Determination of the efficacy of rhizobacteria obtained from Tokat province on tomato bacterial cancer and wilt disease

This study was performed to determine the effects of rhizobacteria with higher phosphorus dissolving and nitrogen reducing abilities, which obtained from soil rhizospher of tomato plant in tomato production area in Tokat province, on Clavibacter michiganensis subsp. michiganensis [(Smith) Davis et al.] (Cmm) causal agent of tomato bacterial cancer and wilt disease. Twelve rhizobacteria isolates were used in this study. In vitro study, antagonistic effects of the rhizobacteria isolates on Cmm ranged from 13.16 to 88.44%. Based on the result of in vitro studies, rhizobacteria isolates with high effect on Cmm were selected and pot trails and seed applications were carried out with rhizobacteria isolates. In the first pot experiment, Pseudomonas koreensis (R-8) application resulted in 52.78% disease reduction, and P. koreensis+P. thivervalensis (R-9+R-8) combinations also caused 44.56% disease reduction. In the rhizobacteria isolates treatment alone without the pathogen, the rhizobacteria isolates did not have a positive effect on plant growth. In seeds contaminated with Cmm, rhizobacteria isolates suppressed the disease at the rate of 60.97-82.92% in the first trial and 51.51-78.78% in the second trial. It was observed that the rhizobacteria isolates increased only the root length of the seedlings grown from the rhizobacteria isolates coated seeds without the pathogen. As a result of study, rhizobacteria isolates with the highest effect on Cmm in pot experiments and seed applications must carry out on field experiments.