This study was conducted to evaluate the effect of kinetin at 25, 50 and 75ppm and tryptophan at 50, 100 and 150ppm as a foliar spray on vegetative growth, histological features and leaf chemical composition of newly planted (one year old) mango cv. Keitt. All tested concentrations of kinetin and tryptophan succeeded in improving vegetative growth i.e. plant height, stem diameter, branch length, number of branches/plant, number of growth cycles, number of leaves/branch, leaf fresh and dry weight , and leaf area and reduced vegetative malformation percentage in both seasons as compared with control. However, the highest values of stem diameter, number of branches/plant, number of growth cycles, number of leaves/branch, leaf fresh and dry weights and leaf area were scored by the high level of kinetin (75ppm). While, the tallest plant and longest branch were scored by 150ppm tryptophan-sprayed plants in both seasons. Moreover, the lowest vegetative malformation percentage was registered by the high level of tryptophan (150ppm). Furthermore, all tested treatments of kinetin and tryptophan enhanced most of the studied leaf anatomical features i.e., midrib thickness, length and width of vascular bundle, phloem and xylem tissues and number of xylem vessels in vascular bundle as well as the leaf blade thickness. The highest leaf N, P, K and total carbohydrates percentage were detected by the high level of kinetin, whereas the highest value of total indols as well as the lowest value of total phenols content were registered by 150ppm tryptophan-sprayed plants in both seasons. |
