STUDY ON SOYBEAN ECOLOGY XII. THE PRINCIPLE OF LIGHT LENGTH DIVISION,THE RELATIONSHIP BETWEEN THE COMPREHENSIVE EFFECT OF LIGHT AND TEMPERATURE AND THE GROWTH AND DEVELOPMENT OF WILD SOYBEAN(G. SOJA)

The daylength 5.1% shorter than natural critical flowering photoperiod is short daylength; 5.1% longer than natural critical flowering photoperiod is long daylength ; the rest is suitable daylength. 2. Under short daylength the flowering node is definited by the sensitive effect of cotyledon and rolled leaf; under long daylength the flowering node is definited by the comprehensive effect of range of temperature decrease and long daylength effect of leaf. 3. The flowering node is the index of growth and development that reflects the light length. 4. When the temperature decreases from budding to poding under short daylength, the development is promoted and abnormal pod appears;when the temperature ises from budding to podding under long daylength, the vegetative growth is promoted and the podding is delayed. 5. The natural trend of light and temperature between 25°N and 50°N is the essential condition to form annual wild so bean.