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 KY1

previously isolated from pistachio roots and identified as pathogenic

along with C. rosea isolates F8

F9

and F10

also obtained from the pistachio root region

and 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 isolates

F10 was the most effective

inhibiting the pathogen by 9.04%. In the dual culture assay

the LO41 isolate exhibited the strongest antagonistic effect against the pathogen

with 17.20% inhibition. However

regarding the antagonists’ ability to overgrow and parasitize the hyphae of the pathogen

all isolates

except C. rosea F9

exhibited markedly stronger hyperparasitic activity. In the pot experiment conducted to evaluate the efficacy of the antagonists in soil artificially contaminated with F. solani

the disease severity in the positive control (F. solani KY1) was 72.50%. Following the application of C. rosea isolates F10

F8

LO41

and F9

disease 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%

respectively

indicating that C. rosea F10 was the most effective isolate. Consequently

the capability of C. rosea as a biological control agent against F. solani

a major soil-borne pathogen in pistachios

was further investigated.