Enhancing biological control in mating disruption pear orchards by understory management

Project Overview

Project Type: Research and Education
Funds awarded in 1999: $110,497.00
Projected End Date: 12/31/2001
Matching Non-Federal Funds: $21,757.00
Grant Recipient: USDA-ARS
Region: Western
State: Washington
Principal Investigator:

Annual Reports


  • Fruits: pears, general tree fruits


  • Crop Production: cover crops, intercropping
  • Education and Training: demonstration, on-farm/ranch research
  • Natural Resources/Environment: biodiversity
  • Pest Management: biological control, biorational pesticides, integrated pest management, mating disruption, row covers (for pests), weed ecology
  • Production Systems: agroecosystems


    Effects of mowing frequency on densities of natural enemies and select pests in the soil, in the ground cover, on the orchard floor, and in the tree canopy was documented at 3 reduced-pesticide pear orchards. Densities of natural enemies and prey in the ground cover increased dramatically with reduced frequency of mowing. The effects translated into higher densities of some natural enemy taxa in the soil and, more importantly, in the tree canopy. Parasitism rates of codling moth and pear psylla were unaffected by mowing regime, although low rates of parasitism in all treatments may have obscured effects.

    Project objectives:

    1. Determine the effects of mowing frequency on insect densities in the ground cover, in the soil, on the orchard floor, and in the tree canopy in mating disruption pear orchards, emphasizing effects on biological control organisms and their prey;

    2. Quantify natural enemy impact in different mowing regimes by estimating parasitism rates of pear psylla, codling moth, and leafminer;

    3. Present project at annual Field Days.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.