The wine industry contributes $4.3 billion to the New York economy every year, and powdery mildew is the most serious disease facing producers. To the extent that our research has increased the accuracy of advisory systems for disease management, it has lessened the risk of crop loss. Forecasting systems are only as good as their biological underpinnings. Our research will supplant vague associations that sometime work and sometimes fail with scientifically sound and quantifiable rules based upon direct relationships between the grapevine and its environment.
impact statement issue
The issue we faced was that infection was occurring, but the disease was failing to progress beyond an incipient stage. This made it a vulnerable time to manage, if we could understand the process that was causing the suppression.
impact statement response
We have experimentally determined the conditions that lead to low-temperature suppression of grape powdery mildew and are incorporating this information into disease warning systems.
impact statement summary
Powdery mildew is one of the world's most destructive diseases of grapevines. We know that infection of grapevines occurs as soon as they begin to grow in spring, but epidemics seem to stall for about six weeks and go nowhere fast. We've found that it's our cold nights that are suppressing the disease. Two modes of action are suggested. First, cold nights stimulate a temporary defense response in the youngest, and ordinarily most-susceptible leaves. Second, cold causes direct damage to the mildew colonies. In effect, our cold nights are playing a game of environmental "Whack-a Mole" with the developing mildew colonies.