Effect of Living Mulch Application on Yield and Yield Components of Sunflower (Helianthus annuus L.) Cultivars and Weed Control

Abstract To evaluate the effect of crop cultivars and living mulch on sunflower yield and yield component and weeds control an experiment was carried out as factorial based on a randomized complete block design with three replications in 2013. Factors were sunflower cultivars (Azargol, Allstar, Farokh) and weed control treatments (weed-free, weed-infestation and intercropping of Fagopyrum esculentum, Medicago scutellata, Vicia villosa as living mulch alone and in combination with one hand-weeding). The results showed that cover crop and weed interference induced significant reduction in the stem height, leaf area index, seed number per head, 100 seeds weight and seed yield of sunflower varieties. Among the traits of crop, leaf area index showed a higher sensitivity to weed interference and cover crops presence than the other traits. In the presence of F. esculentum, M. scutellataand V. villosa grain yield was reduced by 28, 16 and 28 %, respectively, compared to weed-free plot. Weed interference decreased yield of Azargol, Allstar and Farokh by 18, 22 and 33 %, respectively compared to weed-free plot. In the presence of F. esculentum, M. scutellataand V.villosa weed biomass was reduced by 43, 33 and 25 %, respectively, compared to weed infested check. The highest grain yield was obtained from interaction of M. scutellataas cover crop alone and Azargol cultivar. The lowest level of weed infestation was also obtained from interaction of V. villosa followed by one weedingand Azargol cultivar