Reproductive Compensation of Cotton after Salt Stress Relief at Different Growth Stages

Differential salt sensitivity during growth stages and reproductive compensation of plants after salt stress relief are important factors for adopting appropriate irrigation strategies with saline waters. Consequently, recovery of cotton after exposure to different levels of salt stress was evaluated. An outdoor, sand culture experiment was conducted with cotton. Water salinities were 2, 10 and 20 dS m(-1), and the growth phases were vegetative (G1), reproductive (G2) and boll development (G3). G1 and G3 were the least and the most salt tolerant phases, respectively. The significant yield reduction in all of the saline water treatments as compared to control was mainly due to the reduction in number of bolls per plants. In general, cotton plants were capable of producing seed cotton under salt stress, as well as, after salt stress relief. However, as the salt stress severity increased the ability of cotton to compensate yield loss decreased. Irrigation of cotton at G1 stage with either moderate (10 dS m(-1)) or high (20 dS m(-1)) salinity waters should be avoided. Moderate saline water could be applied either at G2 or G3 stage. High salinity water can be used for irrigation only at G3 stage to produce acceptable cotton seed yield.