Biological Control of Blossom Blight and Brown Rot Caused by Monilinia laxa by Using a Bacillus subtilis Strain TV-6F

Monilinia laxa (Aderh & Ruhl.) is the most important factor of fruit rot disease, especially in peaches, infecting flowers, stems, shoots and fruits of the host. It causes brown discoloration on infected leaves, flowers and flower stalks, causing drying and cankers on shoots. In disease control, chemical fungicides typically provide adequate control of most foliar fungal pathogens. However, the development of fungicide resistance, pesticide residues related to the environment and human health, and the withdrawal of registration of some commonly used fungicides have raised concerns. For this reason, the use of biocontrol agents, which are accepted as a safer method compared to chemical fungicides and with effective results, has been encouraged. A total of seven potential bioactive bacteria were used in in vitro tests in the studies. Three different concentrations (1000, 1250 and 1500 ml per 100 L−1 water) of this TV-6F bioactive bacterial formulation (107 cfu mL−1), which was determined to be Bacillus subtilis according to the sequence analysis results, were used. It was determined that the 1500 ml L−1 dose of the tested TV-6F bioagent bacterial strain was 84.06% more effective in controlling Monilinia in peach flowers than the control group without application and was comparatively successful in disease control.