The investigation of biological control possibility of tomato early blight Alternaria solani (Ell. & Mart.) L.R. Jones and Gout

Early blight Alternaria solani (Ell. & Mart.) L.R. Jones and Grout.causing important yield losses in tomato field is a difficult to be controlled by rotation as it can survive for a long time in the soil and it has wide host environment. Concerns about the adverse effects of environment, human and animal health, the endurance and the problem of residuals on chemical used in the controling against plant diseases have prompted scientists to seek new, more economical and effective ways of alternative methods to chemical control. One approach that comes to mind in this context is the use of microbial bioassays to control diseases and pests. For this reason, it is very vital to decide the biological controling agents against the pathogen and to offer effective uses. This study tries to determine of fungus and bacterial isolates that can be as biological control agents against. This study used the data in the previous studies; a total of 13 bioassay bacteria identified according to the Microbial Identification System (MIS), isolated from underground or overland parts of wild and cultivated plants, and also tested for effectiveness in previously conducted studies on different plant pathogens and detected in the molecular system a total of 2 isolates of Trichoderma harzianum were used. The effectiveness of these bacteria and fungi against pathogens has been tested in vitro conditions and the effectiveness of 6 most effective bacteria and 1 fungus is determined in vivo conditions. For this purpose, 3 potted plants were constructed with 3 repetitions, 3 pots were isolated only as pathogenic fungus isolate, 3 pots were only bioassay bacteria and bioassay fungus isolates and 3 pots were pathogenic fungus and bioassay bacteria and bioassay fungus isolate. As a result of the study, 2 isolates belonging to the Bacillus amyloliquefaciens strain and 1 isolate of T. harzianum has been found effective against A. solani in vivo. It has also been determined that T. harzianum isolate has a positive effect on plant growth. As a result; it is identified that the application of 2 bacteria, 1 fungus isolate, which is most effective, can be used as a biocontrol agent in the control of A. solani in tomato production.