Recent advances in the management of fungal pathogens of fruit crops.
Arun Arya
Author Affiliation: Department of Botany, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, India.
: 3-13
Abstract : Fruits constitute a rich source of sugars, vitamins, minerals and medicinally important compounds like flavonoids, which prevent cancer and cardiovascular diseases. These are eaten as a dessert or processed into jams, jellies, ice creams and drinks; grapes are dried to make raisins. The science of protecting fruit crops began with the discovery of Bordeaux mixture by P.A. Millardet in France. But still we have yet to find many new techniques and fungicide formulations to control diseases; such as bunch rot of grapes (Botrytis cinerea), apple scab (Venturia inaequalis), wilt of guava (Fusarium solani), Panama wilt of banana (F. cubense), mango malformation (F. moniliforme), blue mould of citrus (Penicillium citrinum) and anthracnose of papaya (Colletotrichum papayae), etc. Losses from postharvest fruit diseases range from 1 to 20% in the USA and from 10 to 40% in India. The pathogens have developed resistance against various fungicides and the postharvest phase is minimized. Alternative strategies like the use of biocontrol methods and the application of botanicals have been tried. A large number of plants are screened for the presence of effective secondary metabolites. Integrated pest management, using improved cultural practices (pruning methods to control Botrytis bunch rot in grapes), the use of solarization (in strawberries), the application of growth hormone (NAA in the case of mango malformation), along with minimum dosage of fungicides, are recommended to control various fruit diseases. The world fruit market is expanding; we are more concerned about human nutrition now, but at the same time serious enough to protect the environment from pollution. The economics of a success story will have to revolve around the use of various cutting-edge technologies and, at the same time, the use of simpler and more effective methods acceptable to fruit growers. Biotechnologists have tried to enhance the activity of biocontrol agents; at the same time, efforts are being made for genetic transformation involving molecular breeding. This technology involves intimate knowledge of the gene, regulatory components and gene functional environment (i.e. the domain where the gene is located). Once an understanding of the molecular basis of genes involved in resistance has been achieved, we will be able to isolate the alleles of those genes and their inclusion will lead to transformed, diseasefree plants.