Impact of abiotic and nutritional factors on the growth of Alternaria solani causing early blight of potato

An experiment was conducted to study the impact ofabiotic and nutritional factors on the growth of Alternaria solani causing early blight of potato at College of Horticulture, Bidar during 2013–14. Opt imum pH for the growth of A. solani was in the range of 6.5 to 7.0. The fungus thrived well at a temperature of 25°C followed by 30°C. Light had profound effect on growth and sporulation of fungi. The maximum growth of 89.8 mm was noticed when exposed to 12 h dark 12 h light followed by 24 h light 24 h dark. Among various carbon compounds tested in the present study, glucose supported maximum growth of A. solani, where as minimum growth was observed in lactic acid. Among nitrogen sources tested threonine and asparagine supported maximum growth of A. solani. These two amino acids may be involved in vegetative and reproductive growth.