Title: Efficacy of Trichoderma isolates for control of Pestalotiopsis theae the causal agent of grey blight of tea

Biography:

Lizzy Mwamburi is a professor of plant pathology and invertebrate pathology at the University of Eldoret, Kenya. She has expertise in evaluation of entomopathogenic microbes for control of animal  and plant pests and diseases. Her passion for improving health through biological control, spans from years of experience of research, evaluation, teaching and supervision in education and research institutions.

Abstract

The tea industry plays a key role in the agriculture sector and the economy of Kenya contributing about 11% of the agriculture sector's contribution to Gross Domestic Product. Pestalotiopsis theae the causal organism of grey blight of tea is a serious problem of tea. Because of concerns of high toxicity and environmental safety, chemical residues in made tea alternatives to chemical control are needed. The antagonistic potential of five Trichoderma isolates (T4, T5, T13, T17 and T26) was evaluated for biological control capacity of Pestalotiopsis theae the causal organism of grey blight of tea. The genus Trichoderma is a hyperparasitic fungus that uses different mechanisms of biological control. Three antagonistic mechanisms employed by Trichoderma were evaluated. The results showed that all selected Trichoderma isolates were significantly effective (p≤0.05) in the control of P. theae. On dual plate culture the maximum inhibitory activity of the Trichoderma was exhibited by T17 at 50.36% compared to the least T4 with 39.42%. For volatile metabolites test, T3 was the most inhibitory (55.83%) and T5 the least inhibitory (31.25%). Results from non- volatile metabolites of Trichoderma indicated that T3 and T17 exhibited highest inhibition to the growth of Pestalotiopsis at 68.40% and 67.16% respectively while T5 was least at 14.07% inhibition. From the results we can conclude that the efficacy of the Trichoderma isolates depended on the mechanism considered and that overall T17 was the most efficacious of the Trichoderma sp isolate in the control of Pestalotiopsis theae.