Hormone Sprays and Supplemental Light Prevent Cold-storage-induced Postharvest Leaf Chlorosis and Abscission in `Stargazer' Hybrid Lilies

Abstract

Rapid leaf chlorosis and abscission limits the use of cold storage for post-production short-term holding of potted lilies. We investigated the effects of storage temperature, storage irradiance and pre-storage foliar sprays of gibberellin and/or cytokinin on postharvest leaf and flower quality of Lilium sp. `Stargazer' hybrid lilies. Storage of “puffy bud” stage plants at 4, 7, or 10 °C in dark for 2 weeks induced leaf chlorosis within 4 days in a simulated consumer environment, and resulted in 60% leaf chlorosis and 40% leaf abscission by 20 days. Cold-storage also reduced the duration of flower bud opening, inflorescence and flower longevity, and increased flower bud abortion. Providing light up to 40 μmol·m–2·s–1 during cold-storage at 4 °C significantly delayed leaf chlorosis and abscission and increased the duration of flower bud opening, inflorescence and flower longevity. Foliar sprays of ProVide (100 mg·L–1 GA4+7) and Promalin [100 mg·L–1 GA4+7 and 100 mg·L–1 benzyladenine (BA)] effectively prevented leaf chlorosis and abscission at 4 °C, while ProGibb (100 mg·L–1 GA3) and ABG-3062 (100 mg·L–1BA) were not effective. Accel (10 mg·L–1 GA4+7 and 100 mg·L–1 BA) showed intermediate effects on leaf chlorosis. Flower longevity was increased and bud abortion was prevented by all hormone formulations except ProGibb. The combination of light (40 μmol·m–2·s–1) and Promalin (100 mg·L–1 GA4+7 and 100 mg·L–1 BA) completely prevented cold-storage induced leaf chlorosis and abscission and significantly improved flower opening and overall plant quality.