Study On Double-cropping Cultivation Techniques And Its High Physiological Basic Of New Hybrid Rice Combination Zhuliangyou4024and Hyou159

In this study, early hybrid rice combination Zhuliangyou4024and late combination Hyou159are tested. Dry matter accumulation, yield and its physiological characteristics change of Zhuliangyou4024and Hyou159under different cultivation methods, planting density and nitrogen levels are studied. The results will provide a reference for the formulation of double season high-yield cultivation Techniques of Zhuliangyou4024and Hyou159, and explore the high-yielding physiological basis of the test combination. The main results obtained are as follows:(1) Throwing transplanting cultivation was conducive to Zhuliangyou4024and Hyou159obtain excellent yield. The yield of Zhuliangyou4024and Hyou159under throwing transplanting treatment increased by3.92%and9.05%than its transplanting treatment respectively, and the difference was significant. Under different cultivation methods, seed setting rate and grain weight change of Zhuliangyou4024and Hyou159were little, but the effective panicles was significantly different. The decline of flag leaf SPAD value of early hybrid rice combination Zhuliangyou4024and Jingyou402under throwing transplanting treatment significantly less than its transplanting treatment at late growth stage. At maturity,the flag leaf SPAD values of Zhuliangyou4024under throwing transplanting treatment more than its transplanting treatment5.23%, its decline smaller than its transplanting treatment3.55%.The flag leaf photosynthetic rate of Zhuliangyou4024under throwing transplanting treatment was significantly stronger than its transplanting treatment from13days after heading. The flag leaf SPAD values and photosynthetic rates of Hyou159and Jinyou207under throwing transplanting treatment were higher than their transplanting treatment after heading. The results indicated that higher chlorophyll content and photosynthetic rate and smaller decline rate of the flag leaf of Zhuliangyou4024and H you159under throwing transplanting treatment after heading, were their physiological basis of high yield.(2) Under four different planting density, the yield of Zhuliangyou4024under A2(16.7cmx20cm) treatment was the highest, and the yield of A4(13.3cmx26cm) treatment was the lowest. While the yield of H you159under A3(20cmx20cm) treatment gains the highest yield, A1(13.3cm×20cm) treatment was the lowest. Planting density produces a greater impact to effective panicles and grains per spike of Zhuliangyou4024and H you159, while seed setting rate and grain weight are relatively stable. Total tiller number of Zhuliangyou4024and Jinyou402was effected by basic seedling number large relatively, and increased with planting density increased; Group coordination of H you159was strong relatively, its total tiller number decreasesed with the increase of planting density, maximum tiller stage of H you159along with the decrease of planting density and delay. The leaf area index of Zhuliangyou4024and H you159under different planting density changed vary. The leaf area index of Zhuliangyou4024changed was consensus A1>A2>A4>A3. H you159performanced Al> A2> A4> A3before full heading, and A3> A4> A2> A1after full heading. The A2(16.7cm×20cm) treatment of Zhuliangyou4024and A3(20cmx20cm) treatment of H you159processing higher chlorophyll content and greater photosynthetic rate in flag leaf after full heading, it was the physiological basis of high yield in these densities maybe.(3) Under different nitrogen levels, The yield of Zhuliangyou4024and H you159trends consistent and significant differences between treatments. The yield of N3(180kg/hm2) treatment was the highest, while N1(120kg/hm2) treatment obtained the lowest yield. Total tiller number of Zhuliangyou4024and H you159increasing with nitrogen rate increased, but the total tiller number of N4(225kg/hm2) treatment and N1(120kg/hm2) treatment appeared a larger decline after full heading, while the N3(180kg/hm2) treatment stable relatively. The total biomass of Zhuliangyou4024and H you159performanced N4>N3>N2>N1before full heading. After full heading,each treatment changed was N3> N2> N4> N1. The SPAD value, photosynthetic rate, and SOD activity of Zhuliangyou4024and H you159increased with increasing amount of nitrogen after full heading. and the SPAD value and SOD activity of N4(225kg/hm2) treatment with the smallest decline in the maturation process. The results suggested that increasing the amount of nitrogen fertilization could delay flag leaf senility, but excessive was not conducive to the formation of effective ear, leading to production cuts.(4) The research results indicated that throwing transplanting and nitrogen volume with180kg/hm2were conducive to Zhuliangyou4024and H159obtain excellent yield. The best planting density of Zhuliangyou4024was A2(16.7cm×20cm) treatment, and A3(20cm×20cm) treatment was the most suitable for the growth of H you159and obtained high yield.