Application of Fenugreek Living Mulch and Cultivar for Weed Control in Sunflower

Application the living mulch as a non-chemical method to weeds control helps to improve sustainable agricultural systems management. Thus, the effect of sowing fenugreek as living mulch on different dates in weed control and sunflower yield was investigated at Razi University during the 2016-2017 growing season. Experiment was performed as factorial on randomized complete block design with three replications. First factor was the sowing fenugreek at four levels as control (without living mulch), 15 days before sowing of sunflower, simultaneous sowing with sunflower, 15 days after sowing of sunflower and the second factor was three sunflower cultivars (Progress, Farrokh, Lakomka). The results showed that mulch sowing reduced biomass and density of weeds at the beginning and end of the growing season. The Progress cultivar in weed control was superior to other cultivars. Competitive index for Progress, Farrokh and Lakomka cultivars was 1.67, 0.5 and 0.89, respectively. The weeds in non-control treatment (without weeding) reduced grain yield by 75.8%. In non-control condition, the presence of mulch could not improve yield. But in control condition, sowing of fenugreek simultaneous and after sunflower improved yields by 1083 and 703 kg.ha-1, respectively. In control and non-control conditions sowing of fenugreek before sunflower led to significant decrease of yield. In control condition, the Lakomka yield (3426 kg.ha-1) was higher than Progress and Farrokh yields. However, in non-control condition the difference of cultivars was not significant. It seems that in non-control condition, weeds competition with sunflower prevents from the positive effect of mulch and cultivars superiority in yield production.