Wine production in Maryland, Virginia and North Carolina combined represents an estimated $16 billion industry. This research protects and bolsters that burgeoning industry by addressing fungal diseases like ripe rot, which causes the grapes to rot on the vine before they are ready for harvest, and reducing fungicide use in the region’s vineyards.
Understanding & Preventing Ripe Rot
Since ripe rot does not impact drier wine grape growing regions, where research investments are generally focused, mid-Atlantic growers were unsure what causes the disease or how to effectively prevent it. To address the problem, researchers evaluated conditions in which ripe rot infects grapes grown in the humid mid-Atlantic region, fungicides that effectively combat the pathogen and the optimal timing for applying these fungicides. The research team also identified mechanisms for sharing this information with growers.
Identifying the Ripe Rot Pathogen & Management Practices
University of Maryland researchers identified the pathogen responsible for ripe rot and developed an improved ripe rot management practice, as well as a public disease risk model, GrapeCast, which accounts for weather patterns, leaf wetness and crop infection susceptibility to estimate the number and timing of fungicide sprays for grapevine ripe rot. Extension networks and influential vineyard consultants were engaged to widely promote these tools, which have been adopted on thousands of acres in the mid-Atlantic.
Grape growers in the mid-Atlantic have reduced their annual
losses by an estimated $7 million over four growing seasons due to this research. Additionally, with targeted fungicide use, growers are using less fungicides, lowering the chance of fungi developing resistance to these control measures. VineSmith, a widely used decision-making tool for wine grape growers east of the Rocky Mountains, incorporated the improved fungicide guides in its WineGrape Spray Guide. A New York apple orchard is also using the risk model developed by this research to inform timing of fungicide
applications.