Each year a wide variety of new cultivars and species are evaluated in the National Cut Flower Trial Programs administered by North Carolina State University and the Association of Specialty Cut Flower Growers. These new cultivars are tested at about 50 locations in the United States and Canada, providing valuable production and marketing information (Dole and Laushman, 2010; Dole et al., 2010). However, postharvest life, a key component of a successful cut flower cultivar, is not included in the trial program.
Commercially, cut stems are typically subjected to a hydrating solution and a holding solution. The purpose of a hydrator is to encourage water uptake. A commercial hydrator contains compounds to lower the pH, as water with a low pH is more easily taken up by stems when compared with water of high pH (Gast, 2000; Regan and Dole, 2010). Hydrators do not include sugar and are not designed to be used for extended periods of time longer than 24 h (Armitage and Laushman, 2003; Halevy and Mayak, 1981). However, a holding preservative is intended to be used for extended periods of time, 24 h or longer, typically during transport and storage. They regularly contain a carbohydrate source, an antimicrobial agent, and an acidifying agent (Dole and Wilkins, 2005; Halevy and Mayak, 1981). The carbohydrates support the cut stem, the antimicrobial agent deters the growth of stem-plugging microbes, and the acidifying agent helps slow microbial growth and encourages water uptake. Holding preservatives with a high percentage of carbohydrates aid in the opening of buds and in the development of flowers (Armitage and Laushman, 2003; Halevy and Mayak, 1981). In some cases, unamended water may be used in place of hydrator or holding solutions. The objective of this multi-year study was to identify patterns of postharvest responses to commercial hydrator and holding floral preservatives among 121 cultivars from 47 genera.
Chain of Life Network 2010 Floral crop database 12 Sept. 2010 <http://www.chainoflifenetwork.org/moa/dbs/floral_crops/default.cfm>.
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Dole, J.M., Viloria, Z., Fanelli, F.L. & Fonteno, W. 2009 Postharvest evaluation of cut dahlia, linaria, lupine, poppy, rudbeckia, trachelium and zinnia HortTechnology 19 593 600
Halevy, A.H. & Mayak, S. 1981 Senescence and postharvest physiology of cut flowers. Part 2 Hort. Rev. (Amer. Soc. Hort. Sci.) 3 59 143
Han, S.S. 1998 Postharvest handling of cut Heuchera sanguinea Engelm. flowers: Effects of sucrose and silver thiosulfate HortScience 33 731 733
Regan, E.M. & Dole, J.M. 2010 Determining optimum pH and EC levels for extended vase life of cut Rosa ‘Freedom’, ‘Charlotte’, and ‘Classy’ Acta Hort. 870 263 271