氮密互作对豫南地区籼粳杂交稻产量形成的影响OA

To identify the optimal nitrogen application rate and transplanting density of the indica-japonica hybrid rice Chunyou 167 in southern Henan,this study set three nitrogen application rates(N1 180 kg/hm2,N2 240 kg/hm2,and N3 300 kg/hm2)and four transplanting densities(D1 25 cm×9 cm,D2 25 cm×14 cm,D3 25 cm×19 cm,and D4 25 cm×24 cm),and examined effects of the nitrogen-density interaction on the yield formation.The results showed that the number of tillers per hill at each key growth stage decreased with the increase in the transplanting density under the same nitrogen application rate and increased with the increase in the nitrogen application rate under the same transplanting density,while the number of tillers per group increased with increases in the nitrogen application rate and transplanting density.As the nitrogen application rate and transplanting density increased,the leaf area index and dry matter accumulation at the jointing stage,heading stage,and maturity stage generally showed an increasing trend.Under the same transplanting density,the panicle length,primary branch grain number,secondary branch number,secondary branch grain number,and grain density increased with the increase in the nitrogen application rate.Under the same nitrogen application rate,the panicle length,primary branch number,primary branch grain number,secondary branch number,secondary branch grain number,secondary branch seed setting rate,secondary branch contribution rate,and grain density decreased with the increase in the transplanting density.Under the same transplanting density,the yield increased with the increase in the nitrogen application rate.Under the same nitrogen application rate,the yield first increased and then decreased with the increase in the transplanting density.The yield under the N3D3 treatment was the highest(12.58 t/hm2),which was 1.21％～32.70％higher than that under other treatments.The PLS-PM model analysis showed that the nitrogen application rate had a direct positive effect on the yield,while the transplanting density had a direct negative effect on the yield.The total number of grains per panicle and the number of effective panicles were core traits in response to the nitrogen application rate and transplanting density.In summary,under conditions of this experiment,the yield of indica-japonica hybrid rice Chunyou 167 was the highest in the case of the nitrogen application rate being 300 kg/hm2 and transplanting with the row and plant spacing of 25 cm×19 cm in southern Henan.