Abstract
The effects of light intensity and temperature on the L-ascorbic acid concentration of Spinacea oleracea L. cv. Vilofley were observed. The experiment carried out in autumn 1982. The spinach planted in experimental planters divided into three groups as in the followings. A: unshaded (control, relative illuminance 100%), B: shaded (relative illuminance 25-32%), C: shaded and heated (vinyl house, relative illuminance 25-32% and high temperature).
The results obtained summarized as follows:
1) Under shading without heating, the plant growth rate decreased, on the other hand, shading together with heating gave the thin leaves notwithstanding their rapid growth.
2) The falls in L-ascorbic acid concentration by shading were observed both on fresh and dry matter. However, the additional decline of L-ascorbic acid under shaded and heated condition was found only in the values of dry matter.
3) A significant positive correlation was found between L-ascorbic acid concentration and chlorophyll content of leaf blade.
4) As a conclusion, it was confirmed that spinach planted in venyl house grew rapidly and had a good shape, but L-ascorbic acid content of the plant decreased considerably compared with spinach planted in the open field, both in the values of fresh and dry matter.
