Postharvest Handling of Heliconia, Red Ginger, and Bird-of-Paradise

Abstract

Heliconia (Heliconia spp.), red ginger (Alpinia purpurata), and bird-of-paradise (Strelitzia reginae) inflorescences have similar stem structures and postharvest handling regimes. Inflorescences, especially heliconia, should be harvested in the morning while still turgid, and at the most suitable stage of development which varies with the species, its proposed use, and market requirements. Treatments that extend postharvest vase life, either or both enhance water uptake or prevent water loss and provide an exogenous energy source. Use of the most suitable temperature for shipping and storage prolongs vase life. Heliconia should be shipped and stored at >10 °C (50.0 °F), red ginger >12 °C (53.6 °F), and bird-of-paradise at >8 °C (46.4 °F). Sucrose (10% w/v), citric acid [150 mg·L-1 (ppm)] and 8-hydroxyquinoline citrate (250 mg·L-1) are major chemicals used in pulsing and holding solution for bird-of-paradise. Holding solutions for red ginger are similar except 2% (w/v) sucrose is recommended. The response of heliconia inflorescences to different pulsing and holding solutions has been shown to be negligible. A 200-mg·L-1 benzyladenine spray extends the vase life of red ginger and heliconia. Hot water treatment of red ginger at 49 °C (120.2 °F) and 50 °C (122.0 °F) for 12 to 15 min extends postharvest vase life, kills most of the pests that infest red ginger, and reduces the geotropic response. The major postharvest problems are saprophytic mold on bird-of-paradise, negative geotropic response of red ginger, and insect infestation of all three flowers. There is no reported method to control the postharvest nectar and slime production on bird-of-paradise that provides a substrate for saprophytic mold growth. Dipping inflorescences in benomyl or thiobendazole (TBZ) at 200 mg·L-1 does help control postharvest mold growth in bird-of-paradise and heliconia. Compared to most temperate flowers, there is a need for greater understanding of morphological and physiological factors that limit the vase life of heliconia, red ginger and bird-of-paradise flowers.