THE RELATIONS OF THE GROWTH OF WINTER WHAET AND THE FORMA-TION OF ITS YIELD PRODUCTIVITY TO METEOROLOGICAL CONDITIONS AND THEIR DYNAMIC SIMULATION With the materials of Huang-Huai Plain of Henan Province

Based on a great amount of field-experimental and meteorological data, authors analysed the quantitative relations of the growth of winter wheat and its yield formation to meteorological conditions and the characteristics of the relations both in time and space by the view of matter cycling and energy transfering in the middle-low yield area of Huang-Huai plain of Henan province, and the vertical distribution features of photosynthetically active radiation (PAR) in wheat colony were pointed out. There is a layer strongly diminishing PAR in wheat population. And the layer tends to be higher as the wheat growing. Based on different features of the course of winter wheat in this region, four growth patterns were classified, which are early sowing, suitable sowing, delayed sowing, and freezing injury growth pattern. With the reviewing of previous research works, the authors have developed a model "Winter Wheat Agrometeorological Computer Simulation Model (WWACSM)", which comprises three first class submodels: Growth Duration, Leaf Area Index, and photosynthesis submodel, and a number of second class models. Some of the submodels were investigated and improved, which then provided meteorological basis for further development of wheat' production in this district.