Abstract
To compare the effect of lowering solution temperature and the application of germicides at higher temperatures, cut rose flowers were placed in vases containing distilled water (DW) or isothiazolinonic germicides, a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one (CMIT/MIT) solution. Vase solutions were kept at 10 and 23°C under an air temperature of 23°C or at 10 and 30°C under an air temperature of 30°C. Lowering the vase solution temperature significantly extended the vase life of cut roses at an air temperature of 30°C but not at an air temperature of 23°C. Treatment with CMIT/MIT significantly extended the vase life of cut roses at both air temperatures. CMIT/MIT treatment delayed the time to the start of the decrease in fresh weight more than did lowering vase solution temperature at both air temperatures. Stem hydraulic conductance of cut flowers held in DW at 23 and 30°C decreased with time. The decrease in hydraulic conductance was suppressed by CMIT/MIT treatment more than by lowering the vase solution temperatures at both air temperatures. These results show that CMIT/MIT treatment is more effective than lowering the temperature of vase water for extending the vase life of cut roses.
