Abstract: The two winter wheat eultivars used in this study were Tainong18 （T18） and Shannong15 （S15） possessing large and middle ear, respectively. Four regimes of planting density and three nitrogen rates were applied to study the interaction between nitrogen and density on photosynthesis characteristics after anthesis and grain yield to seek a balance between sowing density and nitrogen used under high yield pattern. The results showed that plant- ing density, nitrogen rate and the interaction between them had significant effects on grain yield and photosynthesis characteristics after anthesis. The effect of planting density on canopy photosynthetic rate was mainly reflected in the positive effects of early and mid grain filling stage, and the impact of nitrogen mainly in mid and late grain filling stage. The interaction between nitrogen and density maintained a high canopy apparent photosynthesis rate during the whole grain filling period under high yield pattern. In this study, the appropriate plant density and nitrogen rate of T18 were 90 kg/ha and N 180 kg/ha respectively,while for S15 were 75 kg/ha and N 180 kg/ha. Conclusively, it was possible to adjust nitrogen rate and planting density to take advantage of the interaction between them to a- chieve a higher canopy apparent photosynthesis rate and high grain yield.

Key words: Canopy apparent photosynthesis, Interaction between density and nitrogen, Winter wheat Yield

CLC Number: 

• S512.01