The potential of disease predictions: tools to measure the efficacy of orchard and packhouse management practices, and to predict quality of fruit on the export market.
Swart S. H., Kalinowski J.
Author Affiliation: Du Roi QMS & Pathological Services, P. O. Box 66, Letsitele 0885, South Africa.
: 116-121
Abstract : The value of measuring disease levels at critical control periods during the production of 'Tommy Atkins' and 'Kent' mangoes in three major production areas of South Africa, namely Letsitele Valley, Constantia and Hoedspruit, were investigated during the 1999/2000 season. Soft brown rot (Nattrassia mangiferae), stem-end rot (Lasiodiplodia-Dothiorella complex) and anthracnose (Colletotrichum gloeosporioides [Glomerella cingulata]) were studied. Results showed that each measured parameter has its own value for making timely adjustments to disease control strategies aimed at specific problems during the growing season. Climatic conditions and orchard practices applied during the normal course of mango production can affect disease severity between subsequent measuring points, and therefore influence the relationships between these points of evaluation. The relationships between inoculum potential and early disease potential and between orchard decay potential and packhouse decay potential are valuable management tools in preharvest management strategies. Orchard decay potential and packhouse decay potential can also be used to predict fruit quality and to ensure that only the best quality fruits are available in export markets. Packhouse decay potential is also useful to establish the efficacy of postharvest and packhouse practices to address problems within two weeks after fruits have been packed and not only when reports come from the export markets.