Effect of foliar application of manganese and iron on growth characters, yield and fiber properties of some Egyptian cotton cultivars (Gossypium barbadense L.)

Two Field experiments were carried out at the Agricultural Research and Experimental Station, Faculty of Agriculture, Cairo University, Giza, Egypt, during the two growing seasons (2012 and 2013) to study the effect of foliar application of micronutrients (manganese and iron) on growth, yield and fiber quality of some cotton cultivars (Giza 88, Giza 90 and Giza 92). The experiment was laid out in a split plot design in a randomized complete block design arrangement with four replications. Treatments included three cultivars were applied in main plots and five foliar applications of micronutrients (0, 100 and 200 mgl -1 for both manganese, and iron) were applied in sub-plots. Spraying took place twice, at the beginning of the flowering stage and 15 days later. Cotton cultivars were planted during the month of April and harvested in October for both seasons. The results showed that cultivars significantly varied in studied parameters except position of the first sympodial node, fiber strength in both seasons and each of boll weight in the first season and earliness in second season. Foliar application of manganese and iron in both seasons indicated marked improvement and produced significant effect (P ≤ 0.05) on increasing plant height, sympodial branches, bolls number, boll weight, seed cotton yield, lint% and fiber strength. No significant increase were obtained for position of the first sympodial node, fiber length and uniformity index were. The cotton cultivar Giza 90 was found to be the most promising cultivar which responded well to manganese and iron foliar application compared to other cultivars. Also, the data revealed that, the application of manganese and iron at 200 mgl