Field Evaluation of BRRI Boro Rice Varieties for Bacterial Blight Disease

Abstract

Bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases of rice in Bangladesh, causing significant yield losses in susceptible cultivars. The experiment was conducted in a Randomized Complete Block Design (RCBD) maintaining three replications of each treatment. BXO9, the isolate of Xanthomonas oryzae pv. oryzae in Bangladesh was used for inoculation at maximum tillering stage. Variations in the parameters related to BLB indicate the existence of genetic diversity among the tested varieties. The responses to BLB of the variety BR26, BRRI dhan27, BRRI dhan28 and BRRI dhan47 were highly susceptible (HS), while BR3, BR8 and BR15 are moderately resistant (MR). In case of BLB grain sterility (%) in healthy hill ranges from 10.7 to 58.1% and in diseased hill 12.1 to 65.4%. A positive relationship was observed between leaf damage area (LDA) and grain sterility (%) among the varieties. The grain yield (t/ha) in healthy hill ranges from 4.2 to 6.7 t/ha while in diseased hill it ranged from 2.8 to 6.3 t/ha. As the % LDA increased, grain yield (t/ha) decreased compared to healthy hills, and a positive relationship was observed.