BIO-HERBICIDAL EFFICIENCY OF WITHANIA SOMNIFERA AGAINST IMPORTANT HIMALAYAN WEEDS

摘要

Objective: The aim of the study was to evaluate the bioherbicidal activity of Withania somnifera against germination and growth of noxious weeds of Himalaya i.e. Ageratum coenyzoides, Chenopodium album and Achyranthus aspera in a laboratory and foliar spray bioassay which will act as a tool of weed management in the Himalayan region. Methods : Root, stem and leaf aqueous extract of Withania somnifera at 100 concentration were applied to determine their effect on the seed germination and seedling growth of tested weeds under laboratory condition. Foliar spray bioassay was carried out by spraying extracts of Withania somnifera on three-month-old seedlings of weeds for two months. Germination and growth of weeds were assessed using growth parameters into account i.e. germination percentage, stem length, root length, fresh weight, dry weight, no of shoot branches and no of root branches. Results: The results revealed that all the aqueous extracts markedly suppressed germination and seedling growth of A. coenyzoides, C. album and A . aspera. Withania extracts remarkably effected germination, the growth of Ageratum coenyzoides in comparison to other studied weeds . The leaf extract of Withania was more pronounced than stem and root extracts in germination assay. Infoliarspray bioassay, aqueous leaf extracts of 100 w/v concentrations were sprayed on three month old seedlings of weeds at an interval of 5 d. All the aqueous extracts significantly suppressed shoot length, root length, fresh weight and dry weight of Ageratum coenyzoides, Chenopodium album and Achyranthus aspera seedling. In foliar spray bioassay, leaf extract suppressed the stem length, root length, fresh weight, dry weight, no. of root branches and no of shoot branches of studied weeds more commendably than stem and root extract. The suppression of growth parameters could be attributed to the presence of phytochemicals present in the extracts of Withaniasomnifera . Conclusion: The present study concludes that Withania somnifera contain bio-herbicidal compounds in leaf, stem and root as plant extracts adversely affect weed growth of studied weeds. Henceforth the strategy bio-control of weed is a safe and effective method which could prove a milestone in weed management in Mid-Himalaya.