INTERACTIONS OF FLOWER STAGE, CULTIVAR, AND SHIPPING TEMPERATURE AND DURATION AFFECT POT ROSE PERFORMANCE

Simulated shipping (storage) experiments were conducted to determine t he effects of shipping temperature and duration on flower longevity an d leaf abscission of pot rose Rosa L. 'Meijikatar' (= Orange Sunblaze) and 'Meirutral' (= Red Sunblaze), In addition, three flower stages (1 = tight bud, calyx not reflexing; 2 = showing color, calyx reflexing, no petals reflexed; 3 = full color, petals beginning to reflex, tradi tional bud stage) were selected immediately prior to storing plants at 4, 16, or 28 degrees C for 2, 4, or 6 days. The experiment was conduc ted during the summer and repeated during the winter. Evaluations were made in an interior environment at 21 degrees C for both experiments. 'Meirutral' exhibited longer poststorage longevity and less leaf absc ission than 'Meijikatar' in both experiments. Flowers of both cultivar s advanced by about one stage during storage at temperatures greater t han 4 degrees C in summer, but developed more slowly in winter. Result s from both experiments showed that plants stored at 4 degrees C had t he longest poststorage floral longevity, the best flower quality, and the least leaf abscission, regardless of cultivar, storage duration, o r flower stage at the beginning of storage. For plants stored at 16 de grees C, floral longevity decreased and leaf abscission increased when the duration was longer than 4 days. At 28 degrees C, flower longevit y decreased and leaf abscission increased, especially at durations lon ger than 2 days. In the winter experiment, there was no leaf abscissio n on plants placed in the dark at 21 degrees C and watered during stor age treatments lasting up to 6 days. In the summer experiment, the you nger the flower, the more it was negatively affected by high storage t emperature. Overall, poststorage floral longevity was longer in the su mmer than the winter experiment.