International Journal of Plant & Soil Science

There is a shortage of herbaceous peony cut flowers in the world market in late winter/early spring. The quality of these prestige flowers, when cultivated in warm climate regions and stored in cooling chambers during dormancy, is influenced by pre-dormancy, dormancy, and post dormancy conditions. In this article, various regimes of peony dormancy with constant and variable temperatures were studied. Containers with plants of cv. ‘Sarah Bernhardt’ were exposed to a pre-dormancy temperature of 15°C and, after two weeks, transferred to cooling chambers in order to keep dormancy under four constant or diurnal temperature regimes. On three different dates, plants from each treatment were transferred to a greenhouse for release from dormancy and the beginning of sprouting. During commercial harvest, data on height and thickness of flower stems, number of harvested flowers per plant, and dates of harvested flowers were collected. Using these data, the index of market quality of peony flowers was defined and regressed on dummy variables that reflected chilling regimes and dormancy duration. Statistically significant differences in market quality were shown between the treatments with the lower storage temperatures 20 C, 2-100 C, and 2-150 C, and the reference treatment with a storage temperature of 2 – 200 C. Statistically significant differences were also shown between the treatments with the shorter storage period of 6 weeks, 4 days or of 8 weeks, on the one hand, and the reference treatment with the storage of 9 weeks, 3 days, on the other. Close results were obtained for the treatments with the constant temperature of 20 C and with the diurnal alternating temperature of 2-100C. Therefore, growers can expect economic gains from saving energy during dormancy under a suitable temperature regime.