Effect of NAA and Fulvic Acid Spray on Vegetative Growth, Productivity and Fruit Quality of “Taimour” Mango Cultivar

This investigation was conducted on 16-year-old "Taimour" mango trees grown in a private orchard located at Tema district, Sohag Governorate, aiming to study the effect of foliar applications of Fulvic acid at (1000, 2000, and 3000 ppm) and NAA at (15, 30, and 45 ppm) on growth, leaf mineral composition, fruit retention, yield, and fruit quality during the 2019, 2020, and 2021 seasons. This experiment was designed and arranged in a complete randomized block design with three replicates per treatment and one “Taimour” mango tree per each. The selected trees (30) received thrice sprays with NAA before flowering, during full bloom, and after fruit set; meanwhile, Fulvic acid was sprayed thrice (before flowering, after fruit set, and one month later). Enhancements in leaf area, chemical composition, fruit retention percentage, yield, and fruit quality materially accompany single and combined applications with the abovementioned concentrations. A significant decline in the percentages of titratable acidity was observed due to the application of the present treatments. Using Fulvic acid was more effective than NAA for enhancing leaf area and its chemical composition. Moreover, using NAA was superior than using Fulvic acid in terms of improving yield, fruit quality, and fruit retention percentage. Using a combination of both materials was preferable to using them separately. The highest values among all parameters were achieved by spraying "Taimour" mango trees with 3000 ppm Fulvic acid + 45 ppm NAA followed by 2000 ppm Fulvic acid+ 30 ppm NAA in the three experimental seasons compared with control and other treatments. It can be concluded that foliar application of 3000 ppm Fulvic acid+ 45 ppm NAA is useful in improving the vegetative growth and nutritional status of "Taimour" mango trees and produces a high yield with good fruit quality under Sohag Governorate conditions.