BIOS approach tested for controlling walnut pests in San Joaquin Valley

As concerns increase over changes in pesticide regulations, farmworker safety, surface and groundwater contamination and escalating costs and uncertainties associated with chemical controls, walnut growers need effective and cost-efficient ways to produce walnuts with minimal use of pesticides. This study compared the effectiveness of Biologically Integrated Orchard Systems (BIOS) with conventionally managed walnut orchards in the northern San Joaquin Valley from 1999 to 2001. We found no significant differences between BIOS and conventional blocks in nut quality or yields. Codling moth was effectively controlled by pheromone disruption and alternative pest-control methods. Mating disruption, by itself, appears to provide good control of codling moth in many orchards. However, it is still more expensive for growers than conventional pest-control methods

Pheromones control oriental fruit moth and peach twig borer in cling peaches

Slow-release pheromone tech-nology can successfully control oriental fruit moth and peach twig borer while eliminating in-season insecticide sprays in cling peaches. In conjunction with a demon-stration program, we compared mating disruption for these two pests with standard grower pest-control methods in the Sacramento and San Joaquin valleys, and monitored for pest damage, yield and grower costs. While the mating-disruption program was effective in controlling the targeted pests, costs were higher and growers preferred a partial disruption program that included some supplemental late-season insecticide sprays. Subsequently, we developed monitoring methods to determine the need for supple-mental sprays. This partial mating-disruption program still costs about $60 more per acre than a standard spray program. Predicting efficacy and determining the need for supplement sprays is also more difficult with the partial program than with the pheromone-based control program

Pheromone-based pest management can be cost-effective for walnut growers

Many organophosphate and pyrethroid insecticides currently used by California walnut growers have been linked to negative environmental or human health impacts, increasing the probability of use restrictions and phase-outs. We assessed the acceptability of alternative reduced-risk strategies by comparing their costs to those of pest management programs currently in use among San Joaquin County walnut growers. To do this, we analyzed data from the California Department of Pesticide Regulation's legally mandated Pesticide Use Reports on actual pesticide applications for 3 years, from 2002 to 2004. While many factors other than cost influence growers’ pest management choices, we found that alternative strategies can be cost-competitive with conventional approaches, depending on the pest pressure and savings due to reductions in secondary pest outbreaks