Trichoderma hamatumEffects on Seed and Seedling Disease Induced in Radish and Pea byPythiumspp. orRhizoctonia solani

Abstract

In laboratory studies, treatment of pea or radish seeds with conidia of T. hamatum in a Methocel slurry protected seeds and seedlings from Pythium spp. or R. solani, respectively, nearly as effectively as fungicide seed treatments. By comparison, treatment of radish or pea seeds with Chaetomium globosum was less effective than T. hamatum. A combination of C. globosum and T. hamatum was less effective on peas than was T. hamatum alone. In soils planted with seeds treated with T. hamatum, numbers of Trichoderma propagules increased approximately 100-fold; replanting this soil once or twice with untreated seeds resulted in lower disease incidence than planting in soils originally planted with C. globosum-treated or untreated seeds. In soils containing T. hamatum, lower densities of R. solani and Pythium were present than in soils without T. hamatum. T. hamatum and C. globosum grew abundantly on treated seeds, while T. harzianum grew little.