The Effect of Cover Crops on Weeds Control and Essential Oil Yield of Mint (Mentha piperita L.)

Planting of narrow leaf cover crops may have an important effect in reducing the use of herbicide. Cover crops, therefore, are an effective tools in the non-chemical weed management in sustainable agriculture. To evaluate the effect of cover crops on weeds control and essential oil yield of mint, a factorial experiment based on randomized complete blok design with three replications was conducted at the Research Field Mohagheghe Ardabili University, Iran, in 2015. First factor consisted of: spring wheat, spring barley, winter rye, winter wheat, winter barley, mixed winter rye + winter barley and second factor consisted of: cutting mulch near ground, heading living mulch 20-30 cm. from ground and killing ground cover by herbicide. Also, two controls were: without cover crop and weeding without cover crop and without weeding, inside conducted experiments. The results showed that the main effect of cover crops management had significant effect on peppermint content and dry weight and density of weeds. Comparison of interaction effects showed that highest leaf oil yield in heading living mulch of winter wheat, undercutting spring barley and winter rye was (52g/h). On the average in three stages of sampling the percent biomass control of redroot pigweed andfield bindweed in undercutting mulch, heading living mulch, killing cover crops with herbicide were 38% and 66% and their density control were 44% and 70%, respectively