Study On Effect Of Chemical Control And Super-high Yield Cultivation In Double Cropping Rice

In order to explore the double cropping rice yield potential, as well as find out the effect of new regulators to the rice, improve the cultivation techniques of super-high-yield, field experiments were established in Liuyang and Liling city of Hunan province in2012. Under the double cropping rice super-yield cultivation pattern we researched the grain yield and its components, source-sink relation, dry matter accumulation and the radiation use efficiency. The major results were showed as follows:(1) According to the regulation and control goal, using different growth regulators with the same components manufactured to control the rice whole growth stage, The results indicated that, those growth regulators can rise the number of tillers, the number of spikelets per panicle and the work time of leaf, respectively. Using Nongbao in the previous period can enhance the number of tillers, Zhongjiazao17、 Tianyouhuanzhan and Yongyou No. nine the rate of tillers were29.2%,18.8%and19.3%higher than the control, respectively. In the middle growth, using Baominfeng can increase the spikelets per panicle, relative to the control, hongjiazao17、 Tianyouhuanzhan increased by8.9%and5.0%respectively. In the late period using Youkangbao can lengthen the work time of leaf, as well as improve sword leaf photosynthetic efficiency in a period of time and reduce the speed of leaf senescence, which ensure the safety of the group volume capacity effectively.(2) The grain yield and its components under the double cropping rice super-yield cultivation pattern. The yield of early and late rice under super-yield cultivation pattern is significant higher than the local traditional cultivation. The point of Liuyang produced1380kg·667m-2and Liling produced1413kg·667m-2annual,they were higher than that of local traditional cultivation respectively. The key to increase yield is that, under the double cropping rice super-yield cultivation pattern the panicles and filled-grain percentage is significant higher than the local traditional cultivation.(3) Yield-increasing Mechanism of double cropping super-high-yield cultivation pattern. From the analysis of source-sink relation, the total spikelets of super-yield cultivation were higher, which get42000m-2and45474m-2in early and late rice, were 13.8%and12.1%respectively higher than local traditional cultivation mode; and the same with mean leaf area index, which produced2.7and3.5in early and late rice, were28.6%and53.3%respectively higher than local traditional culture model; the plenty of source ensure the normal filled-grain percentage and1000-grain weight. From the analysis of dry matter formation, super-yield cultivation pattern significant more than local traditional cultivation, which produced645.5g·m-2and594.2g·m-2in early and late rice in the period from flowering stage to maturity stage, significantly more than the local traditional cultivation mode, increased by21.5%and74.2%respectively. From the analysis of radiation use efficiency, super-yield cultivation pattern get more radiation from the sun, the total intercept active radiation were more than786.3MJ·m-2and1078.5MJ·m-2in early and late rice, respectively7.3%and5.9%higher than that of traditional cultivation mode, the full use of the gigantic resource, can enhance the radiation use efficiency.In sum, the super-yield cultivation pattern with the growth regulators to control the rice whole growth can significant improve the yield of double cropping rice, make full use of the local light resources, form enough and big panicles to get enough spikelets, coordinate the source-sink relation, which can maintain normal filled-grain percentage and1000-grain weight and get higher yield.