Effect of Magnesium and Urea Foliar Application on Yield, Quantitative Characteristics and Improvement of Leaf Red Color in Two Cotton Cultivars

Due to the effect of nitrogen and magnesium on leaf red color reduction and their effect on yield and quantitative characteristics of cotton, this study was conducted as factorial in randomized complete block design with three replications. The first factor consisted of two cotton cultivars (Sai, Bcra and Bakhtegan) and the second factor consisted of 10 levels of fertilizer treatment (1- phosphorus and potassium fertilizers based on soil test, 2- nitrogen, phosphorus and potassium fertilizers based soil test, 3- nitrogen, phosphorus and potassium fertilizers based on soil test with foliar application0.5% magnesium sulfate, 4- nitrogen, phosphorus and potassium fertilizers with foliar application 1% magnesium sulfate, 5- nitrogen, phosphorus and potassium fertilizers with foliar application with 1% urea fertilizer, 6- nitrogen, phosphorus and potassium fertilizers with foliar application 2% urea fertilizer, 7- nitrogen, phosphorus and potassium fertilizers with foliar application 0.5% magnesium sulfate and 1% urea, 8- nitrogen, phosphorus and potassium with foliar application 0.5% magnesium sulfate and 2% urea, 9- nitrogen, phosphorus and potassium fertilizer with foliar application 1% magnesium sulfate and urea, 10- nitrogen, phosphorus and potassium fertilizers with foliar application 1% magnesium sulfate and 2% urea. Statistical analysis of data showed that the effect of cultivar on boll weight, number of reproductive branches, number of fertile bolls, and red color of leaf was significant. The results also showed that the effect of fertilizer treatments on yield, boll weight, number of infertile bolls, and cotton plant height were significant at 1% level and leaf reddening was significant at 5% level. The results of the mean comparison showed that the highest yield was observed in nitrogen fertilizer treatment with 0.5% magnesium sulfate and 1% urea and the lowest yield in NP treatments in both Sai Acra and Bakhtegan cultivars.