[A mechanistic model of phasic and phenological development of wheat. I. Assumption and description of the model].

The temperature effectiveness for wheat development was non-linearized and the apical and phenological development stages were systematically predicted by the scale of physiological development time which was based on the ecophysiological development process. The predicted apical development stages included single ridge stage, double ridge stage, floral initiation stage, stamen and pistil initiation stage, anther seperation stage, tetrad stage, and heading stage, while the predicted phenological development stages included germination stage, emergence stage, tillering stage, winterovering stage, green-turning stage, jointing stage, booting stage, heading stage, flowering stage, grain filling stage, and maturity stage. Four cultivar specific parameters were used to describe the genotypic differences of wheat development. They were temperature sensitivity, physiological vernalization time, photoperiod sensitivity, and intrinsic earliness, reflecting the genetic properties of different cultivars in thermal effectiveness, vernalization, photoperiod response and shortest time required for reaching flowering, respectively. The four parameters determined the physiological development time required for each development stage of different cultivars.