PHYTOTOXIC ACTIVITY OF BIOACTIVE COMPOUNDS FROM FOUR PLANTS AGAINST SELECTED WEEDS IN AGRICULTURE

Aim of the Study. Heavy doses of synthetic weed control chemicals have caused herbicide resistance in weeds. Natural com pounds produced by living organisms constitute a wide field for ecologically safe herbicides. The experiments were designed to test allelopathic potential of hexane extracts of selected plants against common weeds in agriculture viz. Euphorbia helioscopia, Rumex dentatus, Phalaris minor, Avena fatua and Chenopodium album. Materials and methods. Allelopathic potential of Carica papaya, Rhazya stricta, Lantana camara and Pinus roxburghii hexane extracts against weeds was determined at 100%, 75% and 50% concentration on soil, filter paper and agar. Parameters adopted for assessing allelopathic potential were the germination (%) and the length of seedling (cm). Data analysis was performed using the Statistica 9 software. Results and Conclusion. The results indicated that R. stricta, C. papaya, L. camara and P. roxburghii hexane extracts possesses suppression effects against weeds among which L. camara had the most conspicuous inhibition effects on selected weeds. The inhibitory effects of germination and seedling growth were in order R. stricta > L. camara > C. papaya > P. roxburghii. Field analysis to assess the phytotoxic ability of these species to be used as herbicide is recommended.