Six antibiotics named Benzylpenicillin, Ampicillin, Kanamycin, Streptomycin, Chloramphenicol Sinobionic respectively with four concentrations 31.25μg/ml, 62.5ug/ml, 125ug/ml and 500 μg/ml of each antibiotic solution were made and used for the chemical control of BLB disease of rice