Abstract:
Trichoderma has been widely studied for their
biocontrol ability, but their use as biocontrol agents in
agriculture is limited due to the unpredictable
efficiency which is affected by biotic and abiotic
factors in soil. Isolates of Trichoderma from Embu
soils were evaluated for their ability to control
Fusarium oxysporum f. sp. phaseoli., in vitro and
promote seedling growth in the greenhouse. Bioassays
were run using dual cultures and diffusible compound
production analysis. The Trichoderma isolates
significantly (p < 0.01) reduced the mycelial growth of
the pathogen. The principle mechanisms of niche
competition, mycoparasitism, and antibiosis were
observed in growth of the pathogen mycelium in the
presence of Trichoderma spp., through development of
inhibition zones. There was coiling of hyphae around
the pathogen mycelium coupled by lysising of cell
wall Trichoderma spp., where T. reesei and T. koningii
were the most effective isolates. Studies were
indicative of the synergistic ability of Trichoderma
spp., being an effective biocontrol of bean seedlings
against Fusarium wilt while also promoting plant
growth