What Happens Within The Corn Plant When Drought Occurs?
By Joe Lauer, Corn Agronomist, University of Wisconsin-Extension August 20,2003 Many areas of Wisconsin have not had rain for three to four weeks, and corn is showing signs of stress early in the morning (stress-day). Many are concerned about how this will affect corn yields. To begin talking about water influences on corn growth and development and yield we must begin with the concept of evapotranspiration. Evapotranspiration is both the water lost from the soil surface through evaporation and the water used by a plant during transpiration. Soil evaporation is the major loss of water from the soil during early stages of growth. As corn leaf area increases, transpiration gradually becomes the major pathway through which water moves from the soil through the plant to the atmosphere. Yield is reduced when evapotranspiration demand exceeds water supply from the soil at any time during the corn life cycle. Nutrient availability, uptake and transport are impaired without sufficient water. P
