Upland Cotton Lint Yield Response to Several Soil Moisture Depletion Levels

Abstract

Upland cotton lint yield response to several soil moisture depletion levels was measured in 1997 and 1998. In 1997, four Upland cotton varieties including DP 5415, DP 33B, DP 5816, and STV 474 were tested. However because of a nonsignificant variety difference in the 1997 test, the 1998 test was planted to a single variety (DP 33B). In 1997 and 1998, depletion of plant available soil water (PAW) irrigation treatments consisted of 35%, 50%, 65%, and 80%. In 1997, all PAW depletion treatments were significantly different with the 35% PAW treatment resulting in the highest average lint yield of 1880 lbs. lint/acre. The 50%, 65%, and 80% PAW treatments resulted in 1410, 1123, and 248 lbs. lint/acre respectively. There was no significant (P<0.05) difference between varieties within all PAW treatments in 1997. In 1998, all PAW depletion treatments again were significantly different with the 35% PAW treatment resulting in the highest average lint yield of 1658 lbs. lint/acre. The 50%, 65%, and 80% PAW treatments resulted in 1534, 1396, and 641 lbs. lint/acre respectively.