Abstract:
Tea plants are subjected to serious fungal diseases which cause significant yield losses. The frequent use of chemical fungicides to control causative pathogens may lead negative impacts to both human and environment. Trichoderma species are noted for their bio control capabilities against many economically important plant pathogens. Hence, an attempt was made to investigate the antagonistic effect of three (03) Trichoderma strains (Trichoderma asperellum, Trichoderma viride and Trichoderma harzianum) on six (06) fungal pathogens (Colletotrichum camelliae, Pestalotia theae, Calonectria theae, Rhizoctonia solani, Phomopsis theae, Macrophoma theicola) of Tea. Isolated pathogens of Tea and tested antagonists were identified at their species level based on their phenotypic traits such as colony morphology, growth rate and vegetative and reproductive structures in In-vitro conditions and the pathogenicity of each isolates were confirmed using pathogenicity test at In-vivo conditions. Antagonistic effect of tested Trichoderma strains against isolated pathogens were calculated in terms of Percentage of Inhibition resulted from the Dual Culture Test. The percentage of inhibition of Trichoderma asperellum, Trichoderma viride and Trichoderma harzianum against all six pathogens were calculated in-between 63.41% to 79.76%, 75.75% to 88.88%, and 73.11% to 82.51% and each were significant at p values 0.05 as 0.0000, 0.018 and 0.001 respectively. In conclusion, all three antagonists showed more than 50% antagonism over the six pathogens concerned as they grew in faster rate than the pathogens and the Trichoderma viride was identified as the best antagonist against all tested pathogens of Tea. |
