Studies on the characteristics of recommended soybean varieties in Korea 1. on the days from planting to blooming and from blooming to ripening:

한국의 대두장려품종의 특성에 관한 연구 1. 개화일수와 결실일수

10 of Korean domestic recommended varieties(all of them are determinate type) and 10 of introduced varieties from U.S.A.(All of them are indeterminate type) are grown in replicated field in order to clarify the varietal differences in the days from planting to blooming to ripening. The results are summarized as follows; 1. Domestic varieties showed remarkable shortday sensibility for the days from planting to blooming. The difference in sensibility between domestic and introduced was significant while within the domestic group the differences were not significant. 2. The days from planting to blooming were linearly shortened in accordance with the delayed planting from the late April through the late June. 3. Annual variation in days from planting to blooming was not noticeable in the domestic varieties while the introduced ones showed remarkably. 4. The days from blooming to ripening were significantly shortened for the introduced varieties but not significantly for the domestic varieties accordingly with the delayed planting. The mean shortest days of domestic varieties were longer than the mean shortest days of introduced varieties. 5. The days from planting to blooming was shortest when a variety was grown during early August through middle September (with 12.5~13.5 hrs day length and 22~$27^{\circ}C$ temperature), and the days from blooming to ripening were also shortest when a variety was matured within same duration. These were true for the varieties of both groups.

대두 한국장려품종 10 개품종과 도입된 무한신육성 10개품종을 4월 15일부터 7월 29일까지 15일간격으로 파종하고 개화일수 및 결실일수를 조사하여 품종별, 파종기별로 이 2가지 특성의 변이들 분석하였다. 그 결과를 요약하면 다음과 같다. 1. 파종기가 늦어짐에 따른 장려품종의 개화일수단축율은 도입종보다 현저하게 컸다. 2. 4월말에서 6월말까지에는 파종기가 늦어짐에 따라 개화일수는 직선적으로 단축되었는데 장려품종간의 차는 비교적 적었고 도입종과의 차는 컸다. 3. 개화일수의 년간변이는 장려품종들은 극히 적고 도입종들은 매우 컸다. 4. 결실일수도 파종기가 늦어짐에 따라 단축되는데 단축율은 도입종에 비하여 장려품종이 현저하게 적으며 최단결실일수는 도입종이 짧았다. 5. 장려품종과 도입품종이모두 8월상순~9월중순(일장 12.5~13.5시간, 온도 22~$27^{\circ}C$)에 생장된 것이 개화일수가 가장 짧았고 이 기간에 결실된 것이 결실일수도 가장 짧았다.