499 Postharvest Care and Handling Practices for Cut Poinsettia cv. `Winter Rose Dark Red'

Abstract

<jats:p>The traditional use of poinsettias has been as potted plants. A new poinsettia variety, `Winter Rose Dark Red', is performing well as a cut flower, lasting 2 to 3 weeks. Various postharvest handling procedures were examined, including stem processing methods at harvest, storage and transit conditions, as well as handling practices at the wholesale, retail, and consumer levels, to determine the best handling practices to maximize quality and longevity. At harvest, traditional latex controlling techniques, such as dipping stems in 95% ethanol for 10 min and burning or boiling stem tips were tested. Stems wilted faster when dipped in ethanol or burned. The woody nature of the stem contains little latex compared to traditional varieties; thus, no latex-controlling methods are needed or beneficial. After harvest, there was no benefit found in hydrating stems in a commercial hydration solution compared to plain water. Transport and/or storage conditions between 10 to 15 °C for 3 to 4 days maximized longevity. Chilling injury occurred when transported at 4 °C. Leaves and bracts wilted when stored dry in a box, but recovered within 12 to 24 h when stored for 2 days. Leaves abscised after exposure to short-term wilting but no bract abscission occurred. Storing stems in a 10% bleach solution prevented wilting and reduced bacterial growth. Bracts were sensitive to mechanical injury during transit, resulting in bruising lesions on the bracts, which increased sensitivity to bract edge burn. Stems declined faster when maintained in a floral preservative compared to water during the consumer phase.</jats:p>

Optimizing Postharvest Life of Cut `Renaissance Red' Poinsettias

“…Floral solution heated to 38 or 100 °C (10 min) had no effect on vase life or days to fi rst cyathium abscission. Leonard et al (2000) also noted that 100 °C water dips had no effect. In contrast, a 24-h pulse of 10% sucrose reduced vase life and resulted in the earliest cyathium abscission (13.0 d).…”

“…The stem ends of 'Renaissance Red' poinsettias were quite woody and produced little latex when harvested. Leonard et al (2000) concurred, noting that cut 'Winter Rose Dark Red' stems produced little latex and that 10-min 95% ethanol dips caused faster wilting. In contrast, Gordon et al (1986) found that 10-min dips in isopropyl alcohol applied immediately or within 1 h after harvest increased the time to 50% cyathium abscission in cut 'Annette Hegg Diva' and 'Annette Hegg Topwhite' poinsettias by 3 d. However, whereas Gordon et al (1986) defi ned vase life as days to 50% cyathium abscission, we differentiated between cyathium abscission and termination of vase life.…”

“…In a preliminary experiment cut poinsettia stems showed extensive cold damage when stored at 4 °C for 1 week (data unpublished). Leonard et al (2000) also noted that chilling injury occurred when cut stems were transported at 4 °C. Staby et al (1978) recommended a minimum storage temperature of 10 °C for potted poinsettias to avoid chilling injury.…”

“…2b), whereas dry storage caused the most rapid leaf abscission (Fig 2c). Leonard et al (2000) stated that leaves and bracts of cut poinsettias dry stored for 2 d rehydrated within 12 to 24 h but leaf abscission occurred.…”

“…Limited research, however, has examined the postharvest life of cut poinsettia fl owers (Gordon et al, 1986;Leonard et al, 2000). Poinsettias produce a milky latex when cut and several pretreatments have been proposed to eliminate potential stem-plugging from the latex, including dipping the stem ends in alcohol or boiling water and heat searing.…”