Compatibility of Bacillus subtilis with selected antibiotics and fungicides commonly used in field crop

Nine antibiotics and fungicides viz. Streptomycin sulphate, Streptocycline, Chloramphenicol, Bactronol (Bromo - 2 – nitro propane -1,3 diol), Streptomycin sulphate + Copper oxychloride, Copper hydroxide, Validamycin, Copper oxychloride and Kasugamycin + Copper oxychloride were tested against Bacillus subtilis in vitro. The antibiotic sensitivity against thirty isolates was studied by paper disk technique. The Copper oxychloride + Streptomycin sulphate (each @ 100,250,500 ppm) was more effective in the form of zone of inhibition against phylloplane Bacillus subtilis isolate PBs6 and also the streptocycline (each @ 100,250,500 ppm) was more effective against rhizospheric Bacillus subtilis isolate RBs3.