SURVEY ON RICE BLAST DISEASE INCIDENCE IN MAJOR RICE GROWING AREAS OF BANGLADESH

Abstract

A B S T R A C T Rice blast (Pyricularia oryzae Cavara) is one of the most devastating diseases that cause severe yield losses every year in Bangladesh. Eight rice-growing districts of Bangladesh, namely Dinajpur, Rangpur, Bogura, Natore, Meherpur, Rajbari, Mymensingh, and Jashore, were surveyed to estimate the incidence and severity of leaf and neck blast diseases of rice at vegetative and reproductive stages. The highest leaf and neck blast incidence of 28 and 11% was observed in Dinajpur, whereas it was the lowest in Rajbari and Jashore. The leaf blast severity ranged from 28% in Dinajpur to 2% in Rajbari and Jashore. The highest neck blast severity was recorded in Dinajpur, whereas the lowest was observed at Rajbari and Jashore. The study revealed that rice blast disease (leaf and neck blast diseases) is more prevalent in the northern regions of Bangladesh acts as a hot spot for the disease having the ideal predisposing conditions compared to southern regions.