Evaluation of different levels of irrigation and cultivation substrate on the growth indicators of cut roses

In order to evaluate different levels of irrigation and growing media on the growth indices of Samurai cut rose in soilless cultivation conditions, this study was conducted as a split-plot experiment based on a randomized complete block design with four replications in the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad. The treatments in this study included four levels of water regime (60, 80, 100, and 120% of irrigation requirement) as the main plot and three growing media (perlite, perlite-cocopeat with a volume ratio of 3:1, and perlite-vermiculite with a volume ratio of 3:1) as the subplots. The results of the experiment showed that plants in the 100% (control) and 120% irrigation regimes, due to the provision of optimal water consumption and sufficient nutrients, had better performance in terms of rose branch length, rose fresh and dry weight of rose branch, stem diameter and bud diameter of rose, number of rose branches harvested, relative leaf water content, and chlorophyll a content compared to plants in water stress conditions. This is while water stress did not affect the rose bud length trait. Also, the effect of the growing medium on all measured traits except branch length was not significant. In addition, the interaction of the water regime treatment in the growing medium on any of the measured traits except the rose bud diameter had no significant effect. In general, optimal water supply led to improved vegetative and physiological traits in the plant; therefore, in the cultivation conditions of the Samurai rose cultivar, 100% and 120% treatments are recommended as water regime levels.