Irrigated Sweet Corn Crop Production Functions and Efficient Water Use1

The yield of sweet corn (Zea mays L.) and seasonal evapotranspiration as affected by different amounts of irrigation water was studied in a field plot experiment during 1991 and 1992 in the Jordan Valley. Four different amounts of irrigation water were imposed with trickle irrigation on a clay soil. The different sweet corn components differed in their response to seasonal evapotranspiration. Sweet corn yields of total fresh and total oven dry matter at W3 (W3 = E_o) and W4 (W4 =1.5 EJ were significantly higher than yields at lesser water amounts (W1 = 0.25 E_o and W2 = 0.5 EJ, while good husked fresh ear yield at W4 was significantly higher than yield at W1, W2, and W3. Seasonal evapotranspiration increased in a decreasing rate as total water applied increased. Increasing total water applied more than 400 mm resulted in a negligible increase in sweet corn seasonal evapotranspiration. Crop productivity and water use index (defined as the change in crop yield per unit change in seasonal evapotranspiration) were the highest, when optimal water levels were used.