Effect of postharvest hot water dipping on quality and vase life of cut chrysanthemums

摘要

Postharvest hot water dipping (HD) treatment of cut chrysanthemum stems has been commonly used by flower growers in Korea Republic. However, no scientific information as to the effect of HD treatment on the quality of cut chrysanthemum flowers is available. The objective of this experiment was to investigate the effect of HD on the quality and vase life of cut chrysanthemums (Dendranthema grandiflorum [Chrysanthemum morifolium]). The most effective treatment was dipping the stems in boiling water for 20 seconds (HD 20s) after harvest. This treatment significantly extended the vase life of cut 'Chunkwang' chrysanthemums by 1.7 times compared with the untreated flowers. HD 20s markedly increased the fresh weight, flower diameter, water uptake and water balance of cut 'Chunkwang' chrysanthemums. The HD-treated flowers showed no leaf wilting after 24 h at room temperature. Recutting of basal stems after HD and simulated shipment at 20degC for 24 h increased the vase life of cut 'Chunkwang' chrysanthemums. Delayed HD treatment within 24 h after harvest extended the vase life remarkably compared with the untreated flowers. HD treatment markedly decreased the number of bacteria of cut chrysanthemum stems. The number of bacteria of HD 20s recorded was 9.6, 34.7 and 50.5% in upper, middle and basal parts of the stems, respectively. The effect of HD on cut spray chrysanthemums had no appreciable effect on flower quality and vase life.