Effectiveness of Rhizobacteria to Reduce Rice Blast Disease Intensity

Abstract

Rice blast disease caused by Magnaporthe grisea Barr (anamorf Pyricularia grisea Sacc. synonym Pyricularia oryzae Cav.) is one of important diseases for rice cultivation in Indonesia. Five isolates of rhizobacteria isolated from the rhizospheres of rice in Bali were tested for their effectiveness to reduce the rice blast disease intensity on rice cultivar Ciherang under green house condition. All isolates were formulated in liquid formulas which were respectively contained bacterial suspension of Enterobacter agglomerans Ch2D, Xanthomonas luminescens Ch3D, Enterobacter agglomerans Ch4B, E. agglomerans Gg14D and  Serratia liquefaciens Gh13D.  Results of this study showed that all five formula of rhizobacteria effectively reduced the rice blast intensity on rice cultivar Ciherang. The rice blast intensity on plants treated with  rhizobacteria were varied from 13.96 to 19.44%, while the disease intensity on control was 33.56%. Formula containing bacterial suspension of E. Agglomerans Gg14D resulted in the lowest blast disease intensity and the highest yield per hill. The yield increment resulted from this treatment was 40% when compared to control. This result suggested that E. agglomerans Gg14D is one of promising candidate for bio-control agent to manage rice blast disease. However, the field trial is needed in order to evaluate the stability and effectiveness of the rhizobacteria formula under field condition at several localities.

Keywords: rhizobacteria, rice blast disease, disease intensity