Abstract
These experiments were carried out in order to examine the effect of intermittent solution supply on improvement of quality of spinach plants cultivated in solution culture. Intermittent solution supply was practiced at the cycles of 15 min on and 120 min off (15-120 regime), 60 min on and 120 min off (60-120 regime) for 6 days. The results obtained were as follows: 1) Plant growth was little affected by treatment of intermittent solution supply. 2) Ascorbic acid content of spinach increased with the 15-120 regime after 3 days, but after 6 days, this difference when compared to that of continuous supply (control) disappeared. Sugar content of the 15-120 regime increased to 60% of that of control after 6 days. On the other had, nitrate content of the 15-120 regime was reduced to 66% of that of control after 3 days. But soluble oxalate content showed no changes by this treatment. 3) The above results suggests that improvement of the quality of spinach plants can be expected by treatment with intermittent solution supply.
