Nursery Diseases of Dipterocarpus macrocarpus and Gmelina arborea in Assam - New Records

Diseases caused by fungi in D. macrocarpus and Gmelina arborea in and around Jorhat, Assam were recorded during 1998-99. Disease incidence and percent infection index or disease severity were recorded and reported. Three fungal diseases in G. arborea namely leaf spot caused by Corynespora cassiicola, leaf blight caused by Sclerotium rolfsii and ischolar_main rot by Fusarium semitectum and in D. macrocarpus, a leaf blight caused by Colletotrichum crassipes were studied. Disease incidence of leaf spot, leaf blight and ischolar_main rot in G. arborea and leaf blight in D. macrocarpus was 95%, 80%and 73% respectively whereas disease severity of leaf spot and leaf blight in G. arborea and leaf blight in D. macrocarpus was 35%, 29.2% and 40.8% respectively. Leaf blight of D. macrocarpus is a new disease from India.