Abstract:
Biocontrol agents, Trichoderma sp. and Pseudomonas fluorescens isolated from black pepper rhizosphere soil were
identified by microscopic and macroscopic features along with the emission of green fluorescence under ultra violet
radiation. Trichoderma sp. was mass multiplied in tea refuse. Higher number of colony counts were recorded when P.
fluorescens grown in sorghum (Sorghum bicolor L.) and rice (Oriza sativa L.) substrates. As the both biocontrol agents
showed antagonistic ability over Phytophthora capsici under in vitro condition, showing significantly higher level of
growth inhibition, a nursery experiment was conducted using six different combinations of treatments to find out in
vivo biocontrol ability. Treatments applied were Trichoderma sp. treated plants, P. fluorescens treated plants, both
Trichoderma sp. and P. fluorescens treated plants, un inoculated tea refuse applied plants, un inoculated sorghum
seeds applied plants and normal potting mixture with no substrate. Treated plants showed greatest mean plant
height than untreated control (P< 0.05), The highest leaf area of 125.37cm 2 was recorded in P. fluorescens treated
plants while the lowest value of 89.8 cm2 was in untreated control. The highest root volume was recorded in
Trichoderma sp. and P. fluorescens treated plants. Root volume, root dry weight and plants' survival % in treated plants
were significantly (P< 0.05) higher than the control. Shoot dry weight was significantly (P< 0.05) high in P. fluorescens
treated plants. The results indicate that Trichoderma sp. and P. fluorescens enhanced plant survival rate and growth
that could serve as bio control agents and growth promoters.
