In vitro screening of biological and chemical agents together on the growth of Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. causing inflorescence die back in arecanut

Colletotrichum gloeosporioides is a destructive pathogen of many crop species causing diseases in many annual, biennial and perennial plants. A study was undertaken to find out the effect of biological and chemical agents together on the growth of C. gloeosporioides causing inflorescence die back in arecanut at the Department of Plant Pathology, CPCRI, Kasaragod. To reduce the release of chemical pesticides to the environment, integrated control strategies have been adopted extensively by combining both bioagents and chemical agents. So in the present study in vitro experiments were conducted with two compatible Trichoderma sp. viz., Trichoderma virens and Trichoderma viride and fungicides viz. Blitox 50 W and Mixol 72. The results indicated that all the treatments had a significant inhibitory effect on the growth of C. gloeosporioides and reduced its colony diameter. High percent inhibition was found when 0.05% of Mixol 72 was used with T. virens (87.61%). The least inhibition was shown by T. virens+0.05% Blitox 50 W (80.95%). It is concluded that the combination of bioagents with fungicides provided higher disease suppression than achieved with fungicides and bioagents when used alone.