Mary E. Barbercheck, Penn State University
The goal of Integrated Pest Management (IPM) is to control populations of pests below levels that result in economic damage. Ideally, this is achieved through the integration of all suitable control techniques in a compatible manner. The success of IPM in non-organic production systems is often due to a ready arsenal of efficacious synthetic chemical pesticides. Indeed, many of the IPM systems developed for non-organic crops are based on the pre-emptive use of pest control materials (e.g., genetically modified crops, insecticidal seed treatments) or assessment of pest populations and reaction to them with the use of “therapeutic” materials (chemical or biological) in a timely, but reactive way.
Colorado potato beetle adults. Photo credit: Jim Riddle, University of Minnesota
In contrast, organic farming systems rely on ecologically-based practices such as cultural and biological pest management, and virtually exclude the use of synthetic chemicals in crop production. Genetically modified crops are not allowed. Under organic farming systems, the fundamental components and natural processes of ecosystems, such as soil organism activities, nutrient cycling, and species distribution and competition, are used directly and indirectly as farm management tools and to prevent pest populations from reaching economically-damaging levels. For example, crops are rotated, planting and harvesting dates are carefully planned, and habitats that supply resources for beneficial organisms are provided. Soil fertility and crop nutrients are managed through tillage and cultivation practices, crop rotations, cover crops, and supplemented with manure, composts, crop waste material, and other allowed substances.
Black Vine Weevil. Photo credit: Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org
In organic systems, the goal is to design the production system so that pests do not find plants, are controlled by natural enemies (biological control), or their damage is kept to a minimum. Vigorous, healthy plants are more able to withstand damage caused by arthropods and disease. Therefore, a “plant positive” (as opposed to “pest negative”) approach of managing the system for beneficial processes and cycles and creating healthy soil and plants, is at the foundation of integrated pest management in organic systems.