Farm Ecosystem - Management Factors Contributing to Pest Suppression on Organic - Conventional Vegetable Farms

Farm Ecosystem - Management Factors Contributing to Pest Suppression on Organic - Conventional Vegetable Farms

Summary

Summary
Organic farmers report a reduction in pest pressure after a number of years of organic production. Our goal in this project is to identify and quantify relationships between farm management practices, soil quality, and pest populations on mixed-vegetable farms. We sampled extensively in potatoes and winter squash on four organic and four conventional farms throughout New York to characterize crop management practices, pest and beneficial complexes, a variety of soil characteristics, weed species and density, and field border flora and fauna. We will also conduct educational programs for organic vegetable grower, and research and demonstrate pest management materials and practices approved for organic production.

Objectives
Explore the relationships between farm management practices, soil quality, farm landscape, and pest populations in two vegetable crops on organic and conventional farms. Estimate the costs of production for the two crops on each cooperating farm.

Develop and present educational programs for organic vegetable growers.

Research and demonstrate new or unfamiliar pest management techniques and products allowable on certified organic farms.

Methods
Extensive sampling was conducted in potato and winter squash fields on four organic and four conventional mixed-vegetable farms. Farmers were interviewed prior to the growing season to determine the five-year rotation history and detailed two-year production history of the fields that would be planted to squash and potatoes in 2000, their equipment inventory, and marketing channels. Growers maintained logs of all activities associated with their potato and winter squash crops during the growing and marketing season. These logs will be used to estimate costs of production for each crop on each farm.

Each field was divided into six sampling areas of approximately equal size. Insect and disease pests and beneficial insects were sampled weekly in each of the six areas of the field. Beneficial insects were also sampled using sticky-card and pitfall traps, and by rearing parasitoids from Colorado potato beetle and striped cucumber beetle collected twice per season from each field. Soil analyses consisted of a standard soil test, nitrate, ammonium, organic carbon, nitrogen mineralization rate, microbial activity, nematode populations, and a disease suppressiveness bioassay. Plant samples included tissue samples taken at the time of maximum crop growth, and yield estimates, percent soluble solids for squash and specific gravity for potato, and disease or insect damage at harvest.

Results
Data analysis is just beginning. The data set is being compiled, and consultations with our collaborating statistician will begin as soon as it is complete.

Impacts and Potential Contributions
We hope that analysis of the field data will show relationships between pest populations and farm management practices that improve soil quality and farmscape diversity. The relationships that we discover will benefit new organic growers, who are working to establish those relationships, as well as conventional growers, who may be able to benefit from selective adoption of practices that improve soil quality even if they choose not to adopt the entire set of organic practices.

Organic growers have not had the full benefit of interpretation and dissemination of applicable research results that Cooperative Extension routinely provides conventional growers. Articles, efficacy trials, and reports from on-farm demonstrations generated during this project will help address that situation. The educational programs planned for the winter of 2001 will provide a solid foundation in the basic concepts and practices of organic vegetable production for new organic farmers.

A number of new Organic Materials Review Institute (OMRI) approved botanical and microbial pest-management products have come onto the market in the past few years. Testing them in university efficacy trials will provide farmers with the information they need to use them effectively. On-farm demonstrations and associated field days will allow growers to see firsthand how new products and practices work.

Reported November 2000

Collaborators: