Decreasing the NO3 and increasing the vitamin C contents in spinach by a nitrogen deprivation method.
Excessive use of nitrogen fertilizers is known to increase the NO3 and reduce the vitamin C contents in fruits and vegetables. We investigated the concentration of these compounds in spinach leaves when plants were transferred to nitrogen-free media prior to their harvest. It was noted that a pre-harvest transfer of spinach to N-free media reduces the NO3 and increases the vitamin C content of the leaves by a substantial amount in a 2-3 day period. It is suggested that this technique may be suited to produce spinach or other leafy vegetables with low NO3 and high vitamin C contents under commercial hydroponic conditions.
Mozafar
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Division of Agronomy, Institute of Plant, Sciences, Swiss Federal Institute of Technology, ETH-Zentrum, Zürich, Switzerland.
D001205:Ascorbic Acid / Q000032:analysis*; D005308:Fertilizers; D009566:Nitrates / Q000008:administration & dosage / Q000032:analysis*; D009584:Nitrogen / Q000008:administration & dosage*; D018724:Spinacia oleracea / Q000737:chemistry* / Q000254:growth & development
D005308:Fertilizers; D009566:Nitrates; D009584:Nitrogen; D001205:Ascorbic Acid; C006568:ammonium nitrate