BIOHERBICIDAL EFFECTS OF PEPPERMINT (MENTHA-PIPERITA) ON SELECTED WEED SPECIES - A LABORATORY STUDY

The objective of our experiments was to explore the possibilities of e xploiting Mentha piperita HUDS. allelopathic potential to control a gr oup of the selected 10 weed species. Two types of bioagents were used for our purpose, namely Mentha concentrate and pure extracted Mentha p iperita essential oil. Weed seeds were cultured under in vitro conditi ons on the artificial medium according to MURASHIGE and SKOOG (1962) w ith the omission of growth regulators and vitamins, but containing dif ferent concentrations of the above bioagents. The bioagents under stud y exhibited a comparatively strong allelopathic action against the ger minating seeds. In most of the weed species under study the applicatio n of the bioagents brought about a decrease in the percentage of weed seeds germinating and a reduction in shoot and root dry weight compare d to the control. Lower concentrations of the bioagents were found to have a stimulatory effect on the biomass dry weight of some weed speci es, whilst this effect got inhibitory with the increasing bioagents co ncentrations.