Integrated Pest Management

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.

• Accurate pest identification is critical; misidentification of pests is a common cause of pest control failure and crop damage. See Diagnostics for Plant Problems and the Northeast Vegetable & Strawberry Pest Identification Guide for help. There are also many excellent online resources.
• Biology and life-cycle of pests reveal vulnerable stages for successful control measures. Detailed, pest-specific information is available in fact sheets on Extension web sites or publications listed in the Additional Resources section. See also specific pest listings in this guide.
• Scouting is systematic, regular inspection of crops to quantify pest populations or crop injury. Scouting techniques vary depending upon the type of pests (weed, insect, disease, or other) involved and the crop life stage. Details are available in pest and crop-specific sections in this guide.
• Monitoring weather and pest trends can be used to assess or predict current or future pest problems and help to prevent crop damage. Equipment and procedures vary by pest. Disease forecasting and insect development models for local conditions in many states can be accessed at www.newa.cornell.edu.
• Action thresholds. When pest numbers exceed research-based thresholds, active control measures are recommended to prevent or minimize economic loss. Such results may be expressed, for example, as 7 moths/week, 2 weeds/foot of row, 20% defoliation, or as a rating of weather conditions, e.g. "15 Disease Severity Units.” Some thresholds are given for pests in the individual crop sections in this manual and others vary by state, region, or are determined by market tolerance. Contact your state's Extension IPM personnel for local action thresholds.
• Regular recordkeeping. Good records help determine which pest control strategies are working and where improvements should be made in the future. Try to keep track of scouting results, crop conditions, and control procedures all season.

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.

• Cultural controls involve modifying crop production systems to make conditions unsuitable for pests. Examples include: appropriate site selection, crop rotation, modification of planting times or spacing, precision water and nutrient management, weed control to improve air circulation, subsoiling to improve drainage, sanitizing machinery between fields, and cover cropping.
• Mechanical and physical controls consist of changing the environmental conditions to disrupt pest life cycles and/or suppress populations. Temperature, light, humidity, and other factors can be modified using a variety of equipment and supplies. Mechanical and physical controls function by cutting, crushing, burying, or excluding pests with implements and barriers, as well as by heating, cooling, drying, wetting, or regulating light. Some examples include: the use of hot water-treated seed, plowing to bury infected crop residue, cultivation or flaming for weed control, plastic or organic mulches for weed suppression, row covers to accelerate crop growth and exclude pests, greenhouse ventilation, washing produce and equipment, cold storage, and roguing out infected plants.
• Breeding for resistance is a process of selecting for crop varieties that are resistant or tolerant to pests, including pathogens, insects, and nematodes. Some breeding has been done to favor growth characteristics that enable plants to withstand disease pressure (such as rapid emergence, heat or cold tolerance, canopy or leaf traits). Recombinant DNA technology (“genetic modification”) has been used in a few vegetable crops to achieve resistance by incorporating traits from non-related organisms; examples are virus resistance in summer squash and caterpillar resistance in sweet corn (through expression of the Bt protein toxin in plant tissues). At this time, these are the only genetically modified vegetables available for market production.
• Biological control, also know as biocontrol, is the use of naturally occurring or introduced beneficial organisms to control or suppress pest populations. Biological control agents include insects, mites, spiders, birds, nematodes, fungi, bacteria, viruses, protozoa, and plants. Common examples are parasitic wasps, entomopathogenic fungi, bacteria, nematodes, and predaceous bugs, beetles, and spiders. Conservation biological control is the modification of habitat or management practices to protect, attract, and enhance existing natural enemies of pests in the environment. For instance, growing native perennials near crops and reducing the use of broad-spectrum insecticides can support natural enemy populations, strengthening pest suppression. Many biocontrol agents can be purchased for augmentative biological control, wherein natural enemies are released  to control pests in the greenhouse and/or for specific crops.

Pesticides should be used in conjunction with previously described control measures and only when pest population densities will cause economic damage or environmental conditions favor disease. Some products, known as biorational pesticides, have attributes that reduce their risk to the user and the environment (see Biorational and Organic Pesticide section). For example, selective insecticides are designed to primarily target specific pests with reduced harm to beneficial organisms. On the other hand, broad-spectrum insecticides harm a wide range of pests and beneficial organisms. Loss of biocontrols can often lead to resurgence of primary pest populations or outbreaks of a secondary pest, and additional applications may become necessary. By sparing biological control agents, selective insecticides decrease the risk of secondary pest outbreaks, reduce the impact on the environment, improve farm safety, and minimize the number of applications needed. If the use of a pesticide is required, choose a selective product or another biorational pesticide when possible. Broad-spectrum insecticides should only be used if no other viable options exist to manage the pest. Repeated use of a single group of pesticides in succession can increase the tolerance of a target pest to that pesticide group’s mode of action. Rotate between groups to hinder the development of pesticide resistance and preserve the longevity of available products. Always read and follow the directions provided on pesticide labels to maximize effectiveness, minimize risks associated with that product, and comply with federal law. 

Although, 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 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.