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 advocates integration of multiple control strategies to achieve long-term pest management solutions.

IPM consists of gathering information, interpreting data, creating a flexible management plan, making timely decisions and taking the proper action. Information gathering and decision-making techniques include: accurate pest identification, learning about the weak link in a pest's life-cycle or biology, scouting and monitoring crops in fields and greenhouses, using action thresholds to minimize spraying, and keeping records of findings to assess the effectiveness of management decisions.

  • Accurate pest identification is a crucial first step on the road to a solution. Misidentification of pests is a common cause of pest control failure and crop damage. See the "Diagnostics" section and photo supplement for help with identification.
  • The biology and life-cycle of a pest often reveals the key to successful control measures. Detailed, pest-specific information is available in fact sheets on IPM web sites or publications listed in the References for Commercial Vegetable Growers section. See also specific pest listings in this Guide.
  • Scouting involves using systematic methods of inspecting the crops on a regular basis to quantify pest populations or crop injury/damage. Scouting techniques vary considerably 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 conditions or trapping pests 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).
  • Action thresholds are usually expressed as a fixed number for individual pests (i.e., 7 moths/week or 2 weeds/foot of row) or crop injury (i.e., 20% defoliation), or as a rating for weather conditions (i.e., 15 Disease Severity Units). Thresholds tell you when to control the pest(s) to prevent or minimize economic damage to crops. 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.
  • Proper record-keeping involves recording data on weather, pest populations, crop conditions and control procedures all season. Good records help determine which pest control strategies are working and where improvements should be made in the future.

Along with information gathering and decision-making techniques, a variety of preventative and curative control methods are used to construct a complete IPM management plan for each pest, crop and farm. Cultural, mechanical, physical, genetic, and biological controls help prevent severe pest problems, while pesticides are used when additional control measures are required.

  • Cultural controls are modifications of the crop production systems that suppress pest populations and occurrence. A few examples include: the use of better site selection, crop rotation, modifying planting times or plant spacing, improved water and nutrient management for better crop health or to limit weed competition, breaking up plow pans, cleaning soil from 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, cultivation, flaming, plastic or organic mulches, row covers, greenhouse ventilation, washing, cold storage and roguing infected plants.
  • Genetic controls are generally achieved through traditional breeding programs which select crop varieties with resistance or tolerance to insects, nematodes or diseases or with plant growth characteristics which favor plant success (such as rapid emergence, heat or cold tolerance, canopy or leaf traits). Biotechnology (genetic engineering) 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).
  • 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: beneficial 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 range from parasitic wasps, entomophagus and competitive fungi and bacteria, to predacious bugs, beetles and spiders. Natural enemies of pests exist everywhere in nature and should be preserved whenever possible. Many beneficials 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 beneficials. 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 list of publications in the References for Commercial Vegetable Growers section, or visit your local Extension System's IPM web site.