Effects of leaf:fruit ratios on fruit growth, mineral concentration and quality of mango (Mangifera indica L. cv. Kensington pride).
Simmons S. L., Hofman P. J., Whiley A. W., Hetherington S. E.
Author Affiliation: Department of Agriculture, University of Queensland, St Lucia, Qld 4072, Australia.
Journal of Horticultural Science and Biotechnology 73 : 367-374
Abstract : During 1995-96, thirty 5-year-old uniform Kensington Pride mango trees growing in Queensland, Australia, had selected branches thinned to a single fruit and girdled to provide 30, 60 or 120 leaves/fruit. Control branches were not thinned or girdled, and had on average 36 leaves/fruit. Decreasing the leaf:fruit ratio to 30 resulted in smaller fruits with lower dry matter (generally an indication of fruit maturity), extended the number of days to the eating-soft stage at 22°C (shelf life) by 2 days, increased pulp Ca concentrations, and improved storage performance by reducing external chilling injury. Increasing the leaf:fruit ratio to 60 produced larger fruits and extended shelf life by ~2 days, but had no effect on dry matter or pulp Ca concentrations. A further increase in the leaf:fruit ratio to 120 increased fruit size, dry matter and the severity and incidence of disease, but had no effect on shelf life or pulp Ca concentrations. Girdling had an independent effect on skin colour, with fruits from girdled branches having ~20% less green and 5-12% more red blush on the skin at the eating-soft stage. Girdling also reduced the concentrations of Mg and K in the fruit pulp. Percentage dry matter and Ca concentration in fruit pulp had significant (but weak) negative and positive correlations with fruit shelf life, respectively, suggesting that although both were involved in mango ripening, they were not the major determinants.