Integrated management of leaf rot disease and insect pests on coconut

Hexaconazole, mancozeb, phorate and methyl parathion in eight different treatment canbinations were evaluated against leaf rot and insect pests of coconut. The palms treated with Mancozeb @ 3 g per palm dissolved in 300 ml water applied twice a year gave maximum reduction in disease indices followed by phorate + hexaconazole and phorate + mancozeb and hexaconazole alone. Superiority of treatment with mancozeb was very clear after each round of observation. At the end of the experiment the average disease index was only 1.0 with 6 out of 8 palms showing no disease symptom. Sanitation followed by application of phorate 20 g mixed with 200 g river sand was better than the application of methyl parathion dust 50 g in controlling leaf rot which indicated that nematodes have a role in the incidence/aggravation/ transmission of fungi between leaflets of the same spindle or to the next spindle. No additional advantage was seen when hexaconazole and mancozeb were applied together or when hexaconazole, mancozeb and phorate were applied together. Phorate - 20 g treated palms were totally free from red weevil, rhinoceros beetle, mealy bugs and other insects compared to methyl parathion dust - 50 g where stray incidences of rhinoceros beetle infestation occurred. Pouring of 3g mancozeb or hexaconazole - 2 ml dissolved in 300mI water after removing rotten portions of the spear leaf followed by application of phorate 20g mixed in 200g fine river sand-to the base of the spindle in April-May and in October-November controlled leaf rot and insect pests on coconut. The coconut water, kernel and oil from mature nuts harvested after 45 days of application of methyl parathion, hexaconazole and mancozeb were free from residues Â