Studies on the effect of autumn fungal diseases of mulberry and their impact on cocoon production in Doon valley

Abstract

Mulberry is the sole food plant of Silkworm (Bombyx mori L.). The success of Silkworm depends on the Mulberry leaf quality and climate. Damp and humid condition of the Doon valley promotes the development of pathogenic fungi. A survey on the incidence and severity of foliar fungal diseases of Mulberry during autumn period was conducted in the Doon valley at RSRS, Sahaspur, Dehra Dun. Incidences of major diseases viz., powdery mildew (Phyllactinia corylea), leaf spot (Cercospora moricola), leaf rust (Cerotelium fici), and leaf blight (Fusarium solani) were recorded during autumn season (September to November). Leaf spot disease was found mainly (PDI, 8.7 and DI%, 32.0%) in October, 2003 during autumn season at RSRS, Sahaspur, Dehra Dun and followed by September (PDI, 7.5 and DI%, 19.7%). Leaf rust was also observed during September as minor disease (PDI, 1.6 and DI%, 5.3%), whereas the same disease was found as major disease in other traditional areas like Karnataka and West Bengal. The severity of powdery mildew disease was observed in the month of November (PDI, 34.9 and DI%, 79.9%). Disease severity and weather parameters have also been discussed.