Recurring incidence of sooty mould of mango in Karachi and its control.
Maria Hamid, Jalaluddin M.
Author Affiliation: Department of Botany, University of Karachi, Karachi-75270, Pakistan.
International Journal of Biology and Biotechnology 3 : 561-565
Abstract : The sooty mould fungi present in sooty mass on the upper leaves of mango (Mangifera indica) (from Karachi, Pakistan) were studied and identified. The sooty mould disease involved 18 fungi, including species of Aspergillus, Alternaria, Botryodiplodia, Capnodium, Cladosporium, Curvularia, Fusarium and Helminthosporium spp. Altogether, 18 species of sooty mould fungi belonging to 8 genera were found. The mealy bugs appeared first as white specks on the under surface of mango leaves and a causal connection between sooty moulds and mealy bugs on mango leaves have been explained. The blackening of the mango foliage was found due to the growth of sooty mould fungi. Its presence in the form of black spots and blemish on mango fruits reduce the value of mango fruits. Spraying of fungicide (sulfur and dithane M-45 [mancozeb]) and insecticide (malathion, diazinon and coal tar at 1 kg/tree) separately on mango foliage reduced the incidence and spraying a mixture of the two (insecticide + fungicide: diazinon + dithane M-45 and mineral oil 1% + starch) further decreased the level of incidence when applied at an early stage of the disease incidence. Repeated application of liquefied coal tar around the base of the stem was found cheaper and more effective than mineral oil mixed with starch for preventing the female mealy bugs from crawling and climbing on mango trees before flowering and formation of mango fruits.