Integrated pest management in fruits - Theory and practice

Abstract

Pest management practices used in several deciduous fruit crops are discussed. The chapter begins by noting the geographic origin and approximate date of domestication of several fruit crops and the need for more fruit breeding programs to identify and incorporate insect resistant genes into more fruit cultivars. It is assumed that fruit production probably began as small plantings where growers selected for the more pest resistant plants and later used earth-based insecticides like lead arsenate or oils to manage pest populations. After WWII, synthetic broad spectrum insecticides were developed followed by fairly rapid development of pesticide resistant insect populations. Broad spectrum pesticides eliminated many natural enemies and caused outbreaks of secondary pests like spider mites. In the last 30 years, pest management programs have become more knowledge-based and scouting intensive. More programs attempt to conserve natural enemies, delay development of pesticide resistance and be more environmentally sound (low-risk). This chapter conveys several categories of knowledge used in fruit pest management programs: fruit pest and crop agroecology; overwintering habitats; edge effect behavior; host preference; lists host resistant cultivars; shows how to derive lower and upper developmental thresholds, thermal constants, daily and cumulative degree-days (DD) after a biofix date; lists available DD models for several fruit pests; identifies two online DD calculators; lists general pest scouting guidelines and suggestions for maintaining visual and odor-based traps; and lists recommended economic thresholds for fruit pests. The next section presents four cases to illustrate various sampling programs and tactics used to manage fruit pests: (1) use of resistant rootstocks against grape phylloxera; (2) mite management program that integrates use of selective pesticides against key pests to ensure conservation of spider mite natural enemies, use of binomial or sequential sampling programs to predict the probability of biological control of spider mites, and a dynamic economic threshold for making management decisions; (3) areawide pheromone-based mating disruption of codling moths in Washington coupled with scouting to identify the need for supplemental application of low-risk insecticides; and (4) plum curculio DD model and sampling program to aid spray timing and the potential for using perimeter trees baited with aggregation pheromone and kairomone to focus plum curculio fruit damage and reduce insecticide usage. The chapter ends by identifying that recent laws and increased input costs, especially petroleum-based inputs, are causing a shift to more environmentally low-risk and sustainable fruit pest management tactics.