Growth And Yield Formation Characteristics Of Direct-seeded Rice In Cold Area

The trial was implemented by a set of field comparison experiment. Using Daohuaxiang 2 as the tested rice cultivar, set up three kinds of cultivation mode, transplanted rice, no-tillage direct-seeded, and ridge direct-seeded. All treatments above adopted optimized fertilization. Researching effect of different cultivation mode on the growth and yield formation of rice based on the nutrition management. The main results were as follows:Compared with transplanted rice, the time of direct-seeded rice into seedling stage was 31-32 days later, transplanted rice came into into the panicle initiation first, earlier than that of direct-seeded rice by 10 days, and the time into mature stage 6 days earlier; but the whole growth period was 25-26 days shorter, of which the time before panicle initiation stage was 20 days shorter.Direct-seeding method can significantly improve the population structure of direct-seeded rice, increase weight per stem leaf sheaths, improve the earbearing rate,. The population structure of direct-seeded rice was the most reasonable, earbearing rate is highest, reached more than 80%.Direct-seeding can ensure suitable dry matter accumulation of direct-seeded rice in early days, and more dry matter accumulation after heading, the material net assimilation amount and the assimilation rate on grain yield of the direct-seeded rice significantly higher that of transplanted rice.Compared with transplanted rice, direct-seeded rice showed the follow effects: effective panicle number reduced, seed setting rate and number of kernels per spike increased, there was no significant difference among 1000-grain weight and yield. The spike grain number of no-till and ridging direct-seeded rice higher than that of transplanted rice by 24.4 and 27(P < 0.01). The seed setting rate of no-till direct-seeded rice was 2.2% higher than that of transplanted rice, ridge directed-seeded was 3.9%. The highest yield of this experiment is transplanted rice and ridge directed-seeded rice, which reached 7.65 t·ha-1, no-till direct-seeded rice was lower than transplanted rice, but no significant difference.