Inadequate moisture during any growth period can reduce corn yield. Nutrient availability, uptake and transport are impaired without sufficient water. Plants weakened by dry conditions are also more susceptible to disease and insects. Severe moisture stress is indicated by leaf wilting that is alleviated only when the plants receive additional water.
Four consecutive days of visible wilting can reduce potential corn yield by 5-10 percent during the vegetative growth stage, or by 40-50 percent during silking and pollination. Moisture stress during this period also can result in a lack of synchronization between pollen shed and silking at pollination, because pollen grains may not remain viable and silking my be delayed.
* Source: Purdue University Corn & Soybean Field Guide 2008 Edition