The Relationship Between Growth Characteristics And Yield Of Directeded Rice

The way of direct seeding of rice has been accepted by people gradually,and it faces the rick of reduced production during the production of direct-seeded rice.Therefore,it is of instructive importance to determine the relationship between growth characteristics and yield of direct-seeded rice.This experiment was divided into three parts.In first part,the hybrid rice variety of Y Liangyou 087 was used to set up three seeding rate,namely,M1.5(22.5 kg.ha^-1),M2.5(37.5 kg.ha^-1)and M3.5(52.5 kg.ha^-1).The optimal seeding rate was determined through the test and a comparison of yield and quality was made between this optimal seeding rate and other seeding rates.In second part,the optimum seeding rate of direct seeding rice was compared with that of normal hand transplanted and throwing rice,and thus to determine the relationship between the growth characteristics and yield composition of Y Liangyou 087.In the third part,china Academic Journals Full-text Database was used to search the literature of direct-seeded rice,and the characteristics of intercropping,yield and dry matter accumulation and the correlation among them were analyzed by using the data obtained from the literature.The main research results were as follows:?1?Seeding rate significantly affected the yield and group quality of direct-seeded rice.With the increase of seeding rate,the Spikelets per panicle decreased and Panicles per m2 increased.The higher the seeding rate,the sooner it reached the highly Tillering period;With the increase of seeding rate,the leaf area index increases,the photosynthetic potential increases,the effective leaf area rate increases,and the blade attenuation block increases.With the increase of seeding rate,the dry matter accumulation increases.?2?Direct-seeded rice growth shows“?”characteristics.The index of leaf area and photosynthetic potential of direct-seeded rice were lower than that of the control group,but there was no significant difference with the control group at medium period.The proportion of dry matter accumulation in the early and late stages of direct seeding rice was smaller than that of the control group;and the total material accumulation was smaller than that of the control group of hand and cast seeding;and the output rate and the operation rate of the direct seeding rice were greater than that of hand transplanted one but less than that of throwing rice.The accumulation and proportion of nitrogen in the later stage of direct seeding rice were smaller than that of hand transplanted rice,but the proportion of nitrogen accumulation in the mid-term was larger than that of the control group.The flow rate of single stem injury of direct seeding rice after heading was small,and the flow rate of single stem injury decreased rapidly;however,the difference between the group flow rate and flow rate of the control group was not significant.That is to say,direct-seeded rice has the characteristics of weak growth in the early and late stages and strong medium-term characteristics.?3?Under different cultivation conditions,the yield,yield component and dry matter accumulation of direct seeding showed obvious fluctuation.In the four yield components,the volatility of the effective panicles was higher than that of the yield,but its correlation with the yield was not significant;and the volatility of the grains per panicle was not only greater than the yield,but also was significantly correlated with the yield.The fluctuation of seed setting rate and 1000 Kernel Weight is less than that of the yield and is not significantlycorrelated with the yield.The dry matter accumulation of direct-seeded rice showed different ?-shaped characteristics at different growth stages,and the fluctuation of dry matter accumulation in different growth stages showed obvious ?-shaped characteristics.The dry matter accumulation in the early growth stage is the smallest while the volatility is the largest.The dry matter accumulation in the middle period is the largest while the volatility is the smallest.The quantity and volatility of the dry matter accumulation in the late growth period are between ones in the early and the middle stage.The relationship between dry matter accumulation and yield was not significant at the early and middle stages,but it was significant at later stage.