ISHS Acta Horticulturae 291: III International Mango Symposium
STEM END ROT OF MANGO IN AUSTRALIA: CAUSES AND CONTROL |
| Authors: | G.I. Johnson, A.W. Cooke, A.J. Mead, I.A. Wells |
| Abstract:
Since 1986, over 6,000 mangoes cv. Kensington Pride from twelve locations in Queensland and one in the Northern Territory have been monitored for stem end rot development. Dothiorella dominicana has been the predominant cause of stem end rot at all sites. Lasiodiplodia theobromae (Syn. Botryodiplodia theobromae), Phomopsis manqiferae and other fungi (Dothiorella manqiferae, Cytosphaeria manqiferae and other Dothiorella spp.) caused stem end rot much less frequently (<10% affected fruit), although a higher incidence of L. theobromae or P. manqiferae (30–40% of affected fruit) occurred at a few sites. At six of the Queensland sites, incidence of stem end rot on fruit from tagged trees has been monitored within and between seasons. Incidence was higher in older trees and in unsprayed trees. Possible sources of inoculum were assessed. D. dominicana was the main cause of twig dieback. The teleomorph of D. dominicana (Botryosphaeria sp.) was collected from dead twigs of mango found in leaf litter. Concurrent with studies on disease etiology and the seasonal severity of stem end rot, the effects of pre-and post-harvest fungicide treatments have also been examined. Pre-harvest sprays with copper oxychloride, iprodione or propiconizole reduced the incidence of stem end lesions. Post harvest treatment in hot benomyl provided good control of stem end rot caused by both D. dominicana and L. theobromae during storage at 20°C for 14 days. Hot benomyl followed by prochloraz provided effective control of stem end rot caused by D. dominicana and of alternaria rot (Alternaria alternata) during longer storage in a controlled atmosphere (3 weeks +) at 13°C. As trees in Australian plantations become older, the losses from stem end rot will increase. An integrated control program involving pre-and post-harvest control measures will be required to minimise losses. | |
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