In Vitro Evaluation Certain Plant Extracts Against Glomerella cingulata Causing Brown Blight Disease of Tea

Brown blight a foliar disease of tea caused by the fungus Glomerella cingulata. An ecofriendly approach and alternative to chemical control measures of this disease, various plant extracts and efficient biocontrol agents are being involved to minimize the disease pressure. In the present study, aqueous crude extracts of 50 plants were tested against G. cingulata under in vitro. Results revealed that the extract of Pongamia pinnata was found to provide 100% growth inhibition of G. cingulata at the concentration of 10% followed by Syzigium aromaticum (81.87%), Acorous calamus rhizome (80.62%), Parthenium hysterophorus (78.75%), Citrus melon (78.12%), Ageratum conyzoides (78.75%), Allium sativum (73.10%) and Abutilon indicum (71.15%). Whereas the extracts of Piper nigrum, Cinnammoum xanthocarpum and Acorous calamus leave at 10% were ineffective against the pathogen.