In vitro Screening of New Fungicide Molecules against Alternaria sp. Isolated from Tomato

Early blight disease caused by Alternaria spp. is one of the major limiting factors in tomato-growing areas of the country, causing considerable yield loss. Early blight can be effectively managed by cultural practices, chemical fungicides, and through the use of resistant genotypes. Cultural practice alone are not sufficient for the control of early blight, hence several fungicides have been developed and tried for the management of early blight. In the present study, in order to develop effective management practices against the early blight of tomato, a total of 22 fungicides comprising six systemic, six contact and ten combi products were tested for their fungitoxicity against Alternaria sp. under in vitro by following the poisoned food technique. All the fungicides significantly reduced the radial mycelial growth of Alternaria spp. Based on the maximum inhibition at the lowest concentration, the six fungicides i.e. Hexaconazole 5% EC (50.00), Propiconazole 25 % EC (65.00), Tebuconazole 25.9% EC(53.03),Mancozeb 75 % WP (54.44), Propineb 70 % WP (50.00), Copper oxychloride 50 % WP(63.15), Tricyclazole 45% W G + Hexaconazole 10 % WG(93.17), Fluxapyroxad 250 g/L + Pyraclostrobin 250 g/L SC (92.08)and Zineb 68% + Hexaconazole 4% WP(86.01)were recorded the best against Alternaria sp. compared to control.