QUALITY IMPROVEMENT OF HYDROPONICALLY GROWN LEAF VEGETABLES
Effect of the concentration of the nutrient solution on the nutritional quality of lettuce and Japanese honewort was investigated. Ascorbic acid, sugars and nitrate contents were analyzed for quality evaluation of the vegetables. In plants grown in ¼ strength standard nutrient solution, the growth was unsatisfactory although the ascorbic acid and sugar contents were higher while the nitrate content was lower. Therefore, the concentration of the nutrient solution was changed and the plants were transferred to a markedly diluted solution for 2 to 7 days before harvest. As a result, it became possible to harvest plants with high ascorbic acid and sugar contents and a low nitrate content. It was considered that these techniques could be easily applied to hydroponically grown leaf vegetables.
Shinohara, Y. and Suzuki, Y. (1988). QUALITY IMPROVEMENT OF HYDROPONICALLY GROWN LEAF VEGETABLES. Acta Hortic. 230, 279-286