2007 Volume 76 Issue 2 Pages 232-237
In recent years, the number of patients on dialysis due to kidney failure is tending to increase in Japan. These patients must restrict potassium intake, because they cannot excrete the potassium ion adequately. The objective of this study was to establish a method of cultivating spinach with a low potassium content while maintaining normal plant growth. Spinach plants were grown hydroponically with reduced potassium application throughout the growth period or with no potassium applications during the last half of the growth period. There were no significant differences in fresh weight at harvest between controls and plants in the potassium-limited treatments. The potassium content per fresh weight was reduced as much as 32% by the former treatment and 79% by the latter treatment compared with the controls. These results suggest that it is possible to produce low-potassium spinach maintaining the normal plant growth. Sodium and magnesium content increased with the decrease of potassium content, showing that they had a role in the control of osmotic pressure in the absence of normal potassium.
