two species here: New England cottontail and the larger Eastern cottontail. They eat a wide variety of vegetable plants (carrot, pea, bean, beets, lettuce, spinach, and others). They do not tend to feed on corn, squash, tomato, cucumber, or potato. They eat many cut flowers (e.g., tulips). European and snowshoe hares can be found in western Connecticut and northern New England, respectively, but these are not usually associated with damage to vegetables. 

The most common form of lagomorph control is fencing. Two-foot high fencing with 1" mesh is sufficient if it is buried slightly into the ground. Chicken wire can work, but very young rabbits can sometimes squeeze through. Electric fencing designed for woodchucks or raccoons is often also effective against lagomorphs and less expensive than erecting mesh fencing.

Thiram is a fungicidal seed treatment that also acts as a taste repellent against lagomorphs, but it is not labeled for use on vegetables other than as a seed treatment. Shooting may be an option in some situations, but the aforementioned species are protected, so be sure to check first on state regulations and follow gun safety practices. For rabbit control, .22 rimfire rifles are commonly used.

Carnivores 

Raccoons

Raccoons are a common presence and are especially active at night. Before the raccoon strain of rabies moved through New England in the mid-1990s, raccoon damage to sweet corn was a very serious problem, and many growers used electric fences to protect sweet corn in the milk stage. Today sweet corn damage from raccoons is less common. Raccoons also attack cantaloupe and watermelon fruits.

Fencing. The most common and effective control for raccoons is electric fences, with one wire at 6" height and a second at 12". Sometimes a single wire at 6" works well. Be certain that vegetation is cleared from the fence, or it will reduce the shock an animal receives when it contacts the wire. Fencing will limit vehicular traffic, but temporary clip-on gates are easy to install.

Trapping. Some farmers employ trapping, but it can be difficult and time-consuming to do properly and may be subject to local and/or state laws. The raccoon is a protected species, and the rules vary state to state. Live trapping requires a sturdy trap and an effective bait, e.g., sardines. Transporting trapped animals is illegal in some New England states. Leg-hold or lethal body-gripping traps can be effective but are dangerous for non-target animals, including humans and typically require permits or licenses. Contact your state animal control authority before attempting to use one of these traps. If you do use traps and need to move a dead raccoon, use rubber gloves. Raccoons can harbor the nematode Baylisascaris procyonis (“raccoon roundworm”) that can parasitize people. Raccoons can also be infected with rabies virus, which is lethal to people.

Other Carnivores

Opossums occasionally feed on sweet corn, and some fruits. They are omnivores that feed on carrion, as well as fruits and grains. They are more active at night than during the day. Electric fencing is the most appropriate control method.

Red foxes are common in New England and sometimes feed on ears of corn or cantaloupe fruits. We rarely get reports of significant damage. Foxes are valuable predators of voles and other pests, so we generally consider their presence beneficial. They are protected in all New England states.

Black bears are more common in northern New England than southern New England. Bears readily attack sweet corn and field corn in the milk stage. Damage often occurs in large spots in the middle of the field, where the bears pull down all of the stalks and are hidden from view. Since black bears are protected by laws, contact your state Fish & Game officials or USDA Wildlife Services staff for assistance if you have a bear problem.

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