Effects of different planting densities and organic fertilizers on yield characteristics of Satureja spicigera (K.Koch) Boiss. under rainfed conditions

To investigate the effects of planting density and organic fertilizers on the yield traits of Satureja spicigera (K.Koch) Boiss. under the Kermanshah rainfed conditions, an experiment was conducted as a split-plot based on complete randomized block design (CRBD) with three replications in Kermanshah Agricultural and Natural Resources Research Center in 2016-2020 crop years. The main factor and sub-factor were fertilizer (rotten cow manure, enriched straw, and field soil (control)) and plant density (2.66, 4, and 8 plants.m-2), respectively. To have the desired densities, plants were grown with a distance of 50 cm between the rows and 25, 50, and 75 cm on the rows. The results showed that the traits including diameter, height, canopy area, fresh and dry weight of plant, fresh and dry yield per hectare, and essential oil yield per hectare were significantly different between the years, plant densities, and fertilizer treatments. The highest fresh yield (3639.3 kg.ha-1) was obtained in the rotten cow manure+ high plant density treatment and the highest dry yield (2105 kg.ha-1) and essential oil yield (72.59 kg.ha-1) in the enriched straw+ high plant density one. The results showed that the best fertilizer and plant density treatment for S. spicigera was straw enriched with ammonium sulfate and 8 plants.m-2.