Upland cotton lint yield response to varied soil moisture depletion levels

Upland cotton lint yields response to varied soil moisture depletion levels was measured in 1996 and 1997 for four Upland cotton varieties including Delta and Pine 5415, NuCotn 33B, 5816, and Stoneville 474. In 1996, soil moisture depletion treatments consisted of 35%, 50%, 75%, and 90% maximum allowable depletion (MAD) while in 1997, treatments were 35%, 50%, 65%, and 80% MAD. In 1996, the 35% and 50% treatments resulted in the highest statistically similar (p<.05) varietal averaged lint yields of 1374 and 1438 lbs./acre respectively with a corresponding statistically significant lint yield reduction for the 75% and 90% MAD treatments of 713 and 329 lbs. lint/acre respectively. The 1997 treatments were statistically significant with the 35% MAD treatment resulting in the highest varietal average lint yield of 1880 lbs. lint/acre. The 50%, 65%, and 80% MAD treatments resulted in 1410, 1123, and 248 lbs. lint/acre respectively.