Studies on Weed Fungi Encountered in the Cultivation of Pleurotus eous (Berk.) Sacc.

A sum of 6 fungal species belonging to 6 different genera was found associated with the contaminated beds of Pleurotus eous. These were: Aspergillus niger, Alternaria alternata, Fusarium semitectum, Rhizopus sp., Sclerotium rolfsii and Trichoderma viride. Formaldehyde at the concentrations of 1, 2 and 4 per cent caused cent-per-cent inhibition of Pleurotus eous and S. rolfsii even after 12 hours of exposure period. Fungicide bavistin at the concentrations of 25, 50, 75 and 100 ppm exerted total inhibitory effect on all the contaminants. However, all the fungicides tested in the investigation viz., captan, bavistin and kavach were toxic to Pleurotus eous even at the lowest concentration of 25 ppm. There was no antagonistic reaction between Pleurotus eous and various weed fungi viz., A. niger, A. alternata, F. semitectum, Rhizopus sp., S. rolfsii and T. viride.