Overview: 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 scheduled, 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 important; misidentification of pests is a common cause of pest control failure and crop damage. See the "Diagnostics" section and Northeast Vegetable & Strawberry Pest Identification Guide for help. There are also many excellent on-line resources.
  • Biology and life-cycle of  pests reveal vulnerable stages for successful control measures. Detailed, pest-specific information is available in fact sheets on IPM web sites or publications listed in the References and 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. Details are available in pest and crop-specific IPM fact sheets and manuals, and in pest listings in this Guide.
  • Monitoring weather trends and trap catches can be used to assess or predict current or future pest problems and help to prevent crop damage. Equipment and procedures vary by pest (for details see references mentioned above). Disease forecasting and insect development models for local conditions in many states can also be accessed at www.NEWA.cornell.edu.
  • Action thresholds. When systematic scouting documents pest numbers in excess of 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, or 20% defoliation, or as a rating for weather conditions like "15 Disease Severity Units.”  Some thresholds are given for pests in the individual crop sections in this manual and others vary by state or region. Contact your state's Extension IPM personnel for local action thresholds.
  • Regular record-keeping. 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 are modifications of the crop production systems that create unsuitable conditions for pests. Examples include: appropriate site selection; crop rotation modification of planting times or spacing; precision water and nutrient management for better crop health; weed control to improve air circulation; subsoiling to improve drainage; sanitization of machinery between fields; and the use of cover and smother crops.
  • Mechanical and physical controls consist of using supplies, equipment, or some factor, such as temperature, humidity or light, to disrupt pest life cycles and/or suppress populations. Mechanical and physical controls function by cutting, crushing, burying or excluding pests with implements and barriers, or by heating, cooling, drying, wetting, or regulating light in some way. 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; cold storage; and roguing infected plants.
  • Breeding for resistance is a process of selecting for crop varieties that are resistant or tolerant to pathogenic microorganisms. There has also been breeding for insect and nematode resistance. 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 is the use of naturally occurring or introduced beneficial organisms to control or suppress pest populations. Biological control agents come in all shapes and forms including: insects, mites, spiders, nematodes, fungi, bacteria, viruses, protozoa and plants. In the broadest interpretation, they would include things like microbial pesticides and the use of trap crops. Common examples are parasitic wasps, entomophagus and competitive fungi and bacteria, predacious bugs, beetles and spiders. Natural enemies of pests exist everywhere in nature and should be conserved whenever possible. Many biocontrol organisms can be purchased for use in the greenhouse or for specific crops.
  • Pesticides should be used in conjunction with the control measures previously mentioned and only when pest population densities will cause economic damage, or when environmental conditions favor disease. Selective insecticides are products that primarily target the pest(s) you wish to control, with few or no detrimental effects on most beneficial organisms. They may also have other attributes making them less harmful to the user and the environment and may be lumped into a larger category of Biorational pesticides (see Biorational Pesticide section). If the use of a pesticide is required, choose a selective product or another biorational pesticide if possible. Selective insecticides usually spare biological control agents, reduce the risk of secondary pest outbreaks, reduce the impact on the environment, improve farm safety, and minimize the number of applications needed. Broad-spectrum insecticides usually kill many different kinds of pests and beneficial organisms. The use of broad-spectrum insecticides can often lead to resurgence of primary pest populations due to a lack of natural controls, or to secondary pest outbreaks and additional applications. Broad-spectrum insecticides should only be used if no other viable options exist to manage the pest. Proper pesticide application and resistance management techniques should be used to maximize the effectiveness and preserve the useful life of the available products.

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, see the References and Resources section, or 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 certifiably 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 certain key pest species and disease propagules. It may also affect neighboring farms by providing a sanctuary for local pest populations.