Description

Abstract: A lignite-stillage carrier system was tested for applying bimontrol agents to the soil. Lignite was ground into granules (425-2,000 pm) and twice amended with 50% (v/ v) t hin liquid stillage (TLS), a by-product of ethanol production. Two isolates of Cliocludrum virens and one isolate of Trichoderrna harzianum were used as test organisms. Seven days after inoculation, the colonized granules were air-dried and stored at 20 C. After 4 ma of storage, fungal viability remained >90% as determined by plating of granules. Colonized lignrte-stillagecarrier granules were applied in-furrow at a rate of 9.15 glrn to soil in growth boxes artificially infested with Rhizoctania solani. Root rot ratings and raot and shoot dry weights revealed positive effects of the bioconrrel agents and carrier. One isolate of G. virens significantly lowered the incidence of damping-off and root rot caused in peanuts by R. solani; however, the incidence of damping-off and root rat were still significantly higher than in the noninfested control. Thin

liquid stillage supported significant production of glioroxin by G. virens in broth culture. Gliotoxin was not an important factor in suppression of I?. soloni; a gliotoxin-producing isolate of G. wrensdid nat lessen damping-off or root rot as effectively as a non-gliotoxin-producine isolate.