Abstract

Compost-inhabiting bacteria were studied for their effect on seedling blight inducing pathogens. Aspergillus niger, Trichoderma harzianum, Bacillus cereus and Bacillus subtilis were the microbes found associated with cow dung, sawdust and rice husk composted soils. Sclerotium rolfsii, Fusarium oxysporum, Pythium aphanidermatum and Macrophomina phaseolina were isolated from blighted seedlings of Cowpea, while S. rolfsii, P. aphanidermatum, Helminthosporium maydis and Rhizoctonia solani were isolated from blighted maize seedlings. When these compost-inhabiting microbes were paired with the seedling blight inducing pathogens, T. harzianum grew on the mycelia of all the test fungal pathogens.  B. cereus reduced the mycelia growth of Sclerotium rolfsii, F. oxysporum, P. aphanidermatum, H. maydis and R. solani, with inhibitory zones ranging from 35.5% to 53.3%.  B. subtilis in culture also inhibited the mycelia growth of all tested pathogenic fungi with inhibitory zones of between 40.0% to 57.8%. The inhibitory activities of the compost-inhabiting microbes might partly be responsible for the efficacy of compost in reducing seedling blight diseases of crops.

Key words: seedling blight, growth inhibition, sawdust, cow dung, rice husk, compost soil.