Mode of perpetuation and spread of Alternaria blight of

ABSTRACT: Alternaria alternata causing blight of broad bean iVicia faba L.) remained viable in diseased plant debris through infected leaves and stems upto 11 and 13 months in laboratory and upto 10 and 12 months in soil, respectively. It remained viable in infected seeds upto 15 months in laboratory and upto 13 months in soil. Diseased plant debris, infested soil and infected seeds surved as the primary source of inoculum of the pathogen. Secondary spread of disease occurred through air borne conidia. Key words: Survival, primary and secondary infection, Alternaria alterna/a, broad bean Broad bean (Vicia faba L.) suffers from blight dis-ease caused by Alternaria alternata (Fr.) Keissler. Gupta et al. (1992) reported only its occurrence in Himachal Pradesh. Detailed informations are not available in lit-erature on this ' important disease of broad bean. There-fore, experiments were conducted to find out the mode of survival and spread of the disease in nature. MATERIALS AND METHODS Plant debris (diseased leaves, stems and pod husk