SEEDLING DISEASES OF MANGO (Mangifera indica) IN DHAKA AND MANIKGONJ

Abstract

Occurrence and prevalence of diseases of mango was studied in five nurseries located at Dhaka and Manikgonj during January to October, 2007. Altogether six diseases were recorded during the survey. The diseases, in order of prevalence (Incidence and Severity) were Anthracnose (51.14% and 37.39%), Alternaria leaf spot (47.14% and 32.55%), Powdery mildew (33.30% and 26.03%), Red rust (24.05% and 13.05%), Sooty mould (10.50% and ) 0.95%) and Bacterial leaf spot (9.75% and 10.12%). Three" fungi- Colletotrichum gloeosporioides, Alternaria alternaae and Oidium mangiferae and an algaCephaleuros virescencs were identified from Anthracnose, Altermaria leaf spot and Powdery mildew and Red rust infected leaves respectively. However, Sooty mould and Bacterial leaf spot were recorded only on the basis of symptoms observed. The prevalence of the recorded six diseases varied to each other with respect to nursery and its location. Positive correlation was observed between prevalence of Anthracnose and Alternaria leaf spot with temperature and relative humidity. The highest prevalence of Anthracnose and Alternaria leaf spot was observed in October and lowest in January. Negative correlation was observed between prevalence of Red rust and incidence of Powdery mildew. The highest prevalence of Red rust and Powdery mildew was in the month of March, but the disease was observed in October. Report on Alternaria leaf spot first of its kind in mango seedling in the country.