University of California

BIOS approach tested for controlling walnut pests in San Joaquin Valley


Joseph A. Grant
Walt Bentley
Carolyn Pickel
Jeannine Groh-Lowrimore

Authors Affiliations

J.A. Grant is Farm Advisor, UC Cooperative Extension (UCCE), Stockton; W. Bentley is IPM Entomologist, UC Kearney Agricultural Center, Parlier; C. Pickel is Area IPM Advisor, UCCE, Yuba City; J. Groh-Lowrimore is Staff Research Associate, UCCE, Stockton. The UC Sustainable Agriculture Research and Education Program funded this project. The authors wish to thank project growers for their vision and cooperation and CAFF for inspiring it.

Publication Information

Hilgardia 57(3):86-92. DOI:10.3733/ca.v057n03p86. July 2003.

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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.


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Grant J, Bentley W, Pickel C, Groh-Lowrimore J. 2003. BIOS approach tested for controlling walnut pests in San Joaquin Valley. Hilgardia 57(3):86-92. DOI:10.3733/ca.v057n03p86
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