SYMPTOMS On leaves, spots form commonly towards the margins. They are tan to dark brown in colour, often with a darker border. Infection of young leaf flushes may occur when their emergence coincides with rainy weather. These infections often show up as lesions along the margins of the young bronze or pale green leaves, in which case they are semi-circular in shape. In very humid weather new twigs may show a dark affected area from the tip backwards, sometimes with defoliation of the young shoots. © Northern Territory
Government, 2007 Page 2 of 2 When newly formed fruit are affected the anthracnose shows as large, sunken, black lesions and the fruits so affected drop off. Medium to large green immature fruit affected with pre-harvest anthracnose show large lesions which are glossy, black and sunken. With these fruit, splits and oozing often occurs. The most common fruit anthracnose results from latent infections (see above) and is seen as slightly depressed grey-black areas in the skin on ripening fruit. In time the typical pink to orange spore masses (acervuli) form on this tissue.
CONTROL Regular spraying of trees from flowering time onwards with mancozeb (at recommended label rates every 14 days) is useful to reduce the level of infection in the developing fruit. Do not use mancozeb within 14 days of harvest. If anthracnose becomes serious in green immature fruit it would be useful to give a couple of judicious sprays of prochloraz. It is important however not to overuse prochloraz as this may lead to development of resistant anthracnose strains. Copper sprays recommended for the control of mango scab will also control anthracnose with only a one day withholding period. Post-harvest treatments are available for control of anthracnose in mango fruit. Prochloraz is used as a cold nonrecirculating spray. Hot water dips used to control fruit flies will also control anthracnose and stem end rots. Hot benomyl dips will control anthracnose and are useful where stem end rots are a problem.
Controlling Anthracnose in Mango by Tony Rola
Control of Anthracnose must start when you have young flushes (new leaves). Spray the young leaves with 300 grams Copper Oxychloride combined with 2 kilos Muriate of Potash (0-0-60) dissolved in 200 litres of water. Spray at bud break and repeated 3 times at 2 weeks interval.
During fruit production, include fungicide in the spray solution.
After harvest, use hot water dip.