Effects of different levels of vermicompost on flower yield and its components in ‎genotypes of Damask rose (Rosa damascena Mill.) in Golestan province

In order to investigate the effect of vermicompost on the flower yield and its components in genotypes of Damask rose (Rosa damascena Mill.), a factorial experiment was carried out based on randomized complete blocks design with three replications since 2018-2020 years in the Research Field of Golestan Research Center of Agriculture and Natural Resources. Experimental factors were included three levels of vermicompost (0, 5 and 10 ton ha-1) and four levels of Damask rose genotypes (Kashan, Semnan, Azerbaijan Garbi and Golestan). In this experiment, average plant height, number of flower per plant, flower diameter, fresh weight of flower per plant, dray weight of  flower per plant, yield of fresh flowers and yield of dry flowers were measured for each treatment. The results showed that there was a significant difference between the treatments combinations in terms of all the studied traits (P<0.01). The highest average plant height, maximum number of flowers per plant, highest flower diameter, highest fresh flower yield and dry flower yield were obtained in all genotypes in the maximum application of vermicompost (10 ton/ha). In terms of flower yield, Kashan genotype with fresh flower yield 2319.35 kg/ha and yield of dry flower with 651.22 kg/ha has the highest and Golestan genotype with fresh flower yield 1317.16 kg/ha and dry flower yield with 452.23 kg/ha had the lowest flower yield. Also signification correlation was observed between some of the quantitative traits in this experiment, yield of dry flowers per hectare direct and high relationship with the number of flowers per plant (r=0.95) and fresh flower yield (r = 0.96).