The cut flower industry faces many challenges due to the difficulty in producing flowers with a long postharvest vase life. To ensure a longer vase life, growers must carefully regulate postharvest conditions and postharvest handling methods.
Water uptake is one of the most important factors in improving the length of vase life of cut flowers (Halevy and Mayak, 1979). As the leaves on the flowers transpire, water is drawn up through the xylem. If this process is impeded by a vascular blockage or accelerated by increased stomatal opening, transpiration will exceed uptake and water deficiency will occur. Thus, solutes are frequently added to vase solutions such as 8-hydroxyquinoline citrate (8-HQC), which can increase water uptake (van Doorn, 1997). To ensure quality product, rose growers, wholesalers, and retailers should understand the effects of additives or preservatives in vase solutions on rose vase life. While adding sucrose to a vase solution will increase vase life, it also allows increased bacterial proliferation that then requires the addition of antimicrobial compounds to vase solutions to minimize occlusions in the stem from bacteria. For example, the addition of 8-HQC to vase solutions reduced bacteria levels found in the bottom 5-cm segment of ‘Sonia’ rose stems from 840,000 cfu/g fresh weight to less than 120 cfu/g fresh weight (van Doorn, 1990). A low pH solution produced by the addition of sodium hypochlorite and a pH 3.0 buffer also reduced bacteria levels and increased water conductance in several rose cultivars (Marousky, 1971; van Doorn, 1990). Sucrose decreased water absorption in ‘Better Times’ roses; however, Marousky (1969, 1971) determined that sucrose extended vase life. In ‘First Red’, vase life increased over the control when held in a vase solution containing up to 1.5% sucrose and vase life declined with higher concentrations of sucrose up to 3% (Singh et al., 2003). Bhattacharjee (1994) found in a study on 10 rose cultivars that the use of a preservative solution containing 300 mg·L−1 8-HQC and 1% sucrose increased vase life vs. using distilled water. The extent of the increase varied by cultivar from 1.0 to 2.7 d. Ketsa et al. (1993) found that using a holding solution containing 5% sucrose and 20 mg·L−1 silver nitrate significantly improved the vase life of ‘Eiffel Tower’, ‘Swartmore’, and ‘Yankee’ roses, but did not improve vase life of ‘King’s Ransom’ or ‘Confidence’.
Ethylene, a naturally occurring plant hormone, is another postharvest factor that can negatively impact flower quality. Thus, some producers use antiethylene agents to minimize its effects (Dole and Wilkins, 2005). The effect of ethylene and antiethylene agents on cut rose flowers is varied and appears to be cultivar dependent. On a test with 38 cut rose cultivars, 1 μL·L−1 exogenous ethylene shortened vase life of 27 cultivars, impeded the rate of flower opening in six cultivars, and had no effect on five cultivars (Macnish et al., 2010). RueySong et al. (2001) noted that a 0.1- to 2-μL·L−1 exogenous application of ethylene significantly decreased vase life in ‘Golden Medal’ cut roses but had less of an effect on ‘Grand Gala’ vase life. Ethylene at 0.5 μL·L−1 inhibited (three cultivars), accelerated (14 cultivars), or had no effect (five cultivars) on flowering opening (Reid et al., 1989). For the effects of antiethylene agents, Reid et al. (1989) noted that STS could overcome the effects of exogenous ethylene. Singh et al. (2004) found that STS improved the vase life in three of seven rose cultivars tested, and Macnish et al. (2010) showed that STS could prevent an ethylene-induced drop in vase life in three ethylene sensitive cultivars.
Contrasting reports exist on the efficacy of 1-MCP. Philosoph-Hadas et al. (2005) found that treating stems with 0.4 μL·L−1 1-MCP for 4 h increased vase life for rose cultivars Pink Tango, Jazz, Frisco, and Golden Gate compared with ethylene-exposed control stems, and Macnish et al. (2010) found that various types of 1-MCP treatment prevented the negative effects of exogenous ethylene. However, Chamani et al. (2005) found that treating stems with 1 μL·L−1 1-MCP for 2 h did not improve vase life in ‘First Red’. The effects of ethylene and antiethylene agents on water uptake are also not known.
The application of postharvest research to the industry has always been a concern of researchers, and there appears to be limited information about how the number of stems per vase and recutting time impacts postharvest quality. Restrictions on availability of plant materials and time to collect data usually limit the number of stems per replication in research. Commercial cut flower growers, wholesalers, and retailers typically group rose stems in bunches of 10 or more and also place dozens of bunches in each bucket as the flowers are harvested, processed, and marketed. For postharvest evaluation, commercial tests are usually conducted using whole bunches with 10 or more stems, while university research often uses replications of one, three, or five stems per vase. Also, after receipt of roses, stems are usually recut to increase vase life (Dole and Wilkins, 2005). However, questions still remain about how changing drying time after recutting the stem, drying time before recutting the stem, and the amount of the stem recut impacts postharvest floral quality.
Therefore, the objectives of this research were to quantify the effects of 1) various vase solutions, 2) application of exogenous ethylene and antiethylene compounds before and after shipment, 3) stem number in a vase, and 4) postharvest dry storage on the postharvest performance of several cut rose cultivars.
Al-Humaid, A.I. 2004 Silver thiosulfate prolongs vase life and improves quality of cut gladiolus and rose flowers J. Food Agr. Environ. 2 296 300
Carpenter, W.J. & Rasmussen, H.P. 1973 Water uptake rates by cut roses (Rosa hybrida) in light and dark J. Amer. Soc. Hort. Sci. 98 309 313
Chamani, E., Khalighi, A., Joyce, D.C., Irving, D.E., Zamani, Z.A., Mostofi, Y. & Kafi, M. 2005 Ethylene and anti-ethylene treatment effects on cut ‘First Red’ rose J. Appl. Hort. 7 3 7
Doi, M., Miyangawa-Namao, M., Inamoto, K. & Imanishi, H. 1999 Rhythmic changes in water uptake, transpiration and water potential of cut roses as affected by photoperiods J. Jpn. Soc. Hort. Sci. 68 861 867
Dole, J.M. & Wilkins, H.F. 2005 Floriculture principles and species. 2nd ed. Pearson-Prentice Hall, Upper Saddle River, NJ
Fanourakis, D., Pieruschka, R., Savvides, A., Macnish, A.J., Sarlikioti, V. & Woltering, E.J. 2013 Sources of vase life variation in cut roses: A review Postharvest Biol. Technol. 78 1 15
Hettiarachchi, M.P. & Balas, J. 2005 Croton (‘Codiaeum variegatum (L.) Blume Excellent'): An evaluation of foliage performance after shipment and of vase water treatments to maintain vase life Acta Hort. 669 343 349
Ichimura, K., Kojima, K. & Goto, R. 1999 Effects of temperature, 8-hydroxyquinoline sulphate and sucrose on the vase life of cut rose flowers Postharvest Biol. Technol. 15 33 40
Ketsa, S., Thampitakorn, F. & Piluek, C. 1993 Effects of silver nitrate and silver thiosulfate on vase-life of cut roses Kasetsart J. Natural Sci. 27 91 97
Kumar, N., Srivastava, G.C. & Dixit, K. 2008 Hormonal regulation of flower senescence in rose (Rosa hybrida L.) Plant Growth Regulat. 55 65 71
Lineberger, R.D. & Steponkus, P.L. 1976 Identification and localization of vascular occlusions in cut roses J. Amer. Soc. Hort. Sci. 101 246 250
Lukaszewska, A.J., Tonecki, J., Woltering, E.J. & Gorin, N. 1990 Effect of ethylene and silver thiosulfate on vase life of ‘Sonia’ roses Gartenbauwissenschaft 55 118 121
Macnish, A.J., Leonard, R.T., Borda, A.M. & Nell, T.A. 2010 Genotypic variation in the postharvest performance and ethylene sensitivity of cut rose flowers HortScience 45 790 796
Marousky, F.J. 1969 Vascular blockage, water absorption, stomatal opening, and respiration of cut ‘Better Times’ roses treated with 8-hydroxyquinoline citrate and sucrose J. Amer. Soc. Hort. Sci. 94 223 226
Marousky, F.J. 1971 Inhibition of vascular blockage and increased moisture retention in cut roses induced by pH, 8-hydroxyquinoline citrate, and sucrose J. Amer. Soc. Hort. Sci. 96 38 41
Mayak, S. & Halevy, A.H. 1972 Interrelationships of ethylene and abscisic acid in the control of rose petal senescence Plant Physiol. 50 341 346
Mor, Y., Johnson, F. & Faragher, J.D. 1989 Preserving the quality of cold-stored rose flowers with ethylene antagonists HortScience 24 640 641
Nell, T.A. & Leonard, R.T. 2004 Identifying long-lasting cut rose varieties. Amer. Floral Endowment Spec. Res. Rpt. No. 416
Nijsse, J., van der Heijden, G.W., van Ieperen, W., Keijzer, C.J. & van Meeteren, U. 2001 Xylem hydraulic conductivity related to conduit dimensions along chrysanthemum stems J. Expt. Bot. 52 319 327
Ohkawa, K., Kasahara, Y. & Suh, J. 1999 Mobility and effects on vase life of silver-containing compounds in cut rose flowers HortScience 34 112 113
Philosoph-Hadas, S., Golan, O., Rosenberger, I., Salim, S., Kochanek, B. & Meir, S. 2005 Efficiency of 1-MCP in neutralizing ethylene effects in cut flowers and potted plants following simultaneous or sequential application Acta Hort. 669 321 328
Reid, M.S., Mokhtari, M., Lieth, J.H., van Doorn, W.G. & Evans, R.Y. 1996 Modelling the postharvest life of cut roses Acta Hort. 424 137 144
RueySong, L., MeiLian, S. & SueFen, L. 2001 Effect of exogenous ethylene and ethylene inhibitor on flower physiology of cut rose ‘Grand Gala’ and ‘Golden Medal’ J. Chinese Soc. Hort. Sci. 47 281 290
Staby, G.L., Basel, R.M., Reid, M.S. & Dodge, L.L. 1993 Efficacies of commercial anti- ethylene products for fresh cut flowers HortTechnology 3 199 202
Twumasi, P., van Ieperen, W., Woltering, E.J., Emons, A.M.C., Schel, J.H.N., Snel, J.F.H., van Meeteren, U. & van Marwijk, D. 2005 Effects of water stress during growth on xylem anatomy, xylem functioning, and vase life in three Zinnia elegans cultivars Acta Hort. 669 303 311
van Doorn, W.G. 1990 Hydroxyquinoline citrate and low pH prevent vascular blockage in stems of cut rose flowers by reducing the number of bacteria J. Amer. Soc. Hort. Sci. 115 979 981
van Doorn, W.G., de Witte, Y. & Perik, R.R.J. 1989 Effect of antimicrobial compounds on the number of bacteria in stems of cut rose flowers J. Appl. Bacteriol. 68 117 122
van Doorn, W.G. & Reid, M.S. 1995 Vascular occlusion in stems of cut rose flowers exposed to air: Role of xylem anatomy and rates of transpiration Physiol. Plant. 93 624 629
Xue, J., Li, Y., Tan, H., Yang, F., Ma, N. & Gao, J. 2008 Expression of ethylene biosynthetic and receptor genes in rose floral tissues during ethylene-enhanced flower opening J. Expt. Bot. 59 2161 2169