Effects of low-temperature water in vase on the hydraulic physiological characteristics and senescence of cut roses (Rosa spp. 'Red Sandra').

This study was investigated the effect of low-temperature water in a vase on the hydraulic physiological characteristics and senescence of cut roses. Freshly harvested ‘Red Sandra’ roses (Rosa spp.) were held in low-temperature (7℃) or ambient-temperature (22.8℃) water and kept in an environment-controlled room (23℃, 60% RH and 12-h photoperiod at 20 μmolㆍm⁻¹ㆍsec⁻¹ PPF) during the vase period. To closely investigate water flow patterns during vase life, stem flux rate, stem diameter, leaf temperature, and leaf boundary layer resistance (BLR) were continuously measured using phyto-monitoring system. Cut roses held in low-temperature water showed a higher rate of water uptake and a higher stem flux rate than those held in ambient-temperature water, which led to the effective maintenance of fresh weight and water balance, and consequently a longer vase life. Placing roses in low-temperature water also resulted in decrease in leaf temperature and BLR and rhythmic changes in stem flux in accordance with water flow. As found in this study, placing roses in low-temperature water speed up water flow by reducing the hydraulic resistance of cut rose stems. This may be resulted from dissolving the air, increasing the cohesion-tension, and the transpiration rate.