Disease Susceptibility in Cold- Climate Grape Cultivars of the North Central Region

View the project final report

Commodities

• Fruits: grapes

Practices

• Pest Management: integrated pest management

The wine grape industry in the North Central Region (NCR) has expanded substantially in the last 15 years as new cold-hardy varieties have become available. Wine grapes are now among the most widely planted new fruit crops in NCR, and account for approximately2400 hectares and 401 million dollars annually as an industry. The rapid expansion of the industry means that several central knowledge bases are still catching up, including an unbiased, research-based assessment of the relative susceptibility of these new cold-climate hybrids to important grape diseases. The current lack of knowledge is leading to confusion, over spraying, and poor Integrated Pest Management. My project will take a new, in-field approach to generating susceptibility data. Two vineyards containing commercially popular cultivars will be left unsprayed by fungicides for two full growing seasons. Both vineyards will be scouted and rated for disease every week from bud break through fall leaf drop. These data will complement and be compared with disease data collected on potted grape plants placed in the vineyard to pick up vineyard inoculum and then moved to a high humidity environment to encourage disease development. The information from these two data sets will allow for the creation of a more accurate, unbiased disease susceptibility chart that can be distributed to growers through web sites (e.g, eXtension), meetings, and yearly spray guides. The project will be evaluated by peer reviewers of journal articles and grape growers at extension events.

This project will provide farmers with accurate and up to date information regarding disease susceptibility of their cold-climate wine grapes. Knowledge of cultivar susceptibility will lead to better-informed cultivar selection and allow for reduced pesticide use where resistance is found. Effective Integrated Pest Management in cold-climate grapes is still developing, and an increased awareness of disease risk on a cultivar specific basis will allow for heightened awareness in spraying and an increase in cultural control through the planting of more resistant cultivars. It will also promote avoidance of highly susceptible cultivars, reducing chemical inputs and pesticide residue on the fruit and on the land. This information will also aid certified organic growers who are seeking to establish vineyards that will minimize the need for intensive spraying. Cold climate grape cultivars are not generally sprayed differentially by most growers, and are instead sprayed in a pre-scheduled format. This study will help change this practice by providing research-based information on a cultivar-specific basis. Ultimately, this work will aim to help replace scheduled sprays with cultural control, moving toward less chemical intensive, more sustainable viticulture in the North Central Region as a whole.