Determination of the effect of Trichoderma Pers. on root rot caused by Rhizoctonia Solani Kühn. in pistachios

Due to reasons such as environmental pollution caused by chemical pesticides used in agriculture, residue problems and the difficulty of chemical control of soil pathogens, alternative methods are being investigated to control some plant diseases. Biological control is a method developed as an alternative to chemical control. Trichoderma species are known to be the most used antagonists in biological control. This study investigated the effectiveness of some Trichoderma species against Rhizoctonia solani through volatile metabolites, using a dual culture method and in artificially contaminated potting soil in 2022-2023. The study showed that Trichoderma sp. FT1 isolate suppressed the pathogen by volatile metabolites with a rate of 33.88%. In the dual culture method, the Trichoderma harzianum TUZ16 isolate demonstrated strong hyperparasitic properties, inhibiting the pathogen by 70.97%. It was determined that the antagonists T. harzianum TUZ16, Trichoderma virens İB1, Trichoderma viride VG18, and Trichoderma sp. FT1 suppressed the pathogen in the plant by 66.66%, 60.00%, 56.66%, and 43.33%, respectively in pot study.