Foliar boron application affects lint and seed yield and improves seed quality of cotton grown on calcareous soils

Cotton (Gossypium hirsutum L.) is one of the most important fiber crops worldwide because of the good fiber quality, high yield, and high adaptability. Cotton has high requirements for B and many times B is applied to correct B deficiency. Despite the fact that B is important for cotton the effect of foliar applications on seed yield and seed quality was not adequately determined and especially when cotton is grown on calcareous soils. A field study was conducted to determine if foliar B application during anthesis increases seed set, lint yield, seed yield, yield components and improves seed quality of cotton grown on calcareous soils. Boron solutions were applied at four rates (0, 400, 800 and 1,200 mg l⁻¹ of B) to field plots exhibiting no vegetative symptoms of B deficiency. Foliar B application increased the number of bolls per plant, the number of bolls per square meter, the mean boll weight, the lint and the seed yield. Cotton yield was increased by an average of 40% over the two locations with B application compared with the control. However, there was no significant difference between the three rates of B. The number of bolls per plant increased by an average of 29% and the number of bolls per square meter increased by an average of 29% with B application in both locations compared with the control treatment. Also foliar application of B improved seed germination by an average of 17% and increased seed vigor determined as accelerated aging (AA) by an average of 25% compared with the control treatment in both locations. The results obtained here suggest that foliar B application can improve the lint and seed yield and seed quality of cotton grown on calcareous soils.