The recovery of physiological processes following irrigation of water-stressed extra long-staple cotton

Abstract

In the southwestern United States, rising costs and limited availability of water have lead to irrigation scheduling based on plant stress indicators in an effort to conserve water. This research was conducted to better define the recovery rates of transpiration, stomatal resistance, and leaf water potential in field grown extra long staple cotton (Gossypium barbadense cv. Pima S-6) following varied durations of water stress. Three water stress treatments were maintained by scheduling irrigations at different Crop Water Stress Index (CWSI) values. Plants irrigated at 0.19 and 0.68 CWSI units needed 72 hours for plant water potential to recover, while plants irrigated at 0.41 CWSI units needed only 24 hours. Water stress had a smaller effect on the recoveries of stomatal resistance and transpiration. Stomatal resistance recovered within 24 hours for all plants regardless of water treatment. Transpiration recovered within 24 hours for plants irrigated at 0.19 CWSI units, and within 48 hours for plants irrigated at 0.41 and 0.68 CWSI units.