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Kristian Borch and Lars Hoyer

Stressing miniature roses during transport can reduce their appearance and keeping quality. Factors that stress plants during transport are: storage in darkness, fluctuating temperatures, exposure to ethylene, high humidity, and mechanical damage. The post-production keeping quality of three cultivars of Parade® miniature potted roses (Rosa × hybrida) from three growers in Denmark were evaluated during winter and summer 1994, using three levels of simulated transport (ST) for 0, 2, or 4 days. The main causes of decreased keeping quality were wilting of flowers, infection by botrytis, and an increased number of yellow buds. After 18 days, there was no difference in the percentage of wilted flowers between 0 and 2 days of ST for all cultivars. However, for two of the three cultivars exposed to 4 days of ST the percentage of wilted flowers increased, while there was no significant effect from the ST on the percentage of wilted flowers. The degree of wilting was also dependent on origin of the plants and was less severe in summer than in winter. The number of yellow buds and infection by botrytis increased in plants exposed to 4 days of ST, and was more pronounced in winter. We conclude that, if the initial quality of the miniature potted rose is good, and the stress conditions during transport are controlled, damage can be kept at a minimum level.

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Ria T. Leonard, Terril A. Nell, Lars Hoyer, Jim E. Barrett, and David G. Clark

Postproduction evaluation trials have been developed in North America and Europe to test postproduction performance of potted roses from individual growers. The results of the trials have been compiled on the “Roses On The Web” Website ( Roses on the WEB is a cooperative project between Poulsen Roses ApS, Denmark, the Danish Institute of Agricultural Sciences, and the Univ. of Florida. The goal of the Website is to provide growers participating in the evaluation trials a quick and easy way to obtain results on the postproduction quality of their roses. Plants receive 4 days of simulated transport, sleeved in a box in darkness at 16 °C. After transport, plants are maintained at 20 °C at 8 μmol·m–2·s–1 for 12 hours/daily. Relative humidity is maintained at 55% ± 5%. To determine quality, several parameters are recorded at day 0 (day of arrival), 11, 18, 22, and 28. The recordings include the number of open and damaged flowers and buds, percentage of damaged leaves, and the presence of disease and pests. Based on the results of all the measurements, each plant is given a postproduction rating or index, indicating quality. Results from each trial are tabulated and stored on the Website. Growers are able to view their results by entering a password. Growers can evaluate their quality over time and are also able to compare their quality with other growers. Many quality problems are manifested in the postproduction environment and can often be directly related to incorrect greenhouse conditions and/or cultural practices. “Roses On The Web” is a tool that provides quick, up-to-date information that can be crucial to the success of a grower. Differences in quality were found based on grower, time of year and variety.