Effects of nitrogen on the skin colour and other quality attributes of ripe 'Kensington Pride' mango (Mangifera indica L.) fruit.
Nguyen H., Hofman P., Holmes R., Bally I., Stubbings B., McConchie R.
Author Affiliation: School of Land Water & Crop Sciences, The University of Sydney, NSW 2006, Australia.
Journal of Horticultural Science and Biotechnology 79 : 204-210
Abstract : Near-ripe fruits of mango cv. Kensington Pride with green skin colour generally return lower wholesale and retail prices. Pre-harvest management, especially nitrogen (N) nutrition, appears to be a major causal factor. To study the extent of the problem in the Burdekin district (dry tropics; the major production area in Queensland, Australia), green mature Kensington Pride fruits were harvested from 10 orchards during 1999/2000 and ripened at 20±0.5°C. Of these orchards, 70% produced fruits with more than 25% of the skin surface area green when ripe. In 2000/2001, the effect of N application on skin colour and other quality attributes was investigated in 3 orchards, 1 with a high green (HG) skin problem and 2 with a low green (LG) skin problem. N was applied at pre-flowering and at panicle emergence at 0, 75, 150, 300 g per tree as soil treatment, or 50 g per tree as foliar N for the HG orchard, and 0, 150, 300, 450 g per tree as soil treatment or 50 g per tree as foliar treatment for the LG orchards. In all orchards, the proportion of green colour on the ripe fruit was significantly (P0.05) higher with soil applications of 150 g N per tree or of higher amount of N. Foliar sprays resulted in a higher proportion of green colour than the highest soil treatment in the HG orchard, but not in the LG orchards. Anthracnose disease severity was significantly (P0.05) higher with 300 g of N per tree or foliar treatment in the HG orchard, compared with no additional N. Thus, N can reduce mango fruit quality by increasing green colour and anthracnose disease in ripe fruits.