Effects of CO2 enrichment on yields and preservability of cut flowers in Phalaenopsis

Abstract

The effect of CO2 enrichment on Phalaenopsis cut flower production was examined for 30 months throughout five flowering cycles. The plant was cultured in three greenhouses with different CO2 levels of (A): control, daily mean of ambient air=438 ppm; (B): 700 ppm; and (C): 1000 ppm. 1. The fresh weight of cut flowers, the numbers of inflorescence and flowers per 20 plants varied, depending on the CO2 concentration for each flowering cycle. 2. The preservability (vase life) of cut flowers always improved under higher CO2 levels. Organic acid contents of plants were also higher under higher CO2 levels. The malic acid content in the flowers was higher than in the younger leaf and flower stalk at 1:00 PM and 10:00 PM; and it was also higher in the younger leaf than in the flower stalk at 10:00 PM, but lower at 1:00 PM. The pH value of plants was always lower, at higher ambient CO2 levels, and lower in the younger leaf and flower stalk at 1:00 PM than at 10:00 PM, whereas at those same times the sugar content at the higher ambient CO2 levels reached its maximum.