Effects of K and Ca on growth and oxalate and nitrate concentrations in water-cultured spinach (Agriculture)

ホウレンソウをK及びCa濃度の異なる培養液で水耕栽培し, 葉内シュウ酸濃度, 葉内硝酸濃度, 葉内無機成分濃度を測定した。K及びCaの増施により, 葉内シュウ酸濃度が減少し, 葉内硝酸濃度が増加した。一方, K及びCaの増施により, 葉内Mg濃度が低下した。Kの増施により葉内Ca濃度が, Caの増施により葉内K濃度が減少した。葉内Mg濃度と葉内シュウ酸濃度との間に正の相関, 葉内硝酸濃度との間に負の相関がみられた。K, Ca及びMgの吸収の間に拮抗関係がみられ, そのバランスで, 葉内硝酸濃度及び葉内シュウ酸濃度が変化するものと思われた。葉内シュウ酸濃度と葉内硝酸濃度との間に負の相関がみられ, 培養液中のK及びCaの組成を変化させて, 葉内シュウ酸ならびに硝酸濃度を同時に低下させることは困難であると思われた。Spinach was grown in nuitrient solutions containing 2,4,6,8,10 and 12 me/l of K and 2,4 and 8 of Ca, respectively. Growth and concentrations of oxalate, nitrate, K, Ca and Mg in leaves were determined. High concentrations of K and Ca in nutrient solution decreased concentrations of oxalate and Mg in leaves and increased nitrate concentration. Negative correlation between oxalate and Mg concentrations in leaves was found. Competitive relations among uptake of K, Ca and Mg were recognized. This competitive status probably affected concentrations of oxalate and nitate in leaves. Negative correlation be tween concentrations of oxalate and nitrate in leaves were recognized. It was concluded difficult to decrease concentrations of both oxalate and nitrate in leaves by modification of K and Ca concentrations in nutrient solution.departmental bulletin pape