Disease Management

 

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 creating 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.
  • 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.
  • Do not let pathogens get a head start by practicing good sanitation. 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.
  • Purchase plants from a reputable source and protect plants from pathogens by following a suitable 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 diseased.
  • 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.

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 crop.

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 and state specialist can assist you in determining the cause (see 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 23, 24, and 25.

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 Group). To select fungicides with different modes of action, see resistance group (FRAC) in Table 25 and in the following section Fungicides and Bactericides Alphabetical Listing 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 using a Group 1 herbicide and a Group 1 insecticide or fungicide.

Toxicity of Fungicides

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.

Table 25: Information about Fungicides and Bactericides

Active Ingredient

Signal Wordz

Trade Name

Resistance Group (FRACy code)

Dermal LD50 mg/kg Oral LD50 mg/kg
ametoctradin & dimethomorph C Zampro 45 & 40 >5,000 >500 <2,000
azoxystrobin

C

Quadris, Dynasty 11 >2,000 - 4,000 >2,000 - 5,000

azoxystrobin & chlorothalonil

W

Quadris Opti

11 & M5

>5,000

1,750

azoxystrobin & difenoconazole C Quadris Top 11 & 3 >2,000 >2,000
azoxystrobin & flutriafol C Topguard EQ 11 & 3 >5,000 >5,000
azoxystrobin & mefenoxam C Ridomil Gold SL 11 & 4 >4,000 >5,000

azoxystrobin & propiconazole

W

Quilt, Quilt Xcel, Trivapro B

11 & 3

>5,000

1,750 / 1030

azoxystrobin & tebuconazole W Custodia 11 & 3 >2,000 >300
benzovindiflupyr D Trivapro A 7 >5,000 550
benzovindiflupyr & difenoconazole W Aprovia Top 3 & 7 >5,000 1,750
benzovindiflupyr & azoxystrobin & propiconazole W Trivapro 7 & 11 & 3 >2,000 550

boscalid

W

Endura

7

>2,000

>2,000
chlorine

 D

Agclor 310 NC >20,000 8,910
chlorothalonil

C ,W

Bravo Weather Stik, Bravo Ultrex, Bravo Zn, Echo 720, Echo 90 DF, Equus 720 SST, Initiate 720, Initiate Zn, Orondis Opti B M5 >2,000 -10,000 >3,750 -10,000
chlorothalonil & cymoxanil C Ariston M5 & 27 >5,050 >5,000
chlorothalonil & oxathiapiprolin D Orondis Opti M5 & 49 >2,000 >5,000
Coniothyrium minitans C ContansOG BM2 >2,500 >2,500
copper hydroxide C, D Champ WGOG, Champ Dry Prill, Champ Formula 2 Flowable, KalmorOG, Kocide 2000, Kocide 2000-OOG, Kocide 3000, Kocide 3000-OOG, ChampION++OG, Nu-Cop (50DFOG, 50WPOG, HBOG), Kentan DF M1 1,300->5,000 489-1,847
copper hydroxide & copper oxychloride  W Badge X2 OG M1 >2,000 >300
cuprous oxide C Nordox 75 WGOG M1 >2,000 3,165
copper octanoate C Camelot O, Cueva M1 >2,000 >2,000
copper oxychloride and copper hydroxide C, W Badge SC, Badge X2 M1 >300 >2,000
copper sulfate (basic copper) C, W, D Basic Copper 53OG, Cuprofix Ultra, Cuproxat FLOG, Cuproxat, Phyton 35, MasterCopOG M1 >2,000-8000 1,000-2,521

cyazofamid

C

Ranman, Ranman 400 SC

21

>2,000

>5,000

cyflufenamid C Torino U6 >2,000 <,2,000
cymoxanil

W

Curzate 60 DF 27 >2,000 >433

cyprodinil & fludioxonil 

C

Switch 62.5

9 & 12

>2,000

>5,000

difenoconazole & cyprodinil

C

Inspire Super

3 & 9

>5,000

5,000

dimethomorph

C

Forum 15 >2,000 >5,000

famoxadone & cymoxanil 

C

Tanos

11 & 27

>2,000

>5,000

fenamidone

C

Reason 500 SC

11

>5,000

>5,000

fenhexamid

C

Decree 50 WDG

17

>2,000

>2,000

fluazinam

W

Omega 500F, Omega TopMP

29

>2,000

>5,000

fludioxonil

C

Maxim4FS, Maxim PSP, Cannonball WG, Emblem 12 >2,020 1,971
fludioxonil & mancozeb C Maxim MZ 12 & M3 >5,000 >5,000

fluopicolide

C

Presidio

43

>4,000

>2,000

fluopyram C Velum Prime 7 >2,000 >2,000
fluopyram & pyrimethanil C Luna Tranquility 7 & 9 >2,000 >2,000
fluopyram & tebuconazole C Luna Experience 7 & 3 >2,000 >2,000
fluopyram & trifloxystrobin C Luna Sensation 7 & 11 >2,000 >2,000
flutolanil C Moncut 70 DF 7 >5,000 >5,000
flutolanil & mancozeb C Moncoat MZ 7 & M3 >5,000 >5,000
flutriafol C Topguard Fungicide, Rhyme 3 >2,000->5,000 >2,000
fluxapyroxad & pyraclostrobin C Priaxor, Merivon 7 & 11 >5,000 >300-<2,000
fosetyl aluminum

C

Aliette WDG 33 2,000 >5,050
hydrogen peroxide & peroxyacetic acid D Oxidate 2.0OG, ZeroTol 2.0OG NC 1,040 3,622
iprodione

C

Iprodione 4L AG, Rovral 4F, Nevado 4F 2 1,170 - 2,000 2,000 - 2,860
mancozeb

C

Penncozeb (75DF, 80WP), Manzate (Max, Pro-Stick), Dithane (M-45, F-45 Rainshield), Potato Seed Treater (6%, PS), Roper (DF, DF Rainshield) M3 >2,000 >5,000

mancozeb & copper 

D

ManKocide

M3 & M1

>5,000

2,535

mandipropamid 

C

Revus, Micora, Orondis Ultra B

40

>5,000

>5,000

mandipropamid & difenoconazole

C

Revus Top

3 & 40

>5,000

2,958

mefenoxam C Ridomil Gold (GR, SL), Apron XL, Ultra Flourish 4 2,020 1,172
mefenoxam & chlorothalonil

W

Ridomil Gold Bravo SC 4 & M5 >2,020 1,172
mefenoxam & copper 

D

Ridomil Gold Copper 4 & M1 2,020 560
mefenoxam & mancozeb 

C

Ridomil Gold MZ WG 4 & M3 >2,000 >5,000
metconazole C Quash 3 >5,000 1,750
metrafenone C Vivando U8 >5,000 >5,000
metiram C Polyram 80 DF M3 >2,000 >5,000
myclobutanil

W

Rally 3 >5,000 1,870
oxathiapiprolin C Orondis (Ultra A, Gold 200, Opti A) 49 >5,000 >5,000
oxathiapiprolin & mandipropamid C Orondis Ultra 49 & 40 >5,000 >5,000
PCNB C Blocker (4F, 10G), Terraclor 400 14 >2,020 >5,050
penthiopyrad C Fontelis 7 >5,000 >5,000
phosphorus acid (salts of)

C

Agri-Fos, Alude, Fosphite, KPhite, Phostrol, ProPhyt, Rampart, Reveille 33 >2,000 >5,000
polyoxin D C Oso 5% SC AKA VeggieTurbo 5 SCOG, Ph-D, Affirm WDG 19 >2,000 4,916
potassium bicarbonate C KaligreenOG, MilStopOG NC >5,000 2,700
potasium dihydrogen phosphate C Nutrol NC    
propamocarb

C

Previcur Flex 28 >3,920 2,000-8,550
propiconazole

W

Tilt, PropiMax EC, Bumper (41.8EC & ES) 3 >5,000 1,310

propiconazole & trifloxystrobin

W

Stratego

3 & 11

>5,050

4,757

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

pyraclostrobin

C, W

Headline, Headline SC, Cabrio EG

11

200 - >2,000

2,000 - 4,000

pyraclostrobin & boscalid 

C

Pristine, Pageant Intrinsic

11 & 7

>2,000

1,490

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

pyraclostrobin & metconazole

W

Headline AMP

11 & 3

>5,000

500

pyraclostrobin & metiram

C

Cabrio Plus

11 & M3

>2,000

> 500-<2,000

pyrimethanil

C

Scala SC

9

>5,000

4,505

quinoxyfen

C

Quintec

13

>2,000

>2,000

streptomycin

C

Agri-Mycin 17 25 >2,000 >5,000

sulfur

C

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

M2

>2,000

>2,000

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

thiabendazole

C

Mertect 340-F

1

>5,050

>5,000

thiophanate-methyl

C

Topsin M WSB, Topsin 4.5 FL,  Nufarm T-Methyl (70WSB, 4.5F), Incognito (4.5 F, 85 WDG) 1 >2,000 >5,000
triphenyltin hydroxide D Super Tin (80 WP, 4L) 30      500      160
trifloxystrobin

C

Flint Extra, Gem 500 SC 11 >2,000 >5,050

triflumizole

C

Procure 480 SC, Trionic 4SC

3

>5,000

>1,400

thiram

C

42-S Thiram

M3

>4,400

2,950

zoxamide & chlorothalonil C Zing! 22 & M5 >5,000 1,750-5,000
zoxamide & mancozeb

C

Gavel 75 DF 22 & M3 >5,000 >5,000

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

y 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.

Fungicides and Bactericides Alphabetical Listing by Trade Name

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 M3 

Actigard 50 WG (acibenzolar-S-methyl): Plant defense activator used for bacterial diseases and Downy Mildews. REI 12h, Group 21

Actino-IronOG (Streptomyces lydicus WYEC): Biological soil and seed treatment for Fusarium, Rhizoctonia, Pythium, and Phytophthora with added iron. REI 4h, Group NC

Actinovate AG (Streptomyces lydicus): Biological for greenhouse use only in vegetable crops. REI 1h, 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 fungicide active against Pythium, Phytophthora, and downy mildew. REI 4h, Group 33

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 33

Alude (phosphorous acid): A fungicide active against Pythium, Phytophthora, and downy mildews labeled for greenhouse transplant production. REI 4h, Group 33

Apron XL (mefenoxam): A seed treatment 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, 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 SC  (copper oxychloride + copper hydroxide): A bactericide and fungicide. REI 24h, Group M1

Basic Copper 53OG (basic copper sulfate): A broad-spectrum fungicide. REI 48h, Group M1

Bio-Save 10 LPOG (Pseudomonas syringae ESC-10): Post harvest decay of potato. Group NC

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

Blocker 4F (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 NC

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

Bravo (Weather Stik, Ultrex, ZN) (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M5

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 certin diseases of potato. REI 24h, Groups 11 & M3

Camelot OOG (copper soap): Copper product labeled for greenhouse use on vegetable transplants. REI 4h, Group M1

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

Catamaran (potassium phosphite + chlorothalonil): broad-spectrum fungicide and plant activator. REI 12h, Groups 33 & M5

CeaseOG (Bacillus subtilis QST 713): Biological protectant fungicide. REI 4h, Group 44

Champ WGOG (copper hydroxide): Copper fungicide. REI 48h, Group M1

Champ Dry Prill (copper hydroxide):  Copper fungicide. REI 24/48h, Group M1

Champ Formula 2 Flowable (copper hydroxide): Copper fungicide. REI 48h, Group M1

ChampION++ (copper hydroxide): Copper fungicide. REI 48h, Group M1

CompanionOG (Liquid, WP) (Bacillus subtilis strain GB03): Biological fungicide. REI 4h, Group 44

Contans WG OG (Coniothyrium minitans): For Sclerotinia sclerotiorum and Sclerotinia minor diseases. (Bayer fomula not labeled for tomato). Group NC

Cuprofix Ultra 40 Disperss (basic copper sulfate): A broad-spectrum fungicide. REI 48h, Group M1

Cuproxat, Cuproxat FLOG (basic copper sulfate): A broad-spectrum fungicide. REI 48h, Group M1

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

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

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

Dithane (M-45, F-45 Rainshield) (mancozeb): A broad-spectrum, protectant fungicide. REI 24h, Group M3

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

Double NickelOG 55 and LC (Bacillus amyloliquefaciens): Microbial fungicide. REI 4h, Group 44

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

Echo (90DF, 720) (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M5

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 12h, Group NC

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 M5

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 7

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 (phosphorus acid): A phosphorous acid fungicide active against Pythium, Phytophthora, and downy mildew. REI 4h, Group 33

Gavel (75 DS, DF) (zoxamide + mancozeb): A broad-spectrum protectant fungicide for disease control in potatoes, cucurbits, and tomatoes. REI 48h, Groups 22 & M5

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

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 48h, 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

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 M5

Inspire Super (difenoconazole + cyprodinil):  For powdery mildew. REI 12h, Groups 7 & 9

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

JMS Stylet-OilOG, JMS Stylet-Oil (paraffinic oil): 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): broad-spectrum bactericide and fungicide. REI 48h, Group M1

Kentan DF (copper hydroxide): broad-spectrum bactericide and fungicide. REI 48h, Group M1

K-Phite 7LP (phosphorus acid): Pythium, Phytophthora, and downy mildew; also labeled for greenhouse transplant production.  REI 4h, Group 33

Kocide 2000, Kocide 2000-OOG, Kocide 3000, Kocide 3000-OOG (copper hydroxide):  broad-spectrum bactericide and fungicide. REI 48h, Group M1

Kumulus DFOG (sulfur): broad-spectrum fungicide, particularly for powder mildew. REI 24h, Group M2

Luna Experience (fluopyram + tebuconazole):  Fungal diseases on watermelon only. REI 12h, Groups 3 & 7

Luna Sensation (fluopyram + trifloxystrobin): 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 (copper + mancozeb): A broad-spectrum fungicide and bactericide. REI 48h, Groups M3 & M1

Manzate (Max, Pro-Stick) (mancozeb): A broad-spectrum fungicide. REI 24h, Group M3

MasterCop (copper sulfate pehtahydrate): A broad-spectrum fungicide and bactericide. REI 48h, Group M1

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 12h, Group 12

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

Merivon (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

Micora (mandipropamid): Oomycete fungicide labeled for greenhouse use. REI 4h, Group 40

Microthiol DisperssOG (sulfur): A protectant fungicide particularly useful for powdery mildew. May be used in greenhouse. REI 24h, Group M2

Microfine Sulfur (sulfur): A protectant fungicide particularly useful for powdery mildew. REI 24h, Group M2

Micro SulfOG (sulfur): A protectant fungicide particularly useful for powdery mildew. May be used in greenhouse. REI 24h, Group M2

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

MilStopOG (potassium bicarbonate): Powdery mildew and other foliar diseases of greenhouse crops. REI 1h, Group NC

M-PedeOG (insecticidal soap): Insecticide/fungicide labeled for greenhouse use. REI 12h

Moncoat MZ (flutolanil + mancozeb): Potato seed piece treatment for late blight. REI 24h, Groups 7 & M3

Moncut 70 DF (flutolanil): For control of soilborne fungal diseases of brassicas and potatoes. REI 12h, Group 7

Mural (azoxystrobin & benzovindiflupyr): Broad-spectrum fungicide for foliar applications for greenhouse-grown vegetable transplants grown for resale to consumers - cucurbits, fruiting vegetables, tomatoes. NOT for transplants inteneted for commercial field use. REI 12h, Group 11 and 7

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

Nevado (Iprodione): For Alternaria, Botrytis, Rhizoctonia and Stemphylium diseases; sclerotinia diseases; in beans, broccoli, carrots, crucifers, dry bulb onions, potatoes, and lettuce; white rot of garlic. REI 24h, Group 2

Nordox 75 WGOG (cuprous oxide): Copper fungicide. REI 12h, Group M1

Nu-Cop (3L, 50DFOG, 50WPOG, HBOG) (copper hydroxide): Copper fungicide. REI 48h, Group M1

Nutrol (potassium dihydrogen phosphate): Protectant fungicide for powdery mildew. REI 4h, Group 33

Nufarm T-Methyl 70WSB, 4.5F (thiophanate-methyl): A systemic fungicide with broad-spectrum control. REI (aries with crop, see label), Group 1

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

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

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

OrganocideOG (sesame oil): Powdery mildew. Group NC

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

Orondis Opti (chlorothalonil + oxathiapiprolin): Diseases of cucurbits and fruiting vegetables. REI 12h, Groups M5 & 49

Orondis Opti B (chlorothalonil): A broad-spectrum fungicide. REI 12h, Group M5

Orondis (Ultra A, Gold 200, Opti A) (oxathiapiprolin): 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

Orondis Ultra B (mandipropamid): Phytophthora diseases and downy mildew in several crops. REI 4h, Group 4

OSO 5% SC (polyoxin D): Broad spetrum fungicide for foliar and soilborne diseases. REI 4h, Group 19

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

OxiPhos (phosphorus acid + hydrogen peroxide): Preventive bioicide. REI 4h, Groups 33 & NC

Pageant 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, Groups M3

PhD (polyoxin D): Broad spetrum fungicide for foliar and soilborne diseases. REI 4h, Group 19

Phyton 35 (copper sulfate): Copper sulfate product labeled for greenhouse use on vegetable transplants. REI 48/24h, Group M1

Phostrol (phosphorus acid): A fungicide for Pythium, Phytophthora, and downy mildew. REI 4h, Group 33

Polyram 80 DF (metiram): For early and late blight in potatoes. REI 24h, Group M3

Potato Seed Treater 6% (mancozeb): Potato seed piece treatment for Fusarium dry rot. REI 24h, Groups M3

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

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

PreStopOG (Gliocladium catenulatum 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 (fluxapyroxad + pyraclostrobin): For disease control and in beans, tomato, peas, potato and corn. REI 12h, Group 7 & 11

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

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

Procure (triflumizole): Powdery mildew on brassica, cucurbits, and leafy vegetables. REI 24h, 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 33

PropiMax EC (propiconazole): Diseases of Allium species. 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, Group 11 & M5

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

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

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

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

Quilt Xcel (azoxystrobin + propiconazole): broad-spectrum fungicide for use in carrots, celery, corn, and bulb crops. REI 12h, Group 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. REI 4h, Group 33

Ranman (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 P5

Reville (phosphorus acid): Labeled for Pythium, Phytophthora, downy mildew. REI 4h, Group 33

Resist (phosphorus acid): Labeled for Pythium, Phytophthora, Fusarium, Rhizoctonia, downy mildew and silver scurf in potatoes. REI 4h, Group 33

Revus (mandipropamid): For use against downy mildew on peppers, brassica, bulb crops, cucurbits, and leafy vegetables. REI 12h, Group 40

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

Rhyme (flutriafol): Labeled for several diseases on several crops.  REI 12h, Group 3

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

Ridomil Gold Bravo SC (mefenoxam + chlorothalonil):  broad-spectrum fungicide containing 4.4% metalaxyl and 72% chlorothalonil effective against both lower and true fungi. REI 48h, Groups 4 & M5

Ridomil Gold MZ 72 (mefenoxam + mancozeb):  broad-spectrum fungicide containing 8% metalaxyl and 64% mancozeb effective against both lower and true fungi. REI 48h, Groups 4 & M3

Ridomil Gold Copper (mefenoxam + copper):  broad-spectrum fungicide containing 4.8% metalaxyl and 60% copper hydroxide effective against both lower and true fungi. REI 48h, Groups 4 & M1

RootShield AG, WPOG (Trichoderma harzianum Rifai strain KRL-AG2):  Biological treatment. REI 0h Group NC

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

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

Roper (DF, DF Rainshield) (mancozeb): A broad-spectrum fungicide. REI 24h, Groups M3

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

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

Serenade (ASOOG, OptiOG)  (Bacillus subtilis QST 713): Biological protectant fungicide. REI 4h, Group 44

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

SonataOG (Bacillus pumilus QST 2808): Biological protectant fungicide. REI 4h, Group NC

Sovran 50 WG (kresoxim-methyl): For powdery mildew and gummy stem blight in cucurbits. REI 4h, Group 11

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

Sporan EC (rosemary, clove, and thyme oils): Contact fungicide with broad crop clearance. 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, downy mildew (depending upon crops, see label). REI 4h, Group 44

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 of cole crops, curcurbits, fruiting vegetables, leafy vegetables, and bulb crops. (NOT for transplants grown for commercial field use). REI 0/48h, Group 4

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

Sulfur 6L (sulfur): For powdery mildew on many crops, rust on asparagus, and some mite pests. REI 24h, Group M6

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 (B. subtilis var. amyloliquefaciens FZB24): Biological for soilborne diseases in cucurbits, leafy vegetables, and fruiting vegetables. REI 4h, Group 44

Tanos 50 DF (famoxadone + cymoxanil): A penetrant fungicide with locally systemic and curative activities against Downy Mildew and late blight diseases. 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 12h, Group 3

Topguard (flutriafol): Cucurbits, 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, M 70 WSB) (thiophanate-methyl): A systemic fungicide with broad-spectrum control. REI (varies with crop, see label), Group 1

Torino (cyflufenamid): Powdery mildew of cucurbits and strawberries. REI 4h, Group U6

Triathlon BA (Bacillus amyloliquefaciens D747): Microbial fungicide that can be used in the greenhouse. REI 4h, Group 44

TrilogyOG (neem oil): Various fungal diseases. REI 4h, Group NC

Trionic 4SC (triflumazole): Powdery mildew and Alternaria. Also labeled for greenhouse use. REI 24h, 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. REI 48h, Group 4

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

Vivando (metrofenone): For powdery mildew. REI 12h, Group 50

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

Zampro 525SC (ametoctradin + dimethomorph):A fungicide for downy mildew and Phytophthora  diseases of potatoes and bulb, brassica, cucurbit, fruiting, 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 M3

Zing! (zoxamide): for managment of diseases of cucurbits, garlic, onions, potatoes and tomatoes. REI 12h, Groups 22 & M5

Soil Fumigation Outdoors

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 plus 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 plus 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.