Pesticides are necessary to produce food crops that are widely available geographically and temporally, that are in ample supply, and that can be bought at a reasonable price. Pesticides improve food quality, safety and availability. Produce and products damaged by insects and diseases are more prone to postharvest decay. Pesticides are labelled by class.
Producers often have a choice between several different modes of pest control .
Cost, environmental factors, harvest delay, severity of infestation, and other factors determine which chemistry is most useful. In evaluating the application for registration, data concerning toxicity, environmental persistence, residues on fresh and in processed foods, efficacy and other factors are considered. The process of accumulating these data is a multi-million dollar process, and can only be justified for products that are highly effective and can be used on large acreages. A special research collaboration between USDA and university scientists has been formed to assist in the registration process for minor use chemicals, the IR-4 Project. The restricted use pesticides require certification for purchase and application.