本文在信息等级法范围内扩展了表示植物生长年周期特性的生育期概念。用长期观测16个小麦品系所获得3000多个物候数据，包括气温和最高最低生长临界温度，开发和检验了植物生育期数学模型。该模型对各种陆地条件下小麦的物候发育作出了合适、精确的描述。 This paper extends the concept of growth period, which represents the annual cycle of plant growth, within the scope of the Information Grading Act. More than 3000 phenological data were obtained from long-term observations of 16 wheat lines, including the temperature and the maximum and minimum growth critical temperature. Mathematical models of plant growth and development were developed and tested. The model gives a suitable and accurate description of the phenological development of wheat under various land conditions.