Effect of spraying chelated and nano microelements on growth and nutritional status of Zebda mango trees

This study was performed during 2019, 2020 and 2021 seasons to examine the effect of nano versus chelated micronutrients (Fe, Zn, and Mn) on some growth aspects and the nutritional status of Zebda mango trees grown under Aswan region conditions. Zebda mango trees were sprayed three times during the season with nano micronutrients (Fe, Zn, and Mn) at 2.5, 5, 10 or 20 ppm or via chelated micronutrients at 25, 50 or 100 ppm. All growth aspects, namely shoot length and thickness, number of leaves per shoot, and leaf area, as well as leaf pigments and nutrients content, namely chlorophylls a, b, total chlorophylls, and total carotenoids, N, P, K, Mg, Fe, Zn, and Mn, were remarkably enhanced in response to spraying the trees with micronutrients (Fe, Zn, and Mn) in the chelated form at 25 to 100 ppm or via nano form at 2.5 to 20 ppm over the control treatment. Nano Fe, Zn and Mn micronutrients was superior than application of these nutrients in their normal form (chelated form) in improving the growth and nutritional status of Zebda mango trees. The maximum values were recorded when nano micronutrients (Fe, Zn, and Mn) were applied at 20 ppm.