Int.J.Curr.Microbiol.App.Sci (2020) 9(6): 3570-3575 3570 Original Research Article https://doi.org/10.20546/ijcmas.2020.906.420 Bioefficacy of Chemicals against Bacterial Leaf Blight Disease of Rice A. Khandual 1,2 , M. K. Mishra 1 , H. Swain 2 , S. Mohanty 1,2 , P. C. Rath 3 and A. K. Mukherjee 2* 1 Department of Plant Pathology, OUAT, Bhubaneswar, India 2 Molecular Plant Pathology Laboratory, Crop Protection Division, ICAR-NRRI, Cuttack, India 3 Crop Protection Division, ICAR-NRRI, Cuttack, India *Corresponding author ABSTRACT Introduction Rice, the golden cereal, is an important part of daily human food and provides carbohydrates, proteins, minerals and vitamins (Pradhan et al., 2019). With the global population expanding at a rapid rate, it warrants a solution to food scarcity and hunger. To provide food for the billions, the productivity of rice needs to be increased. But yield losses tend to rise with swelling pest population which is the consequence of changing climate and agroecological systems. A number of diseases pose threat to the rice industry and bacterial leaf blight (BLB) is a major one which can hamper more than 70% yield (Reddy et al., 1979). BLB is caused by Xanthomonas oryzae pv. oryzae (Xoo), which enters the plant system via hydathodes (Nino International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 6 (2020) Journal homepage: http://www.ijcmas.com Bacterial leaf blight of rice, caused by Xanthomonas oryzae pv. oryzae is not only a problem in India but also worldwide. Management using chemicals is undoubtedly quick in action, restricting the severity and spread of the disease. Both in vitro and in vivo studies were conducted to investigate the inhibitory potential of different chemicals against the bacterial pathogen. Out of eight chemicals comprising both antibiotics and fungicides, Streptomycin sulphate 90% + Tetracycline hydrochloride 10% exhibited highest inhibitory effect in lowest concentration of 100 ppm followed by 2-bromo-2-nitropropane 1,3-diol (15.5%). Streptomycin sulphate 90% + Tetracycline hydrochloride 10% @ 100 ppm proved best in controlling BLB in pot condition with 42.2% disease reduction and 121 % yield increase over control. Keywords Bacterial leaf blight, Rice, Chemicals Accepted: 26 May 2020 Available Online: 10 June 2020 Article Info