Biological control of Verticillium wilt of greenhouse cucumber by <I>Talaromyces flavus</I>

Abstract

Talaromyces flavus, a fungal antagonist, was isolated from soil samples collected from cucumber greenhouses in Varamin district, Tehran province, Iran. The antagonistic effects of T. flavus isolates against Verticillium albo-atrum, the causal agent of greenhouse cucumber wilt were investigated under laboratory and greenhouse conditions. T. flavus colonies were recovered after three weeks from soil samples plated on a selective medium. Effects of volatile and non-volatile extracts of T. flavus isolates on V. albo-atrum growth were investigated in the laboratory, and five isolates that inhibited V. albo-atrum more strongly, were selected for greenhouse experiments. The infection index in the greenhouse was compared in a split plot trial with five isolates applied to the soil, the seed, or both seed + soil, arranged in a randomized complete block design with four replications. The greenhouse experiments on the different T. flavus treatments indicated that there was no significant difference among them. Of the five T. flavus isolates, the most effective was Tf-Cu-V-60. The interactions between the T. flavus treatments and the T. flavus isolates showed that the lowest infection index was achieved when the soil was treated with Tf-Cu-V-60. The study showed that T. flavus may control greenhouse Verticillium wilt of cucumber.