Effect of time and amount of seaweed extract on yield and yield components of cotton in saline conditions

In order to investigate the effect of foliar application of seaweed extract on yield and yield components of Cotton under salinity stress, a factorial experiment in a randomized complete block design with three replications was conducted in Sabzevar Agricultural and Natural Resources Research Center in 2017. The experimental factors included application rate of seaweed extract at four levels of 0, 2, 4, and 6 ‰ and foliar application time at two levels at the vegetative and vegetative+flowering stage. The results showed that the time of seaweed extract application had no effect on the number of sympodial branches, the number of bolls, boll weight and grain yield, while foliar application of seaweed extract at vegetative + flowering increased the final height, lint percent, cotton seed yield and fiber yield. Foliar application at a concentration of 6 ‰ of seaweed extracts increased 31.19% in height, 32.19% in sympodial branches, 41.44 in boll, 23.25% in boll weight, 41.43% seed cotton yield, 61.43%, seed yield, 29.66%, fiber yield and 42.34% lint percent, In general, the results of this experiment showed that two times foliar application of seaweed extract at level 6 per thousand in vegetative and flowering stages were recommended for producing maximum yield and yield components of cotton under salt stress conditions.