Cotton (Gossipium hirsutum L.) Response to Irrigation and Environment in a Short Season Climate

Research was conducted in 2010 and 2011 at the West Tennessee Research and Education Center in Jackson, TN to investigate water deficit and irrigation response in cotton to provide a better understanding of physiological growth changes and yield impact on the crop grown in soils of varying depth to a sandy layer. The deep soil yielded more vegetative mass when compared with the shallower soil. This is also true when applying higher rates of irrigation where plants grew two more nodes of growth and 15.2 centimeters of plant height. Time to cotton maturity was delayed seven days in the deep soil and with the application of irrigation. Canopy density, measured by light interception, was increased in plots grown on the shallow soil profile from 48% to 53% when irrigation was applied. Canopy temperature was reduced when grown in the deep soil profile and with the addition of irrigation. Yield and fiber quality increased with irrigation and when cotton was grown on a deep soil.

Research was also conducted to evaluate cotton variety growth, fiber quality, and yield stability of six varieties during 2010 and 2011 at fifteen on-farm production locations. The variety with the most overall response in growth and plant structure was PHY 375 WRF, with the addition of 3.7 nodes and 21.6 cm of plant height over the plants blooming period. In locations receiving more than 7.6 cm of precipitation during the blooming period, PHY 375 WRF had the highest yield at 1280 kg ha^-1. Regression analysis of yield stability found R² values ranged from 0.89 for PHY 375 WRF and DP 0912 B2RF to 0.74 for PHY 367 WRF. This indicates that 89% of the variation in PHY 375 WRF and DP 0912 B2RF yield can be accounted for by differences in environment, but only 74% of the yield variation of PHY 367 WRF is due to differing environmental factors.