Grape growers are more aware of the cost and penalty of growing vines that are infected with viral diseases. They also have a better appreciation of the necessity to carefully select healthy, clean planting material. Likewise, nurseries recognize the need to produce planting material of better quality in terms of their sanitary status. Consequently, growers and nurseries alike have started to adopt better management practices.
impact statement issue
Several grape growers in New York state and beyond brought disease issues to my attention. Knowing that viruses and viral disease can cause serious economic damage to the wine and grape industries, I addressed the disease issues by gaining a clear understanding of the problems and the route of virus infection. These insights were used to devise options for corrective actions.
impact statement response
Our 2006-2008 surveys of 95 Finger Lakes vineyards found 68 percent infected with low to high levels of grapevine leafroll viruses. One-third had high levels of infection (greater than 20 percent of infected vines). We suspect that most infections started with transmission through nursery stock. Follow-up studies found that grapevine mealybugs and soft scale insects can carry the viruses and are capable of spreading them within some vineyards. A further study of fruit composition at harvest showed fruit quality of infected vines is greatly diminished with lower sugar levels, higher pH and less crop. Our survey and outreach to the industry has raised awareness of the disease impact and prompted growers to understand that leafroll virus can spread, that infected vines produce less fruit of inferior quality, and that infected vines should be replaced. The economic impact of leafroll management is substantial. Collaborative efforts with grapevine nurseries were initiated to produce virus-free, certified vines.
impact statement summary
The primary focus of this project is to support the existing and expanding grape and wine industries in New York and other states east of the Rocky Mountains by increasing the abilities of grape producers and their advisers to manage viral infectious diseases that limit profitability and preclude sustainable production if not addressed adequately. Additionally, the project has several components that are applicable to the grape industry in the western U.S. and to those overseas. The project has three primary foci: First, extension education, synthesizing and intelligibly presenting the research-based technical information that producers and advisers need to know in order to manage their diseases efficiently, effectively, and economically; second, applied (and limited basic) research, to provide new information that will serve as the foundation for (1) designing improved management programs for traditional diseases and (2) identifying the causes of and controls for new diseases as they arise; and third, undergraduate and graduate education at Cornell's College of Agriculture and Life Sciences, to train the next generation of vineyard managers and their research/advisory community.