Changes the vegetative characteristics and grain yield of sunflower (Helianthus annuus L.) cultivars in the presence of fenugreek as living mulch

This study was done to investigate the response of vegetative traits of sunflower cultivars in the presence of fenugreek as living mulch at Razi University in 2017. The experiment was conducted as split-plot based on randomized complete block. First factor was the sowing fenugreek at four levels (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). Results showed that with planting of fenugreek before sunflower, height, stem weight, number of leaves, leaf weight, leaf area index, content of chlorophyll a, b and total of chlorophylls were decreased by 26.4%, 62.1%, 24.8%, 68.5%, 63%, 7.4%, 3.7% and 6.8% compared to control, respectively. The lowest relative water content was also obtained by planting fenugreek before sunflower (65.2% and 52.7% at the 1/3 of primary growth season and flowering stages). The effect of presence mulch under the simultaneous and 15 days after sunflower conditions had no significant effect on growth characteristics of sunflower compared to control condition. Among thecultivars, the highest of grain yield was assigned to Lacomka (3426 kg/ha). However, Progress had the highest height (212 cm), stem weight (523 g/plant), leaf number (25.5 per plant), leaf weight (157.4 g/plant), leaf area index (6.2) and relative water content (77.8% and 70.5% at the 1/3 of of primary growth season and flowering stages). The highest of leaf area ratio (0.013 m2/g) and carotenoid content (2.5 mg) belonged to Farrokh.