Influence of Potassium Foliar Application on Cotton Yield (Gossypium barbadense L.) under Saline Condition

There is a lack of sufficient information on cotton responses to time and amount of foliar application of potassium (K) under salt stress environment, The objective of this study was to investigate the effects of potassium (as Solupotasse 50% K2O and 18% S) rate and application time on yield and yield components of cotton under saline field condition. A factorial experiment based on randomized complete block design with three replications was conducted in Sabzevar Agriculture and Natural Resources Research center in 2015. Factors were: K rate (0, 1, 2 and 3%) and K foliar application time (at early flowering, at peak boll formation and at early flowering + peak boll formation). Increasing of K concentration to 3% increased plant height, sympodial branch number, boll number, boll weight, seed cotton yield and lint yield. Lint percent was not affected by potassium concentration. The highest boll number and lint yield was obtained when potassium spraying at early flowering stage whereas foliar application at peak boll formation had the highest plant height and boll weight. The maximum seed cotton yield was obtained at K application twice at early flowering + peak boll formation. The results obtained here suggest that 3% K application (as Solupotasse) at early flowering + peak boll formation stage can improve the seed cotton yield grown under salt stress environment.