Wednesday, August 1, 2012
Grand Ballroom
Postharvest quality (vase life or longevity) of cut flowers is one of the most important characteristics that determine consumer preference and satisfaction. Both ethylene sensitivity and microbial contamination play important roles in determining the vase life of cut flowers. The objective of this study was to evaluate the effect of 1-MCP and antimicrobial agents on postharvest quality of cut flowers with different levels of ethylene sensitivity. Flower stalks of rose (Rosa hybrida), gerbera (Gerbera jamesonii H.), carnation (Dianthus caryophyllus), and snapdragon (Antirrhinum majus) were obtained from a local commercial grower. Flower stems were trimmed to a length of 30–45 cm and placed vertically in a 250-ml flower bag containing sterilized water. Cut flowers were divided into two groups. One group was exposed to 0.9 µL·L-1 1-MCP (0.14%, Rohm Hass) in sealed stainless steel containers at 20 °C for 16 h. The control group was held at 20 °C for 16 h without any 1-MCP treatment. Flowers were placed under controlled environmental conditions (relative humidity 60% to 75%, temperature 20 °C and dark) for 14 days. Quality measurements including water uptake, color, abscission and wilting, digital images and microbial populations of totals plate counts, as well as mold and yeast counts in vase water were conducted on d0, d1, d7, and d14. Measurement of chlorophyll fluorescence (CF) on the flower sepal as a physiological tool was also conducted. Treatment of 1-MCP significantly delayed the senescence of cut flowers, reduced wilting and abscission, especially for ‘carnation’, ‘rose’ and ‘gerbera’, while it had limited effect on snapdragons. Decrease of CF was also significantly delayed by 1-MCP treatment. Antimicrobial agents showed potential to reduce microbial population in stalk solution. However, no interaction between antimicrobial agents and 1-MCP was found. Changes in CF showed significant relationship to senescence of cut flowers. CF is an important quality parameter and should be incorporated in the postharvest quality evaluation of cut flowers.