The Effect of Winter Cover Crops on Plant Density, Biomass of Weeds and Potato Yield (Solanum tuberosum L.)

To investigate the effect of winter cover crops on plant density, biomass of weeds and potato yield an experiment based on complete randomized block design with three replications was performed at Yingjeh Mullah Mohammad Reza village in Namin, Ardabil, Iran, in 2018. Treatments were rye (Secale cereal L.), hairy vetch (Vicia villosa Roth), chickling vetch (Lathyrus sativa L.) and Hungarian vetch (Vicia panonica L.). The results showed that the highest dry biomass was obtained from rye treatment (696 g.m-2), the lowest plant densities from its first and second sampling (9.3 and 23.6 plants per square meter, respectively. The lowest fresh and dry weed biomass from first sampling (175.8 and 52.2 g.m-2, respectively) were due to rye treatment. In addition, the lowest fresh and dry biomass of all weeds in the second sample indicated (377 and 134 g.m-2, respectively) were related to rye treatment. Also, the results indicated that the highest and lowest biomasses of weeds in both samples were related to the treatment of hairy vetch and chickling pea. The yield of potato tuber was not affected by the cover crops residues, and the effect of the cover crops did not different potato tuber yield significantly. The results show that rye has a significant effect on reducing the density, fresh and dry biomass of weeds in two sampling stages, but reduction in biomass of weeds does not necessarily indicate a positive effect of cover crops in the short term on improving crop yields.