Abstract
1. 20 varieties of soybean were sown in green house and field of Tokyo Agricaltural Experiment Station. Sowing times were May 4, May 24 and June 13 in the field and May 24 in the green house. The maximum and minimum temperature of the field, green house and their differences are shown in Table I. 2. For the purpose of determining the ecotypes of soybean varieties, the dates of first blossoms and the times from sowing to the first blossoms of the field and the green house are compared in Table II. 3. The times from sowing to first blossoms of 2 varieties (Okumame and Kanagawa Kosamame) were not shortened by the high temperature of the green house. They were completely controled by the day length, so they are the typical short-day type (so-called autumn type). 4. Independent type (so-called summer type) were not detected. They must be determined by other methods which will be reported in near future.
