Optimal leaf nitrogen norms for young and old mango trees (cv. Sensation).
Smith B. L.
Author Affiliation: Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200, South Africa.
Journal of the Southern African Society for Horticultural Sciences 4 : 45-48
Abstract : Trials were conducted in 2 production areas in the Transvaal, namely the Friedenheim Experimental Farm and Hoedspruit on mango cv. Sensation trees. At the start of the experiments, trees were 3 and 10 years old at Friedenheim and Hoedspruit, respectively. Over a period of seven seasons, leaf samples were taken for analysis in Aug., Sep., Oct., Nov. and Dec., when leaves were 4, 5, 6, 7 and 8 months old, respectively. Polynomial regression analysis demonstrated that the norm of young trees (first 4 seasons of production) was 1.25-1.40% N and for mature trees (?10 years old), 1.25-1.50% N. Seven-month-old leaves (Oct./Nov. samples) gave the best correlation between leaf N content and yield. Furthermore, increased leaf N content was associated with a decrease in fruit size.