Bacteriological control of fire blight caused by Erwinia amylovora [(Burr.) Winslow et al.)] using bacteriopage and beneficial microorganisms

Fire blight is the most destructive bacterial disease of stone fruit trees. In this study, the pathogen isolated from different provinces and districts was identified by classical and molecular methods and its biological control was studied. In this context, epiphytic bacteria and yeasts were isolated and a total of 503 candidate antagonist isolates were obtained. The effects of the isolates against the disease were investigated under in vitro, semi-in vivo and in vivo conditions. Two different greenhouse trials were conducted with 11 successful antagonist bacterial isolates under in vivo conditions. Two antagonists (AKMrArC-1 and BIBoEY-3) were found to be highly successful and prevented the disease by 91,7-90,0% and 85,0-88,3%, respectively. These antagonists were identified as Pseudomonas graminis by MALDI-TOF MS at species level. These isolates were more effective than 80% Fosetyl-Al chemical, Bacillus subtilis QST 713 biological preparation and streptomycin sulphate antibiotic in suppressing the disease. For bacteriophage isolation, surveys were carried out in the gardens where the disease was observed and 59 bacteriophages were isolated. The effects of phages against the disease were investigated under semi-in vivo and in vivo conditions. According to the results of in vivo experiments conducted under greenhouse conditions, the disease inhibition rates of bacteriophage cocktails varied between 41.67% and 68.33% in the first greenhouse experiment and between 51.67% and 68.33% in the second greenhouse experiment. In both greenhouse experiments, cocktail phage treatments were more effective than Bacillus subtilis QST 713 biological preparation and streptomycin sulphate antibiotic. This PhD study is the first study in our country to determine the possibilities of using bacteriophages in the biological control of fire blight disease.