Extending Cut Paeonia Lactiflora Pall. Storage Duration Using Sub-Zero Storage Temperatures

Cut peonies (Paeonia lactiflora Pall.) have a relatively short vase life and limited availability due to seasonal production. Cultivars Festiva Maxima (FM), Monsieur Jules Elie (MJE), and Sarah Bernhardt (SB) stored at 0.7 °C had a longer flower open time at 12 weeks of storage compared to those held at −3.1 or 3.5 °C, while the flower bud time was unaffected. The flower open time of FM and MJE was no different for stems stored at a sub-zero temperature of −0.6 °C for 16 weeks compared to non-stored stems. Flower quality, opening, and lack of deformity was reduced at 16 weeks of storage in comparison to non-stored flowers, but higher for stems stored at −0.6 °C compared to 0.7 °C. Pre-treating stems before storage with pulses of a commercial hydrator solution or a 200 g·L−1 sucrose solution for 2 h at 4 °C had little commercial significance compared to non-pulsed control stems. The total phenolic content, malondialdehyde, and superoxide dismutase were not effective indicators of open time or quality loss. This study is the first to demonstrate the successful use of a non-freezing, sub-zero storage temperature for peony, and the first to store cut peonies for 16 weeks, despite an increased risk of reduced flower quality.