Effects Of Direct-seeding Date On Comprehensive Productivity Of Different Genotypes Of Rice In Huaibei Region

Test in 2008-2009 in Pingming town of Donghai County of Lianyungang Jiangsu at Huaibei region, Conventional early mid-ripe Japonica(CEMRJ),Conventional middle mid-ripe Japonica (CMMRJ),Conventional late mid-ripe Japonica (CLMRJ) and Hybrid late mid-ripe Japonica (HLMRJ) as experimental material, study different sowing date (June 3, June 10, June 17, June 24, July 1) on the different types of species reproductive period of accumulated temperature, yield, population quality, and quality of fertilizer effects conditions in the wheat stubble. In order to produce high quality and high yield for the direct sowing rice at Huaibei region and rational utilization of natural resources efficiently to provide theoretical and practical basis. The main results are as follows:1. The different varieties were all showed that the whole growth period become shorter following the lateness of the seeding time, the changing range was 18-20 days.Changeing of the days from seeding date to heading date was consistent with the whole growth period.The difference of the whole growth period in different types variety depended mainly on the days before heading of rice varieties.2. Accumulated temperature of the whole growth period in different rice varieties were decreased following the lateness of the seeding time, furthermore there are the same result in sunshine time. The difference of accumulated temperature of the whole growth period in different varieties are mainly embodied in the stage from seeding date to heading date, but accumulated temperature after heading was reduced obviously. The utilization ratio of accumulated temperature in different rice varieties were reduced greatly following the lateness of the seeding time.3. The yield was decreased following the lateness of the seeding time, yields of the treatment with the seeding time in June 3 was the highest. The process of the yield formation of the same rice variety, there was a linear negative correlation between spike numbers, grains per spike, seed setting rate, 1000-grain weight and seeding time of direct seeding rice.Under the condition of the same seeding period, there were difference in yields and yield formation of different rice varieties, the total yield of CMMRJ at high level yield (June 3) was the highest, HLMRJ and CLMRJ were secondly, and CEMRJ was the lowest; The spike numbers was showed: CEMRJ>CMMRJ> CLMRJ> HLMRJ: The grains per spike was showed that HLMRJ was the highest, CMMRJ was the lowest, the results showed that HLMRJ had more advantages than CMMRJ; The seed setting rate had great difference too, CEMRJ and CMMRJ were the highest, and 2 different types had little difference. CLMRJ were secondly, and HLMRJ was the lowest. The author proposed that the conventional rice had advantages in seed setting rate compared to the hybrid rice; The 1000-grain weight was showed: CLMRJ> CMMRJ> HLMRJ> CEMRJ.4. There were difference in population quality of different rice varieties, such as tillering dynamics, LAI dynamics, SPAD of leaf, plant height at maturity stage, internode collocation and dry matter accumulation, etc. The treatment of seeding in June 3 behaved the best, and it explained the cause of its high yield.5. N concentration at the main growth period and growing stage was decreased following the lateness of the seeding time. There were difference in N concentration at maturity stage, CLMRJ> HLMRJ> CMMRJ> CEMRJ.6. Different varieties, along with the delayed sowing date, milling quality,Appearance quality deteriorating, Protein content increasing, Amylose content drop, Peak vise,Hot vise,Breskdown,Final visc are gradually reduced; Pasting temp rising, Setback generally shows a rising trend. Description of appropriate sowing time will help improve rice milling quality, appearance quality and Cooking and eating quality, and poor nutrition qualitative change. Under the same sowing date, various types of varieties of rice quality and appearance quality of both differences, CMMRJ is best at milling quality; Appearance quality: CM(E)MRJ> CLMRJ> HLMRJ.The above results show that early direct sowing at Huaibei region is Co-ordinate to achieve high yield, high quality, efficient, ecological, security and other key technology integrated measures of production goals. Direct seeded rice at Huaibei region in general should be chosen CMMRJ.