窒素栄養条件がキャベツのビタミンU含有率に及ぼす影響(収穫後の貯蔵・流通)  [in Japanese] Effects of Nitrogen Fertilization and Cropping Season on the Vitamin U Concentration in Cabbage(Postharvest Physiology & Technology)  [in Japanese]

現地で採取したキャベツのビタミンU含有率は最低値7.0mg・kg^<-1>〜最高値66.2mg・kg^<-1>の範囲に分布し,平均値は28.9mg・kg^<-1>であった.各作期別のビタミンU含有率は7月収穫で最も高く,次いで8月,9月,10月収穫の順で低かった.ビタミンU含有率は窒素の低栄養条件下で低く,窒素施用量の増加に伴って高まった.また,ビタミンU含有率は緩効性の有機質肥料よりも速効性の有機質肥料の施用で高まった.さらに,ビタミンU含有率は夏どり作型で高く秋どり作型で低い傾向にあった.また,窒素供給能の高い栽培圃場でビタミンU含有率は高かった.

Vitamin U (VU) concentration in cabbages harvested in Hokkaido ranged from 7.0 - 66.2 mg kg^<-1>, and the mean was 28.9 mg kg^<-1>(1996-1998, n=92). Among cropping seasons, the mean VU concentration in cabbages was highest in July (40.6 mg kg^<-1>), then declined gradually until October (13.2 mg kg^<-1>). VU concentration in cabbages increased with increases in applied nitrogen (N) fertilizer, or growth in fields with higher N fertility, and in summer cropping rather than autumn cropping. In the case of cabbbage production using organic matter to reduce usage of chemical fertilizer, the VU concentration in cabbage grown with fish meal (fast- N- release) was higher than that growth with rice bran (slow-N-release). These results indicate that changes in VU concentration in cabbages depend on N nutritional condition.