The Difference Of Grain Yield And Nitrogen Use Efficiency Between Super Hybrid Rice Varieties

Use the representative varieties of super hybrid rice bred from the first to the fifth issue in recent 15 years Liangyou Peijiu(Approved in 2001),Y Liangyou 1(Approved in2006),Y Liangyou 2(Approved in 2011),Y Liangyou 900(Approved in 2015)and Chaoyou 1000(Approved in 2017)as experimental materials,to study the difference of yield of Super Hybrid Rice at different stages and the effects of nitrogen application rates(0,210,300,390Kg/hm~2)on yield formation,population growth and nitrogen use of super hybrid rice.The result shows:1)To promote the yield of Super Hybrid Rice with the highest representative varieties showed growth and actual yield are recently bred Chaoyou 1000 is the highest,while Y Liangyou 900 of the highest yield,high fertility to Y Liangyou 1 and Y Liangyou 2.The main reason for high yield is large panicle and high seed setting rate.The main reason for the increase of yield in super hybrid rice is that the grain number per panicle increases.2)To improve the level of nitrogen balance in favor of large spike and multi spike contradiction between nitrogen fertilizer and panicle number was significant or very significant positive correlation between Super Hybrid Rice Varieties in the early two hetarosis nine nitrogen and spikelets per panicle were positively correlated,while the amount of nitrogen was significantly negative correlation with harvest index.The yield factors and theoretical yield of all varieties reached a higher level at the level of 300kg/hm~2 application of nitrogen,and the increase of nitrogen application was not large or decreased,but the actual yield was higher when the amount of nitrogen applied in 210kg/hm~2.The amount of nitrogen and the different parts of the leaf area increased significantly or very significantly positive correlation,achieve a higher value of all varieties of leaf area index were nitrogen levels in 300kg/hm~2 fertilizer,nitrogen fertilizer on heading SPAD value and dry matter accumulation were significantly improved and the effect of adding to is not obvious.No significant effects on single stem weight.The panicle rate of super hybrid rice was the highest at low nitrogen level(210kg/hm~2),but the percentage of super elite 1000 was different,and the difference of nitrogen application rate was not significant.The effect of nitrogen rate under 390kg/hm~2 on carbon and nitrogen ratio in different parts of five stage super hybrid rice decreased gradually;The growth indexes of the newly bred Super Hybrid Rice representative varieties Y liangyou 900 and Chaoyou 1000 are of great advantage.3)Among all organs tested varieties at heading and maturity stage of the nitrogen content and nitrogen accumulation and nitrogen fertilizer had significant or very significant positive correlation between nitrogen utilization rate decreased with the increase of nitrogen.Y Liangyou 900 had the highest nitrogen uptake and utilization during the mature period of210kg/hm~2,and the nitrogen uptake and utilization rate reached the highest level in other varieties at the mature stage of 300kg/hm~2.The absorption and utilization rate reached the highest level n 300kg/hm~2 N rate,the nitrogen harvest index,nitrogen use efficiency,nitrogen grain production,nitrogen partial productivity were 210kg/hm~2 to achieve a higher level of nitrogen fertilizer,nitrogen fertilizer on Y Liangyou 900,nitrogen absorption significantly improves the utilization rate and has little effect on the other varieties.In conclusion,under the experimental conditions,210kg/hm~2 fertilizer varieties n level,population growth index,yield structure and actual yield and nitrogen use efficiency have reached a higher level,to promote the nitrogen effect or a negative effect.