Integrated disease management of Alternaria leaf blight of Sunflower

Sunflower is one of the important oilseed crop grown in India. This crop is affected by several diseases among them Alternaria leaf blight is one of the most important disease causes about 28-80% of yield loss. In this view the cultural studies reveals Carrot medium supported maximum growth of the fungus isolates both on solid as well as on liquid medium and maltose as a carbon source, and Asperagine as a nitrogen source supported the maximum dry mycelial weight. During physiological studies the temperature of 30o C and pH 5 has favoured the growth and development of the fungus. The epidemiological studies showed that maximum temperature and maximum relative humidity (morning) showed positive correlation with disease development. In vitro evaluation of fungicides revealed that, Hexaconazole and Propiconazole at 600 ppm showed 100 per cent inhibition of mycelial growth whereas among the bio pesticides NSKE at 10 per cent, and T. harzianum were induced maximum reduction in colony growth. IDM under field condition revealed that Hexaconazole at 0.1 percent and a combi product Carbendazim+Mancozeb at 0.1 per cent were found to be the most effective in managing the disease.