EVALUATING THE PHYTOTOXIC EFFECTS OF SOME PLANT SPECIES OF SEMI-ARID REGIONS

Abstract

The most effective method for weed control is the use of herbicides. However, the scope of this method is narrowing down due to herbicide-resistant weeds and the non-availability of new chemistry herbicides. Hence, to explore natural weed management options, the herbicidal potential of three weed species extracts namely Opuntia ficus-indica, Murraya koenigii and Dryopteris felix-mas were evaluated in lab and wirehouse experiments. A completely randomized design with factorial arrangements was used for lab and completely randomized design was used for wirehouse experiments. Each experiment was repeated twice with four replications each time. Data pertaining to seed germination, seedling growth and physiological traits of crops and weeds were recorded using standard procedures. Data indicated that aqueous extracts of tested species depicted more phytotoxicity than N-hexane extracts against germination and seedling growth of lettuce in the lab experiment. Aqueous extract of Opuntia ficus-indica completely inhibited lettuce seed germination whereas, N-hexane extract of the same species has least effect on germination and germination traits like mean germination time, time taken to 50% germination, germination index. The aqueous extract of O. ficus-indica resulted in minimum lentil, mashbean, mungbean, parthenium and Trianthema portuclacastrum seedling leaf area, chlorophyll content, shoot, root length, dry weight and maximum electrolyte leakage. The foliar application of O. ficus-indica, M. koenigii and D. felix-mas water extracts on seedlings of lentil, mashbean, mungbean, parthenium and T. portuclacastrum followed the phyto-toxicity order O. ficus-indica aqueous extract ˃ D. felix-mas aqueous extract ˃ M. koenigii aqueous extract. The growth-inhibitory demonstrations of O. ficus-indica extract suggest that active substances with herbicidal properties are present in this plant which could be exploited as natural weedicide.