Screening Potato Varieties Commonly Grown by Organic Farmers for Susceptibility to Damage and Yield Reduction Caused by Potato Leafhopper

View the project final report

Commodities

• Agronomic: potatoes

Practices

• Pest Management: genetic resistance

Potatoes are an important crop for organic vegetable growers, but potato yields on organic farms were 25-60% lower than on conventional farms in a study conducted between 2000 and 2002. In our preliminary data analysis from this study higher potato leafhopper populations appear to be one factor correlated with lower yields on the organic farms. Organically approved insecticides for potato leafhopper management are limited and their effective use may be difficult to implement on smaller mixed vegetable farms. Currently, only anecdotal information exists about the relative susceptibility of potato varieties commonly grown by organic farmers to damage and yield reduction caused by potato leafhopper. The work proposed here will provide growers with quantitative information on potential yield reductions caused by potato leafhopper. It will also provide important information for future trials seeking to determine if potato leafhopper resistant varieties intercropped with susceptible varieties can help reduce potato leafhopper damage on the susceptible varieties.

Our short-term goal, and the subject of this proposal, is to determine the relative susceptibility of ten potato varieties most commonly grown by organic growers to damage and yield reduction caused by potato leafhopper. Currently there is anecdotal information on what varieties are particularly susceptible, but no quantitative comparisons. We recently sent out a survey to certified organic growers in New York, the New England states, and Pennsylvania to determine the most commonly grown varieties as well as the most important insect and disease pests these growers are facing. The information generated in the proposed trial will be immediately useful for organic growers to help them stabilize their yields, and will provide important information for a longer-term project for which we will seek funding from other sources.