Managing grapevine diseases CALS Impact Statement

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 advisors to manage 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 in overseas locations. The project has three primary foci. First, Extension education, synthesizing and intelligibly presenting the research-based technical information that producers and advisors 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 (i) designing improved management programs for traditional diseases, and (ii) 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.

Although grapes have been cultivated in New York and other eastern states for over two centuries, the industry has traditionally focused on species of vines native to this region. However, demand for such varieties (e.g., Concord, Catawba, Niagara) has decreased steadily in recent years, resulting in lower prices and the need to minimize all production costs, including those for disease management. In contrast, demand and prices for premium wine grapes have increased steadily, driven by the rapid expansion of local wine industries and associated agritourism. However, premium wine grape varieties (e.g., Chardonnay, Riesling, Pinot Noir) derive primarily from a single grape species native to Europe, and such varieties have little resistance to the major disease organisms native to our region. Thus, traditional disease management programs developed for native American varieties are not only biologically inadequate for premium wine grapes, but the consequences of poor control on the latter are magnified by their increased value. Furthermore, many new producers of these premium varieties have no farm background and/or little to no experience with disease control on a high-value crop. Therefore, this project has been undertaken to (i) help producers of native varieties decrease their production costs while maintaining adequate disease control; and (ii) develop appropriate management programs for high-value wine grapes along with educational programs for their implementation.

Research projects were implemented to study the biology and management of the major fungal, viral, and bacterial disease common throughout the eastern and midwestern states. Specific areas of research focused largely on the applied biology and integrated management of these diseases, with two primary emphases: (1) how climate, grapevine physiology, and viticultural practices impact their development and management; and (2) the activities of important fungicides and biological control agents used for grape disease control, in order to maximize the efficiency of their use and thereby minimize their associated economic and environmental costs. Additionally, more basic research was initiated to understand the mechanisms of pathogen behavior and the potential for disease control through non-chemical approaches, including non-traditional breeding. Growers and advisors received regular educational programming through a variety of oral presentations, printed and electronic media, and in-person consultations; in 2007, this included 24 oral presentations to over 2,500 individuals and 14 written publications. Since 2005, oral presentations have been made to stakeholders throughout all New York production regions and in 12 additional states and five foreign countries, often by invitation. A new undergraduate course, Grape Pest Management, was initiated in 2006 and expanded in 2007, to instruct the next generation of vineyard managers and their research/advisory support community.

Supported by the results of our research and extension programs, producers of native grape varieties have typically reduced their annual fungicide sprays from five down to two over the past 10-15 years, resulting in an annual savings of approximately $1.8 million across the 20,000 acres of these grapes in New York alone. Because high-value wine grapes have only a short history of production in most regions, similar comparisons are difficult to make. Nevertheless, a typical annual cost for disease control in these vineyards has been estimated at nearly $500 per acre, and the cost of a poorly-controlled, ubiquitous disease such as powdery mildew is approximately $6,000 per acre (complete loss of 4 tons/acre x $1,500/ton). Assuming a 10 percent reduction in costs resulting from the increased efficiencies attributable to our research and education programs, NY growers have saved approximately $250,000 per year in direct control across the 5,000 acres of the state’s premium wine grapes. Furthermore, an assumption that our efforts have resulted in a mere 5 percent annual reduction in fruit lost to disease provides additional savings of approximately $1.1 million in farmgate value, and up to $11 million in retail wine value, applying the common 10:1 formula for retail wine:grape prices. A similar value could be applied to the economic benefits provided to producers in nearby states, which in aggregate have an acreage of premium wine grapes similar that of New York.

Overview