Investigation of the Effectiveness of Clonostachys rosea (Sch.) Schroers & Samuels on Root Rot Caused by Fusarium solani (March.) Sacc. in Pistachio (Pistacia vera L.)

Abstract

This study was conducted in the Phytopathology Laboratory and controlled-environment growth chamber of Siirt University during 2022-2023 to evaluate the efficacy of Clonostachys rosea against root rot caused by Fusarium solani in pistachio (Pistacia vera L.). The study material included F. solani KY1previously isolated from pistachio roots and identified as pathogenicalong with C. rosea isolates F8F9and F10also obtained from the pistachio root regionand the LO41 isolate obtained from the Phytopathology Laboratory collection. According to the results of the experiment evaluating the antagonistic activity of volatile metabolites produced by C. rosea isolatesF10 was the most effectiveinhibiting the pathogen by 9.04%. In the dual culture assaythe LO41 isolate exhibited the strongest antagonistic effect against the pathogenwith 17.20% inhibition. Howeverregarding the antagonists’ ability to overgrow and parasitize the hyphae of the pathogenall isolatesexcept C. rosea F9exhibited markedly stronger hyperparasitic activity. In the pot experiment conducted to evaluate the efficacy of the antagonists in soil artificially contaminated with F. solanithe disease severity in the positive control (F. solani KY1) was 72.50%. Following the application of C. rosea isolates F10F8LO41and F9disease severity was reduced to 20.00%27.50%37.50%and 52.50%respectively. The pathogen suppression rates of the antagonists were 72.41%62.06%48.27%and 27.58%respectivelyindicating that C. rosea F10 was the most effective isolate. Consequentlythe capability of C. rosea as a biological control agent against F. solania major soil-borne pathogen in pistachioswas further investigated.