ENHANCEMENT OF SNAP BEAN EMERGENCE BY GLIOCLADIUM-VIRENS

Emergence of snap beans (Phaseolus vulgaris L.) in field soil in 1993- 95 was enhanced by the biocontrol agent Gliocladium virens J.H. Miller , J.E. Giddens, & A.A. Foster. The fungus was applied to each seed at planting as a wheat bran alginate pellet formulation in 1993-95. Preem ergence and postemergence damping-off were reduced in plots treated wi th G. virens. Nodulation on the roots of treated plants was numericall y increased in 1993 and 1994 compared to nontreated plots. Efficacy of G. virens was reduced in 1995, probably due to high ambient temperatu res at the time of planting. In plots with reduced stand, leaf area wa s increased and yield on a per-plant basis was larger than in plots wi th a better stand. Total yield also was increased in plots with fewer plants, except in 1994. Fungi isolated from failed seedlings included Fusarium spp., Pythium spp., and Rhizoctonia solani Kuhn.