SHORT TERM APPLICATIONS OF LOW AND HIGH TEMPERATURE STRESSES TO ROOTS FOR HIGH QUALITY SPINACH (SPINACIA OLERACEA L.)
Low temperature stress to roots causes a depression in root water absorption, and the resulting water deficit can induce the plant adaptive functions such as osmo-regulation and antioxidation. Therefore, plant responses to the root low temperature stress can be expected to produce high quality vegetables with the higher concentra-tions of the healthful substances such as sugars and antioxidants and with the lower concentrations of the harmful substances such as NO3- and oxalic acid. Two weeks treatment with the root low temperature stress of 10°C produced high quality spinach with the higher concentrations of sugar, ascorbic acid and Fe, and with the lower concentrations of NO3- and oxalic acid, whereas the longer stress treatment resulted in extremely depressed plant growth. Therefore the short term application of the low temperature stress combined with the short term pre-treatment with the high temperature of 30°C was examined, when the high temperature pre-treatment enhanced favorable effects of the short term low temperature stress. During ten days before the harvest, the high temperature pre-treatment of 30°C was applied for one day or three days, and following the high temperature pre-treatment, the low temperature stress of 10°C was applied for four days or seven days. The three days high temperature pre-treatment followed by the seven days low temperature stress brought the highest quality with a slight depression in growth. This suggests that the short-term application of the low temperature stress to roots after the short-term high temperature pre-treatment is applicable for value-added leafy vegetables.
Chadirin, Y., Nakano, A., Kagawa, H., Sago , Y. and Kitano, M. (2012). SHORT TERM APPLICATIONS OF LOW AND HIGH TEMPERATURE STRESSES TO ROOTS FOR HIGH QUALITY SPINACH (SPINACIA OLERACEA L.). Acta Hortic. 932, 351-358
low and high temperature stress, short term application, spinach