Efficacy of Plant Extracts Against Bacterial Blight (Xanthomonas oryzae pv. oryzae) of Rice

Leaf extracts of 14 plants were evaluated against Xanthomonas oryzae pv. oryzae (Xoo) by paper disc diffusion and food poison methods. Maximum inhibition of Xoo was observed at 20% (15.6 rom) and 15% (12.2 rom) concentrations of Datura metel followed by Azadirachta indica at 20% (8.6 rom) and 15% (6.8 rom) concentrations. Lesion length caused by virulent isolate of Xoo (Kaul isolate) was reduced significantly from 9.3 cm (at 14 days after inoculation and 15.5 em (at 21 DAI) in the untreated control to 3.1 em (at 14 DAI) and 4.3 em (at 21 DAI) on treatment with 15% of Datura metel.