Nematode Management With and Without Nematicides: Opportunities and Challenges

Integrated fruit production (IFP) offers an alternative to the chemically intensive, conventional pear production system. In 1994, we began a 4-year project supported by the Hood River Grower Shipper Association (HRGSA) together with Oregon's Center for Applied Agricultural Research (CAAR) to demonstrate to the industry how to bring about changes in orchard management practices, particularly as they apply to pest and disease control on pears. Several criteria guided us in designing the pest management programs for the IFP blocks and contrasting them with conventional pest control programs. We emphasized the use of selective control methods to encourage biological control; we avoided toxicity class I pesticides to create a safer orchard environment; and we alternated control tactics with different modes of action as a resistance management strategy. Controls were applied only if needed; for example, when monitoring indicated that pest populations exceeded economic threshold levels. Selective codling moth control was achieved with mating disruption using lsomate-C Plus pheromone dispensers in all four IFP blocks to create an orchard environment that was more conducive to biological control. Pear psylla control consisted of sulfur plus oil and Comply (fenoxycarb) in the prebloom period, followed, if needed, by soap sprays or low rates of AgriMek (abamectin) after bloom. A diverse complex of natural enemies was present and helped to regulate pear psylla. Selective acaricides (e.g., low rates of Vendex {fenbutatin}, Savey {hexythiazox}, oil) were applied when mites built up during the foliar season. Control with the IFP program was at least as good as with the conventional program, where broad-spectrum pesticides provided most of the pest control. The pest management program in the IFP blocks was somewhat more expensive, in large part due to the high costs of mating disruption. Fruit from the IFP blocks stored and ripened as well as fruit from the conventional blocks. The project demonstrated that pear growers can switch successfully to pest management programs where organophosphate 43 and other broad-spectrum pesticides are replaced by available alternative controls without loss in