The Temperature-Light Characteristics Of Safe Growth And Yield Formation Of Rice And Its Application In Jiangsu Province

Rice is the most principal grain crop in Jiangsu province so much as in China. For long ages, the increasing consumption requirement for grain is always an important developing power of rice production. Reviewed the development course of rice production in Jiangsu province, the optimizing adjustment of rice production, which attached an importance to planting regionalization and varieties allocating, not only have played an important role in increasing rice yield, but also have become the strategic measure to develop sustainedly rice production in the future in order to utilize highly the climatic resource of temperature and light during rice growing season and to develop the potential productivity capacity of rice varieties. At the same time, the strategic signification of correlative researches about it have been showed adequately by reason of some existent and latent problems needed to solve urgently in present production. Therefor, we had taken Kunshan (31.3,N), Yangzhou (32.4,N), Jianhu (33.4,>J), Suqian (34.0,N), Donghai (34.5,N), Peixian (34.7,N) as experiment areas with different climatic ecology conditions during 1997-2000. In this study, the representative varieties with different mature period types in Jiangsu practical production were selected as experimental materials, and The study is designed to determine regional planning of rice varieties and cultivation according to these varieties in response to temperature-light conditions, and concluded basic laws of safe growth and yield formation in these varieties grown under different temperature-light condition. The main results were showed as follows:1 .Based on improving on the methods of constructing model and fitting parameters, the development simulation model on temperature and light of different types of varieties have been set up by applying the seeding date experimental data in latitudinal regions. This model has the better explanation because it has come over some defect of the old ones, and it adapts to the practice and forecasts precision in the further sense. The analytic result of the model has showed that there are apparent differences among different varieties growth stage in the way of reaction to the condition of temperature and light. The temperature-light sensitivity of developing rate from seeding to heading was MMLJ (medium-maturing late Japonica)>EML3 (early-maturing late Japonica)>LMMJ (late -maturing medium Japonicci)>MMM3 (medium maturing medium Jqpom'ca)>EMMJ (early -maturing medium Japonica)>HM[ (hybrid middle Indicct). But the developing rate from heading to maturing was nearly contrary to that before heading. Theseasonal distribution and the latitudinal change of heading dates and maturing dates of rice varieties in Jiangsu province are defined under normal climatic condition. The difference was small among latitudes but was big among seedings in early-maturing varieties. The growth stage of late -maturing varieties were delayed, as well as the varieties in north region of Jiangsu province and those late-sowed. The maturation index of safe growth, which was ratio of the normal seasonal days of rice growing from earliest seeding to latest safe heading to rice growing days from seeding to the latest safe heading, was used to describe the maturation security and its variation in rice. The maturation securities of varieties would be reduced when they were planted in the north regions of Jiangsu or their seeding dates were delayed. We could determine the latest seeding date and critical latitude of safe maturation of different types of varieties according to the equation in which the relationship of maturation index of safe growth and latitude, seeding date are depicted, in the further step, make regionalizing estimation in varieties.2. The variance analysis of yield in latitudinal regions showed that the regional and seasonal differences of temperature and light had the remarkable effect on the yield of varieties. In north of Jiangsu province, the yields of MMMJ and LMMJ were relatively higher, and that of EMMJ and MMM...