播期、品种类型对水稻产量、生育期及温光利用的影响

【目的】研究稻-麦两熟制下，播期与品种类型对水稻产量、生育期及温光利用的影响，为播期及品种类型的科学选用提供依据。【方法】以中熟晚粳、早熟晚粳、迟熟中粳、中熟中粳和迟熟中籼5个品种类型水稻为供试材料，设置4个播期，研究各品种类型水稻产量、生育表现及温光资源利用特点。【结果】不同品种类型水稻产量表现为迟熟中粳＞早熟晚粳＞中熟中粳＞迟熟中籼＞中熟晚粳。随着播期推迟，5个品种类型水稻产量呈下降趋势，但下降程度不等。不同品种类型水稻的减产幅度表现为中熟晚粳＞迟熟中籼＞早熟晚粳＞迟熟中粳＞中熟中粳。同一播期各品种类型水稻之间产量差异有随播期的推迟而增大的趋势。随播期的推迟，各品种类型水稻的生育进程延迟、生育期缩短，全生育期积温和光照时数极显著减少。播期对不同品种类型水稻温光资源利用率的影响按生育期长短分为两类，对生育期较短的中熟中粳及迟熟中籼影响较小，对生育期较长的迟熟中粳、早熟晚粳及中熟晚粳影响较大。对不同播期选择的适宜品种类型进行初步分类为：5月中旬应选用早熟晚粳，搭配迟熟中粳、中熟中粳和迟熟中籼；5月下旬应选用迟熟中粳，搭配早熟晚粳、中熟中粳和迟熟中籼；6月上旬应选用迟熟中粳，搭配中熟中粳和早熟晚粳；6月中旬应选用中熟中粳。【结论】随播期的推迟，5个水稻品种类型产量、生育期及温光利用均呈下降趋势。综合考虑稻麦两熟制与热量条件因素，初步明确了不同播期应选择的适宜品种类型,供大面积生产参考。

Effects of Seeding Date and Variety Type on Yield,Growth Stage and Utilization of Temperature and Sunshine in Rice

【Objective】This study was conducted to investigate the effects of seeding date and variety type on yield, growth stage and utilization of temperature and sunshine under the rice-wheat cropping system in midland of Jiangsu Province. The result will provide a theoretical basis for scientific use of the seeding date and adoption of suitable variety types.【Method】With medium-maturing late Japonica rice varieties, early-maturing late Japonica rice varieties, late-maturing medium Japonica rice varieties, medium-maturing medium Japonica rice varieties and late-maturing medium Indica rice varieties as materials, using four seeding dates, a comparative study of seeding date and variety type on yield, growth stage and utilization of temperature and illumination was conducted.【Result】The grian productivity of different variety types showed that late-maturing medium Japonica rice varieties＞early-maturing late Japonica rice varieties＞medium-maturing medium Japonica rice varieties＞late-maturing medium Indica rice varieties＞medium-maturing late Japonica rice varieties. With delay of seeding date, the grain yields of the five rice variety types all decreased significantly, but the decrements varied. The yields decreasing range of different variety types showed that medium-maturing late japonica rice varieties＞late-maturing medium indica rice varieties＞early-maturing late japonica rice varieties＞late-maturing medium japonica rice varieties＞medium-maturing medium japonica rice varieties. With the delay of seeding date, the growth process of all the varieties delayed and the growth stages of all the variety types shortened, the accumulated temperature and illumination hours for growth stages significantly reduced. In the same seeding date, the yield discrepancy among different varieties showed an increasing trend with the delay of seeding date. According to the growth stage, the effect of seeding date on the utilization rate of temperature and light resources of different variety types could be divided into two categories, one was the little influence on the short growth period which were medium-maturing medium japonica rice varieties and late-maturing medium indica rice varieties，the other was the great influence on the long growth period which were late-maturing medium japonica rice varieties, early-maturing late japonica rice varieties and medium-maturing late japonica rice varieties. The suitable variety types were preliminarily regionalized based on the different seeding dates as follows: early-maturing late japonica rice varieties and late-maturing medium japonica rice varieties, medium-maturing medium japonica rice varieties, late-maturing medium indica rice varieties should be adopted in Mid-May; late-maturing medium japonica rice varieties and early-maturing late japonica rice varieties, medium-maturing medium japonica rice varieties, late-maturing medium indica rice varieties should be adopted in late May; late-maturing medium japonica rice varieties and medium-maturing medium japonica rice varieties and early-maturing late japonica rice varieties should be adopted in early June; medium-maturing medium japonica rice varieties should be adopted in mid-June. 【Conclusion】 With the delay of seeding date, the grain yield, days of growth stage and utilization of temperature and illumination of the five rice variety types all decreased. Considering the rice-wheat cropping systems and heat conditions, a preliminary division for adopting suitable variety types of different seeding date was made, in order to provide reference for rice production in large area.