1988 Annual Report for LS88-001
Low-Input and Organic Pest Management for Apples and Peaches Using Mating Disruption and Ground Cover Management
Summary
In view of consumer alarm over pesticide residues on fruits, a team of scientists (led by Dan Horton and Floyd Hendrix in Georgia and Douglas Pfeiffer in Virginia) have developed alternative methods of controlling fungus diseases and insect pests. Instead of relying on heavy preventive spraying to control the fungus diseases called sooty blotch and flyspeck, these scientists have developed post-harvest techniques for dipping the fruit in a household chlorine bleach solution. The concentration of sodium hypochlorite (the active ingredient in household bleach) found to be 94% effective in removing sooty blotch from fruit (post-harvest) is 500 parts per million if the fruit is just dipped, 200 ppm if the fruit is dipped and brushed. While 94% reduction is considered successful, a dip with 940 ppm achieved a 100% reduction. The chlorine volatilizes rapidly, leaving no residue. This ingredient is exempted from food tolerances by EPA due to its low risk. In addition, a 500 ppm dip completely removed the residue of fungicides Captan and Maneb, and removed all but 0.2 ppm of Phosmet.
These scientists have also found that most major post-bloom insect pests are effectively controlled by pheromone mating disruption plus a single well-timed spray. This method involves tying to the branches of the trees hundreds of little "twisties" that emit a certain pheromone or a mating attractant, similar to the chemical given off by the female at mating time. Males become completely confused. They fly throughout the orchard trying to find the females. It disrupts the whole reproductive process, and greatly reduces the population of the pest.
In addition to mating disruption, alternate-row spraying and ground cover management help conserve natural enemies of the pests and reduce the number of sprays for peaches. The alternate row spraying technique developed for peaches resulted in 10-25% savings in spray costs.
The overall SARE pest control system developed in this study achieves equal or better control of insect and disease injury as compared with standard practices. Apple growers using the IPM/Scouting program were able to reduce spraying and pesticide costs by about 50% The number of sprays is reduced from 19 per season to an average of 9.5, thereby reducing the pest control costs from $247 per acre to $99 per acre, with no reduction in yield. Profit is significantly increasing.
Objectives
(1) To reduce spraying of apples for pest control.
(2) To implement IPM programs in peach production.
(3) Control coding moth and variegated leafroller through mating disruption achieved by pheromone permeation.
(4) Determine ground cover management practices, contrasting conventional and biological farmers, and effects on the mite system, tree growth and yield.
(5) Determine toxicity of a broad range of herbicides to Neoseiulus fallacis (Garman).
(6) Disseminate to conventional and organic growers the current information on reduced pesticide input and organic pest management systems.
(7) Develop new methods for controlling pests using reduced input and organic techniques.
Resource Development
The researchers have published 11 articles or book chapters on pest management for peaches and apples. Over 2600 farmers have been introduced to and adopted the developed IPM techniques presented at workshops or conferences.