Effect of various chemical and organic mulch types on weed frequency, and growth and yield characteristics of saffron in Qaenat region

In order to study the effect of different chemical and organic mulch types on density and biomass of weed and some agronomical characteristics of saffron (Crocus sativus L.), an experiment was conducted based on randomized complete block design with three replications at Qaen region in during 2018-2019. The experimental treatments were application of various mulch types for weed control (no weed control, hand weeding, transparent polyethylene, black polyethylene, beeswax waste, residues of grape leaf, wheat straw, pomegranate leaf, pistachio leaf, barley straw and saffron corm dunnage). The results showed that all the treatments except transparent polyethylene significantly reduced the number of species, density, dry weight and shannon diversity of weed compared to no weeding treatment. The lowest dry weight of weed was related to black polyethylene (52.22 g m-2) and wheat straw (123 g m-2) mulches. Application of all the mulches except transparent polyethylene caused a significant increase in corm, flowers and stigmas yield of saffron compared to non-weeding conditions. Beeswax waste and wheat straw had the highest number of flowers (151 and 135 flowers m-2) and stigma yield (4.89 and 4.32 kg ha-1), respectively. Black polyethylene, pomegranate leaf and grape leaf did not show a significant difference with hand weeding in terms of growth and yield of saffron. In general, the results confirmed that the application of all the studied mulches with the exception of transparent polyethylene led to appropriate weed control and improving saffron yield characteristics compared to no weed control treatment and are recommended to farmers.