Farm evaluation of Boron and Zinc effects on yield and qualitative parameters of cotton in a calcareous soil

An experiment was carried out in calcareous soil with 0.42 mg.kg-1 available boron (B) and 0.33 mg.kg-1 available zinc (Zn) in research farm of Tehran agricultural and natural resources research and education center to determine the effects of boron and zinc application on quantitative and qualitative characteristics of cotton during the two-years study with using a randomized complete block design with the factorial arrangement. Different levels of boron consumption from boric acid source (0, 5, 10 kg ha-1 application in soil and one as leaf spraying treatment) as boron factor and different levels of zinc consumption from zinc sulfate source (0, 30, 60 kg ha-1) application in soil and one as foliar application were considered as zinc factor. The main effects of boron, the main effects of zinc, and the interaction effects of boron and zinc were significant on yield, yield components, and qualitative properties of cotton fibers. The highest yield, number of bolls per plant, single boll weight, intermediate distance, and plant height and fiber length were obtained from the foliar application. To maximize the yield and improve the quality of the fibers, it is recommended to use zinc and boron foliar spray at a concentration of five per thousand twice during the growing period.