Abstract
This study describes the relations between cultural conditions and vitamin C contents of Japanese Honeyworts, tomatoes and cucumbers. Cultural methods were classified into four types, namely, soilless, greenhouse, blanching and normal culture.
It is recognized that the vitamin C content of vegetables grown by “soilless culture” or by “greenhouse culture” was not significantly lower than those grown by “normal culture. ”
However, in the case of green leaved Japanese Honeyworts, harvested during the winter season, the vitamin C content of those grown by “greenhouse culture” was higher than those grown by “normal culture, ” while vitamin C content in blanched Japanese Honeyworts, was extremely low.
From the comparison of vitamin C contents of vegetables harvested in winter and summer seasons, higher vitamin C contents were observed in tomatoes and cucumbers in summer and green Japanese Honeyworts, in winter regardless of cultural methods.
In these vegetables, vitamin C content of “immature crops” was rather higher than that of “mature crops. ”
