ＮＦＴ栽培におけるイチゴの養水分吸収に及ぼすＣＯ２施用の影響

Abstract

This experiment was carried out to investigate the effects of CO2 enrichment (700-800 ppm in the day time) on the absorption of water and mineral nutrients in strawberry (Fragaria × ananassa Duch. cv. Nyoho) grown by nutrient film technique. The concentration of major elements in the nutrient solution were NO3- : 5, NH4+ : 1, H2PO4- : 1, K+ : 3, Ca2+ : 1, Mg2+: 1 mmol·L-1. Vigorous growth and high yield were obtained by CO2 enrichment. In control (ambient CO2, 200-400 ppm), the uptake concentration (each mineral absorbed per unit volume of water absorbed, n/w) was almost equal to the concentration of the solution, throughout growing period. However, under CO2 enriched condition, n/w and total uptake amount of minerals increased by 30-60% compared to control, especially, from November to February when the temperature and light intensity were low. The n/w of minerals were also 50-100% higher than the concentration of the nutrient solution. Total-N concentration in leaves was markedly decreased by CO2 enrichment, while there was little difference in P, K, Ca and Mg. To keep the concentration of nutrients in the solution, the concentration of nutrients should be kept 50-100% higher than those previously reported, when strawberry plants are grown with CO2 enrichment.