Growers of pickling cucumbers and other crops susceptible to infection by downy mildew may someday benefit from higher yields and lower production costs thanks to collaborative research by Clemson University’s School of Agricultural, Forest and Environmental Sciences (SAFES) and North Carolina State University.
Anthony P. Keinath, professor of plant pathology in SAFES was recently awarded a $40,000 grant from the United States Department of Agriculture (USDA) to develop a model for predicting downy mildew infection risk to cucurbits, a family of plants that includes various squashes, melons and gourds. Keinath ‘s research will be part of a wider study being conducted by N.C. State and funded by a $180,000 USDA grant.
“If we can understand the weather factors that lead to a high risk of downy mildew infection, then we can reduce the need for fungicides, reduce the cost of cucurbit crop production, and increase yield,” Keinath said.
Keinath and his collaborators hope to quantify the effects of weather variables such as temperature, humidity, rainfall, dew point and cloud cover on the risk of infection. They also hope to validate the current cucurbit downy mildew forecasting system that is composed of 25 collaborating institutions in the Eastern United States, California and Ontario, Canada reporting weather and other factors to a central online database.
Currently, growers of cucurbit crops such as pickling cucumbers and cantaloupes must spray costly fungicides in order to protect their crops from infection. In Michigan, the largest U.S. producer of pickling cucumbers, fungicide sprays cost farmers a total of $6 million.
Downy mildew also contributes to a decrease in production of pickling cucumbers in South Carolina. Keinath’s research has shown a 68 to 90-percent loss of yield due to infection, which would mean $900,000 in potential losses to South Carolina pickle growers. A 2004 epidemic of downy mildew infection caused U.S. growers an estimated $20 million in lost yield.