Evaluation of spp . , and Trichoderma Pseudomonas fluorescence for biological control of Ralstonia wilt of tomato Bacillus subtilis

is the major bacterial disease in tomato, Background: Ralstonia solanacearum which invades the roots of diverse plant hosts and colonizes xylem vessels causing wilt, especially in tropical, subtropical and warm-temperate regions. R. produces several toxins helping it to invade the plant’s natural solanacearum defense mechanism. Native isolates of Trichoderma spp., Pseudomonas and can be used as biocontrol agents to control fluorescence Bacillus subtilis the bacterial wilt and combined application of these beneficial microbes can give better results. Bacterial wilt infection in the field was identified by field experts and Methods: the infected plant part was used to isolate in CPG Ralstonia solanacearum media and was positively identified. Subsequently, the efficacy of the biocontrol agents was tested and documented using agar well diffusion technique and digital microscopy. 2ml of the microbial concentrate (10 cfu/ml) was mixed in one liter of water and was applied in the plant root at the rate of 100 ml per plant as a treatment method. It was observed that the isolated spp. AA2 and Results: Trichoderma PFS were most potent in inhibiting the growth of Pseudomonas fluorescence R. showing ZOI 20.67 mm and 22.33 mm, respectively. Digital solanacearum, microscopy showed distinct inhibitory effect on the growth and survival of R. The results from the field data indicated that spp. solanacearum. Trichoderma and alone were able to prevent 92% and 96% of Pseudomonas fluorescence the infection and combination of both were more effective, preventing 97% of infection. Chemical control methods prevented 94% of infection. Results showed the bio-efficacy of the native isolates. The Conclusions: various level of antagonistic effect against shown by all 13 R. solanacearum isolates, including the results shown by native isolates in the field, manifested the promising potential of the biocontrol agents, like and Trichoderma against controlling the bacterial wilt infection. Pseudomonas 1 2