Title: Evaluation of Carica papaya Leaf Extracts for their Efficacy on Control of Bacterial Wilt of Tomato caused by Ralstonia solanacearum
Abstract: Management of bacterial wilt is very difficult as there are no efficient curative chemicals. Carica papaya leaf extract was evaluated their antimicrobial activity against Ralstonia solanacearum. The zone of inhibitions showed against ten R. solanacearum at range of 5.96mm to 15mm of different solvent extracts like aqueous, ethanol, ethyl acetate, hexane, and chloroform. The MIC of methanol at 512 μg/ml, ethanol at 2048 μg/ml, ethyl acetate at 1024 μg/ml, hexane at 1024 μg/ml, chloroform at 1024 μg/ml, aqueous at 2048 μg/ml and streptomycin at <8 μg/ml. The seed treatment with C. papaya leaf extracts increased the seed germination and vigor index (1218.61) when compared to control (1152.69). Under greenhouse conditions plants treatments with C. papaya extracts were increased plant growth and decreased wilt incidence about 42.29-52.14%. In field study the reduction of wilt by C. papaya leaf extracts at 100mg/ml concentration. C. papaya leaf extracts increased the yield by 15.08% (1.3t/ha) and decreased the wilt incidence by 52.14%.