Investigation the use of living and non-living mulches in weed control of coriander (Coriandrum sativum L.)

Weeds are the most important limiting factors in agricultural systems and the use of mulch is considered as a suitable solution in the ecological management of weeds. In order to evaluate the coriander yield and its weed control, a factorial experiment was conducted at the research farm of the Faculty of Agriculture, University of Zanjan in 2020. The first factor was the types of mulches including ratios of 100 % (40.0 kg ha-1), 66 % (26.4 kg ha-1), and 33 % (13.2 kg ha-1) of clover (Trifolium alexandrinum L.) and 100 % (20.0 kg ha-1), 66 % (13.2 kg ha-1), and 33 % (6.6 kg ha-1) of alfalfa (Medicago scutellate L.) as living mulches, wheat straw (Triticum aestivum L.) (one kg m-2) as a non-living mulch, and a non-mulched treatment and the second factor was weed control including complete weed control, once-weed control and non-weed control. The results showed that the effects of the treatments of mulch type and weed control were statistically significant on the components of yield and yield of coriander. The highest grain yield (1601.4 kg ha-1), biomass yield (3901.0 kg ha-1) and essential oil yield (3.35 kg ha-1) were recorded in wheat straw mulch under complete weed control conditions. Clover at densities of 100 % and 66 % caused suffocation and complete destruction of coriander plants. Therefore, the grain yield and biomass production of coriander in these treatments were equal to zero. Alfalfa at low densities had no significant effect on weed control. Complete control of weeds caused a significant increase in all evaluated traits in coriander. The results of the present study showed that wheat straw mulch is a suitable solution for controlling coriander weeds, which not only does not interfere with the growth of coriander but also causes effective control of its weeds. Therefore, considering the importance of integrated control of weeds in sustainable agricultural systems, the use of wheat straw mulch can be introduced as one of the strategies to reduce the use of chemical pesticides and reduce environmental pollution.