Investigating of the Ability of some Cover Crops to Weeds Control

Abstract

To investigate the effect of some cover crops incontroling weed, two experiments were conducted during the fall of 2018 at Namin in Ardabil province both with three replications.The first experiment was conducted in a randomized complete block design using four speacies of winter cover crops consisting of Rye (Secale cereal L.), Hairy vetch (Vicia villosa Roth), Chickling pea (Lathyrus sativa L.) and Hungarian vetch (Vicia panonica L.). The second experiment was conducted in a factorial design, based on randomized complete blocks with two sampling times: (before the end of cover crops growth (when the cover crops were green) and 40 days after the end of cover crops growth (when the cover crops were not green). The results showed that the highest total weed density was related to Hairy vetch and Chickling pea treatments (30.5 and 27 plant per square meter, respectively) and lowest weed density to Rye and Hungarian vetch treatments (17.5 and 22 plant per square meter) respectively. The results also showed that the highest total weed density was recooded from the second sampling time (30.33 plant per square meter) and the lowest total weed density (18.16 plant per square meter) was obtained from the first time of sampling. The highest levels of Shannon-Wiener and Simpson indices were related to the clusters of Hairy vetch, Chickling pea and Hungarian vetch. Rye and Hungarian vetch cover crops, and the first sampling time (presence of green cover crops) were the most suitable types of cover crops and sampling times to reduce weed density. It can be inferred that there is a parallel relationship between plant biomass (establishment, overwintering and regrowth of cover crops) and weed density and dry biomass. Thus, with increasing biomass of cover crops, the density and biomass of weeds would decrease.

Keywords

• density
• leguminous
• residues
• sampling time
• weed control