Carnations: effects of high concentrations of carbon dioxide on flower physiology and longevity

Abstract

Elevated carbon dioxide atmosphere treatments (60% carbon dioxide in air) were applied for 1 or 3 days at 0 or 20°C to cut white carnation flowers (cv. Delphi) as a potential disinfestation treatment. Water uptake, flower diameter, respiration rate, ethylene production, longevity and pH of sap expressed from petals were measured to reveal the physiological response of the carnations to the treatments. Carbon dioxide did not affect longevity at 0 or 20°C. The higher temperature was more detrimental to the flowers than was 60% carbon dioxide. High temperature induced earlier peaks in rates of respiration and ethylene production. There was a transient yellowing of the petals upon removal from the 60% carbon dioxide treatments at 20°C. The pH of extracts from these petals was about 7 compared with pH 6 of the extracts from petals that did not yellow. We conclude carnation flowers can withstand 60% carbon dioxide at 0°C without detriment to vase life, conditions that could constitute a disinfestation treatment against some insects.