| Conventional rice Zhongjiazao17 and hybrid rice Rongyou308 were used as materials,by setting different sowing rate to shape different mechanical-transplanted uniformity populations,with manual uniformity transplanting as the contrast,to explore the effect degree of different mechanical-transplanted uniformity populations on the formation of spike from the tillers,light utilization,material production and yield formation;Conventional rice Jiangzao361 and hybrid rice Rongyou308 were used as materials,setting two n fertilization treatment and three configurations of planting strains numbers and seedling numbers,under the conditions of the same basic seeding,to explore the effect degree of reduced seedlings and increased density on the formation of spike from the tillers,light utilization,material production and yield formation.The main results as follows:1.Study on the Uniformity of Mechanical-transplanted Double Rice Under Different Seeding Rates and Its Effects on the Formation of Grain YieldCompared with manual uniformity transplanting contrast,different populations based on different sowing rate due to leakage rate was high,the coefficient of variation of seedlings per stalk was high,population uniformity were poor,which leading to lower spike rate,spike number reduced,the ability of the population to intercept light decreased,material production were reduced,yield decreased significantly.In addition,the result shows that with the sowing rate increased,the uniformity of mechanical-transplanted improved,the difference between mechanical-transplanted treatments and manual uniformity transplanting contrast treatments became small.Under the condition of mechanical-transplanted early rice,with the sowing rate increased,the uniformity of mechanical-transplanted was improved,the yield reduction percentage between mechanical-transplanted treatments and manual uniformity transplanting contrast treatments became small.But when the sowing rate reached 90 g/tray and exceed it,the yield of mechanical-transplanted treatments and manual uniformity transplanting contrast treatments were all appeared a decreasing trend,thus the sowing rate per tray of early rice should be controlled in 90 g/tray.Under the condition of mechanical-transplanted late rice,when the sowing rate less than 90 g/tray,the uniformity of mechanical-transplanted improved with the sowing rate increased,the yield reduction percentage between mechanical-transplanted treatments and manual uniformity transplanting contrast treatments became small,but when the sowing rate exceed 90 g/tray,although the uniformity of mechanical-transplanted improved,the yield reduction percentage became higher,so the sowing rate per tray of late rice should be controlled in 70～90 g/tray.The results showed that under the condition of mechanical-transplanted,the uniformity of mechanical-transplanted was important influential factors of the yield of mechanical-transplanted rice,by added the suitable sowing rate could improve the uniformity of mechanical-transplanted and the yield.2.The Effects of Reduced Seedlings and Increased Density on the Formation of Double Mechanical-transplanted Rice’s YieldUnder the condition of the same basic seeding,the yield of early rice reached highest in the treatment of nitrogen rate was 165 kg/hm2,configurations of planting strains numbers and seedling numbers was an seedling per point and its plant spacing was25×7.5cm,the yield of late rice reached highest in the treatment of nitrogen rate was 195kg/hm2,configurations of planting strains numbers and seedling numbers was an seedling per point and its plant spacing was 25×7.5cm.The results showed under the condition of three configurations of planting strains numbers and seedling numbers,the yield of the treatment of an seedling per point and its plant spacing was 25×7.5cm reached highest,because it beneficial to improve the percentage of available tiller,and its peak seedling,effective panicle were higher.The yield components showed that,compared with the other two configurations of planting strains numbers and seedling numbers,under the condition of the configurations of planting strains numbers and seedling numbers was an seedling per point and its plant spacing was 25×7.5cm,its grain number per panicle decreased,but its effective panicle increased significantly,total number of spikelets became higher,the yield increased.In addition,the result shows that under the condition of the same of configurations of planting strains numbers and seedling numbers,with n fertilization increased,the yield decreased. |
