Concepts of IPM

Craig Hollingsworth
Revised: 
March 2017

“Integrated pest management (IPM) is an ecologically-based pest control strategy that relies heavily on natural mortality factors such as natural enemies and weather, and seeks out control tactics that disrupt these factors as little as possible. IPM uses pesticides, but only after systematic monitoring of pest populations and natural control factors indicate a need. Ideally, an integrated pest management program considers all available pest control actions—including no action—and evaluates the potential interaction among various control tactics, cultural practices, weather, other pests, and the crop to be protected.” 1

While dozens of definitions have been proposed for IPM (see: http://ipmnet.org/IPMdefinitions/ ), the definition above has been widely accepted by the agricultural community for 30 years. In particular, it points to IPM’s ecological foundation and to the importance of monitoring and selection of multiple control practices.

Most of the benefits of implementing IPM are centered on the reduction of pesticide use. Fewer pesticide applications result in savings for materials and application costs. Environmental contamination and worker health problems can also be reduced, and energy for the manufacture and application of pesticides is conserved. Pesticide reduction reduces the development of pesticide resistance and results in stronger natural enemy populations reducing the likelihood of pest outbreaks.

Depending on the complexity of the management system, an IPM program may target a single pest, a pest category (e.g. insects, weeds, diseases or rodents) or the whole pest complex. While traditional pest control considers each pest exclusively, IPM takes into account the interactions among pests, beneficial organisms, the environment, and the crop.

Development of an IPM system requires a thorough understanding of the biology of the crop (or resource) and of the pest complex. The IPM concept was developed from the realization that most pesticide applications affect both pests and beneficial organisms in the crop, sometimes to the disadvantage of the grower.

An IPM system attempts to maintain pest populations below economically damaging levels by using a balance of biological, cultural, chemical, genetic, and other control methods. IPM systems are flexible and programs may vary with time of year, location, and type of crop. Many books, manuals and websites are devoted to discussions of general IPM principles and to the application of IPM to specific agricultural and urban systems. However, the following components are generally found in IPM programs:

  1. Management units Monitoring is conducted with the aim of providing results for the management of a specific management unit – the part of the system that will receive the same pest control decisions. The unit may be part of a field, a single field or several fields. Chemical control decisions are sometimes based on the area that can be covered by a single spray tank.
  2. Key pests An IPM program targets specific pests, which may include insects, mites, plant diseases, weeds or vertebrates. In the development of an IPM program, these pests are identified and monitoring and control programs are designed for each of these pests.
  3. Monitoring Sampling should accurately assess the pest pressure and the abundance of beneficial organisms in the management unit. Monitoring is conducted so that management actions can take place in a timely and effective manner.
  4. Pest action thresholds. Keeping fields entirely pest free is neither necessary nor desirable. Most crops can tolerate low pest infestation levels without any yield loss. IPM seeks to reduce pest numbers below economically damaging levels rather than eliminate infestations. Pesticides should be applied only when economically justified by the numbers of pests present.
  5. Use of multiple controls and tactics Control tactics should be employed to make the crop less favorable for pest survival and reproduction, while disturbing the rest of the ecosystem as little as possible. Combining different control tactics into an overall strategy balances the strengths of each against any individual weaknesses. Using different techniques also reduces the probability of the development of pest resistance. Control tactics should be compatible with beneficial organisms and the environment.

Developing or implementing an IPM program for a crop involves a systematic application of knowledge about the crop and the pests involved. The following sources may be useful in acquiring and applying that knowledge:

1 Flint, M. L. and R. Van den Bosch. 1981. Introduction to Integrated Pest Management. Plenum Press.