Evaluation of Different Irrigation Levels and Media on Growth Properties of Cut Rose (Rosa hybrida cv. Samurai) under Soilless Culture Conditions

Rose is one of the most important ornamental plants that is widely cultivated in many countries. The optimal growth and development of commercial cut rose varieties is essential to supply the water needed for plants. If the water level is reduced at different stages of production, it can have damaging and damaging effects on the vegetative properties of the cut rose. Therefore, accurate estimation of water requirement and adaptation of irrigation program based on water requirement of the plant and its growth conditions can improve water use efficiency, avoid stress and control production.

In order to evaluate different levels of irrigation requirement in combination with crop media on vegetative characteristics of rose CV. Samurai, a greenhouse experiment was conducted as split plot based on randomized complete block design with four replications in greenhouse conditions of Ferdowsi University of Mashhad. The need irrigation of the plant 120%, 100%, 80%, 60% and sub plot consisted of three different substrate levels (Perlite, perlite_cocopeat 1:3, perlite_Vermiculite 1:3). The traits included a stem length, branch diameter, flower bud length and diameter, fresh and dry weight of flower bud, number of flowering branches, chlorophyll a, b, relative leaf water content (RWC).

Results showed that among the experimental treatments, water stress treatment had significant effect on all measured traits except flower bud length. However, culture medium treatment and interaction of media*water stress did not affect all measured physiological and biochemical parameters except for branch length and flower bud diameter. The results of this experiment showed that the 120% and 100% water regimes significantly increased the measured physiological and biochemical traits (shoot length, fresh and dry weight of flower shoot, shoot diameter, number of shoots, RWC, chlorophyll a) were included in this study. Whereas the 60% aqueous regime had adverse effects on the parameters considered. Whereas the highest amount of chlorophyll b was obtained in the 60% aqueous regime.

In the present study, the results indicate that water stress has adverse effects on all vegetative characteristics of cut roses, therefore, it is suggested that the aquatic requirement of the plant in order to achieve high quality roses be accurately estimated. Also, the flower bud length traits are not significant at water stress levels, because the plant roots are in close contact with water under cultivated conditions and respond to water stress by improving the electrical conductivity in the plant. Therefore, it is recommended that due to the negative effects of water stress on the quantitative and qualitative traits of rose, special attention should be paid to the problem of accurate estimation of water requirement and optimal water supply. Therefore, it is important to improve the vegetative and physiological traits of roses in non-soil conditions using appropriate cultivation for future studies in order to achieve desirable results.