THE EFFECT OF WATER STRESS ON VINEYARDS AND WINE QUALITY

In the humid climates of the Eastern US, rainfall is erratic. The occurrence, duration and severity of drought stresses are not easy to predict. Do we have significant problems due to drought (significant enough to change cultural practices or invest in irrigation)? We know the answer depends on factors such as how dry the seasons are, how much water our vineyard soil holds, how much the vines need, and loss to competing plants. Since we cannot predict the weather, we must take a risk assessment approach, and then evaluate methods to reduce risks we find. To do that we need to understand the factors that either increase or decrease our risks of significant loss from drought stress. Similar to our personal economics, risk of water stress is related to the balance of supply to demand, not either alone. The lowest risk of loss due to drought occurs when the water supply is high and the demand is low. Conversely, when the supply is low and the demand is high, the risk is high and the potential benefits of irrigation are greatest. Besides seasonal rainfall several factors are involved in the total risk, and they should be evaluated separately since some cannot be easily changed while others can. To access the full text of this article, follow the link on the right.