Effect of some physical and chemical factors on germination of conidia of Alternaria alternata (Fries) Keissler causing fruit rot of apple was investigated. The germination was maximum at $30^{circ}C$, 100 per cent RH and at 5.5 pH Syllit, amongst the 11 fungicides and Planofix, amongst the 5 growth regulators caused maximum inhibition of conidial germination.