Markus Keller says that regulated deficit irrigation can be beneficial for most red wine grape varieties, but timing of stress is important. During a field day last summer, he showed the drip system installed in a new Washington State University wine grape planting. In the wild, Vinifera grapes can grow under very dry conditions with little water. But to produce high quality fruit for premium wine, when grapes receive water is as critical as the amount, says Washington State University’s Dr. Markus Keller. Wine grapes are quite drought tolerant and can get by with less than 20 inches of water […]