Evaluation of fungal antagonists for control of onion white rot in soil box trials

Abstract

Four fungi (Chaetomium globosum, Trichoderma viride, T. harzianum, Trichoderma sp.) were capable of reducing the incidence of onion white rot relative to the untreated control in two soil‐box trials. When applied as a soil additive (sand: bran: fungal homogenate, 1:1:2) at the rate of 0‐1% wheat bran/g dry soil, all fungal isolates provided levels of disease control equivalent to the fungicide (procymidone 0‐5 g a.i./100g seed) treatment. The best results were achieved with the Chaetomium globosum and Trichoderma (C62) isolates which gave 78% and 73% control of white rot. respectively, in trial 1 and 67% and 73% control, respectively, in trial 2. Reduced control was observed when the test fungi were applied as seed coatings or incorporated into alginate pellets.