RESPIRATION AND ETHYLENE PRODUCTION BY HARVESTED GREVILLEA 'SYLVIA' FLOWERS AND INFLORESCENCES

Abstract

Respiration and ethylene production by Grevillea 'Sylvia' flowers and inflorescences were measured to characterise the postharvest senescence processes of this new cut flower crop. The respiration rate on day 0 (harvest) of flowers at sequential development stages decreased to a minimum in the fully developed flower, and then increased after the perianth was shed. In contrast, ethylene production increased at an intermediate development stage, during perianth abscission and senescence. Respiration and ethylene production rates both decreased by day 1 after harvest. Accordingly, the respiration and ethylene production trends across development stages which were evident on day 0 were greatly attenuated on days 1, 2 and 3. Respiration rate for whole inflorescences declined rapidly within 6 h of harvest to a comparatively steady state level. Provision of sugar in the vase solution maintained respiration at a higher steady state level. Ethylene production by whole inflorescences tended to rise progressively from harvest until the studies were terminated.