Recommendations for Maintaining Postharvest Quality
Michael S. Reid and Linda Dodge
Department of Environmental Horticulture, University of California, Davis, CA 95616
In the last twenty years, the flowers of various commercial hybrids of species of the genus Alstroemeria, variously calledAlstroemeria, Peruvian Lily, or Lily of the Incas, have become an increasingly important part of the commercial cut flower trade. The flowers come in a variety of types and colors. All have a long postharvest life, typically terminated by petal drop and/or yellowing of the leaves.
For long-distance markets, flowers are harvested when the buds are about to open and start to color. For local market, harvest is delayed until the first 3 flowers have opened.
Flowers are pulled off or cut, depending on the variety. Where pulling may damage the underground parts of the plant (as in young plants of `Regina’), the stem should be cut. If flowers are cut, the remaining stem should be removed later.
Grading & Bunching
There are no official grade standards for alstroemeria, but in addition to the common characters of freedom from damage, and stem length, strength and straightness, it is suggested that the flowers in a bunch should be uniform. The flower head should be symmetrical, and the leaves should be bright green. The minimum acceptable number of florets per stem varies with cultivar but is typically 7 to 10.
Untreated alstroemeria have a long vase life; petal drop can be delayed by a 1 oz/gal(6g/L) pretreatment with silver thiosulfate (STS) for 1 hour at room temperature, followed by overnight storage in the cool-room. There is some evidence that leaf yellowing can be delayed by a combined pretreatment with two growth regulators, cytokinin and gibberellin, but this treatment is not yet commercially used in the U.S.A.
Short-term storage should be at 1-2°C (34-36 oF) in good-quality water. For long-term storage, the flowers should be cooled, then wrapped in newsprint and polyethylene and maintained at 1-2°C for two to three weeks.
Ethylene causes early loss of flower petals, and STS treatment (above) is helpful in extending the natural life of the harvested flowers.
Rates of Respiration
Remain to be determined.
Response to CA
Our data show no deleterious effects of controlled atmospheres, although flowers were destroyed in anoxic conditions.
Freezing may occur at temperatures below –0.5°C (31°F). Symptoms include water-soaking and collapse of leaves and petals.
Postharvest Technology Research and Information Center
Department of Pomology
University of California
One Shields Ave., Davis, CA 95616-8683
Send comments and questions to Postharvest Technology Research and Information Center
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Produce/ProduceFacts/Veg/alstro.html updated July 12, 2000