Effectiveness of cover crops on iceberg lettuce weed control

Nowadays, high-quality standards in agricultural products are one of the most important demands of human health and using herbicides for weed control is conflict with this aim, so controlling weeds by other methods can help farmers to produce chemical free crop production. A factorial experiment was conducted based on a randomized complete block design with three replications in the research farm of the Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran in ۲۰۱۸. Experimental treatments included: monoculture and intercropping of rye (Secale cereal L.), chickling pea (Lathyrus sativus), control (no cover crop), weed control (hand-weeding) once or two times, and a control (weedy) during the growing period of the main crop (lettuce). Intercropping without hand weeding increased lettuce yield by ۵۷.۲۹% compared to no cover crop control. The highest lettuce leaf number (۲۱.۵۵ and ۲۱.۴۴), stem diameter (۴.۱۸ and ۴.۱۵ cm), and the head diameter (۲۲.۶۴ and ۲۲.۱۰ cm) were obtained from intercropping and chickling pea monoculture. Intercropping and monoculture of chickling pea in comparison with control treatment or without cover crops increased ۱۲.۴۴% and ۱۱.۸۰% stem diameter, ۴۵.۰۹ and ۴۳.۷۵%, head diameter, and ۲۴.۲۲ and ۲۳.۸۳% the number of leaves, respectively. Also, the highest plant height (۱۹.۹۳ and ۱۹.۸۱ cm) belonged to intercropping and rye monoculture, respectively. Our results showed that success in weed control depends on the amount of cover crops biomass obtained by the monoculture or intercropping system which can reduce the hand weeding times.

کلیدواژه ها:

Cover crops ، Lettuce ، Weed ، Yield