Effects of Planting Density on Grain Yield and Nitrogen Accumulation of Late-Sown Wheat

Cai Wenliang; Li Hui; Fu Lin; Chen Guangzhou; Zhao Kainan; Li Shengdong

doi:10.14083/j.issn.1001-4942.2025.03.008

Abstract：To clarify the effects of planting density on grain yield,agronomic traits,nitrogen accumula-tion,and grain protein content of late-sown wheat,the experiment was carried out by setting different planting densities(D1:3.00 million plants per hectare;D2:3.60 million plants per hectare;D3:4.20 million plants per hectare;D4:4.80 million plants per hectare)for two wheat varieties of Jimai 22 and Shannong 20 in 2021-2022 at the Jiyang Experimental Base of Shangdong Academy of Agricultural Sciences.The results showed that under the conditions of late sowing,planting density had light effects on plant height and spike length of Jimai 22,but the plant height of Shannong 20 under D3 density significantly increased by 5.5％and 6.4％compared with D1 and D2 densities,respectively,and the spike length significantly increased by 8.3％compared with D1 density.The spikelet number of Jimai 22 and Shannong 20 under D3 density was significant-ly higher than that under D4 density by 8.7％and 10.4％,respectively,while the number of sterile spikelet significantly reduced by 28.3％and 37.4％,respectively.Jimai 22 had higher nitrogen accumulation in grains and plants under D3 and D4 densities,while Shannong 20 had the highest nitrogen accumulation under D3 density.Density had no significant effect on total protein content of Jimai 22 and Shannong 20,but significant-ly affected the content of protein components.The contents of albumin and gliadin in Jimai 22 grains were bet-ter under D3 density,which were 17.7％and 21.2％,and 5.0％and 13.9％higher than those under D1 and D2 densities,respectively.The content of gliadin and glutelin in the grains of Shannong 20 were the best under D3 density,and that of gliadin was significantly increased by 45.9％,11.9％and 7.6％compared with D1,D2 and D4 densities,respectively,while that of glutelin was significantly increased by 11.9％and 6.7％com-pared with D1 and D2 densities,respectively.The two varieties had higher spike number under D3 and D4 densities,while the kernels per spike,1 000-grain weight and grain yield reached the highest level under D3 density.The grain yield of Jimai 22 under D3 density was significantly higher than that under D1 density by 11.5％,and that of Shannong 20 was significantly higher than that under D1 and D2 densities by 8.8％and 6.0％,respectively.In summary,under the conditions of late sowing,the agronomic traits of Jimai 22 and Shannong 20 were better under the planting density of 4.20 million plants per hectare(D3),the yield compo-nents were the most reasonable,the nitrogen accumulation in grains was the highest,and the composition of grain protein composition was stable,so the synergistic improvement of grain yield and quality was achieved fi-nally.This conclusion could provide the data support and theoretical basis for planting density selection of Ji-mai 22 and Shannong 20 under late sowing conditions.