Field survey method for determining mango leaf norms.
McKenzie C. B.
Author Affiliation: Merensky Technological Services, PO Box 14, Duivelskloof 0835, South Africa.
Yearbook - South African Mango Growers' Association 15 : 48-52
Abstract : A survey method for optimum leaf norm determination was tested on high-yielding mango trees of varying fruit quality. Sixty Sensation and 20 Kent trees were selected from 7 growers covering a wide range of foliar N concentrations. The yield and quality of fruits from these trees were related to leaf nutrient concentrations. High N concentrations were related to poor background skin yellow colour development and high jelly seed incidence. Ca and K concentrations, despite dropping to well below half the accepted norms, had no adverse effects on fruit quality. Due to high variability, yield relationships were far more difficult to determine. However, there was no clear reduction in yield at nutrient concentrations well below the accepted norms. The indications are that the survey method is an economic and rapid way of determining optimum leaf norms in mango.