Use of Protective Covers to Reduce Fungicide Usages in Organic Wine Grape Production in Virginia

View the project final report

Commodities

• Fruits: grapes

Practices

• Pest Management: prevention, fruit bags to mitigate plant diseases by protection

The total acreage of certified organic grape production has increased from 12,575 acres in 1995 to 38,664 acres in 2011. Concerns on the potentially negative health impacts from consumption of conventionally produced crops are the most likely driving force of organically produced crops. However, despite the steady increase in wine grape production in Virginia, as of 2016, only three Virginia vineyards have been approved by the USDA for their organic management practices for wine grape production, and only one has a winery. In a 2008 survey conducted by the Virginia Wine Board, industry members identified sustainable production practices and organic farming systems as priority areas for state viticulture research. These research areas are important for Virginia vineyards because of the need to capitalize on the flourishing organic market, and to avoid losing market share to wine regions that have implemented organic methods.

The main reason why organic wine grape production is not common in Virginia or any other states located east of the Rockies is fungal diseases, which are driven by frequent rain events during summer months. Thus, the aim for this project was to evaluate combinations of cultivar selection and organic-approved fungicide selections. These vineyards consist of a total of nine different cultivars that are relatively resistant to fungal diseases and also have suitable characteristics for wine production. A total of four combinations of organic as well as conventional fungicide treatments can be examined each year.

The basic idea is to provide a physical barrier to prevent wetting of clusters, which is the condition for many fungal disease developments. Our proposed research is the use of paper bags or umbrella to individually protect grape clusters. These bags and umbrellas are made out of water resistant paper, designed to fit grape clusters, easily applicable with an embedded wire, with small holes for ventilation and water drain, and expected to last for a whole season. The bagging practice most likely reduces the number of fungicide and insecticide applications because once bagged, clusters are protected from water and insects.

• Determine the efficacy of paper bags and umbrellas against development of multiple fungal diseases on wine grape clusters grown with organic practices;
• Determine the timing of bagging/umbrella application for the optimal disease control;
• Examine the efficacy of fungicide-pre-coated paper bags;
• Examine economic benefits and hurdles of using individual cluster protection method.