PRODUCTION AND POSTHARVEST CHARACTERISTICS OF ROSA-HYBRIDA L MEIJIKATAR GROWN IN POTS UNDER CARBON-DIOXIDE ENRICHMENT

The effects of carbon dioxide enrichment on growth, photosynthesis, an d postharvest characteristics of 'Meijikatar' potted roses were determ ined. Plants were grown in 350, 700, or 1050 mul CO2/liter until they reached 50% flower bud coloration and then were placed into dark stora ge for 5 days at 4 or 16C. Plants grown in 700 or 1050 mul CO2/liter r eached the harvest stage earlier and were taller at harvest than plant s produced in 350 mul CO2/liter, but there were no differences in the number of flowers and flower buds per plant among CO2 treatments. Plan ts grown in early spring were taller and had more flowers and flower b uds than plants grown in late winter. Shoot and root growth of plants grown in 700 or 1050 mul CO2/liter were higher than in plants produced in 350 mul CO2/liter, with plants grown in early spring showing great er increases than plants grown in late winter. Immediately after stora ge, plants grown in 350 mul CO2/liter and stored at 4C had the fewest etiolated shoots, while plants grown in 1050 mul CO2/liter and stored at 16C had the most. Five days after removal from storage, chlorophyll concentration of upper and lower leaves had been reduced by almost-eq ual-to 50% from the day of harvest. Carbon dioxide enrichment had no e ffect on postharvest leaf chlorosis, but plants grown in early spring and stored at 16C had the most leaf chlorosis while plants grown in la te winter and stored at 4C had the least leaf chlorosis.