Effects Of Sowing Date And Planting Density On Grain Yield,Quality And Nitrogen Use Efficiency Of Strong Gluten Wheat

The field experiments were carried out in 2019–2020 at the experimental station of Dongwu Village,in Dawenkou Town,Daiyue District,Tai’an,Shandong,P.R.China the planted cultivar is strong gluten wheat“Zhouyuan 9369”was selected as the experimental material.The winter wheat were sown on two dates（conventional sowing on 8 October and delayed sowing on 22 October）and plant densities of 300 and 450 plants m^-2,the responses of grain yield,quality and nitrogen use efficiency.The main results are shown as follows:The effect of sowing date was significant on the grain yield,NUE,UTE and UPE,and had no effect on water gluten content,water absorption,development time stability time,loaf volume and loaf score.plant density had no effect on the grain yield,NUE,UTE,UPE,water gluten content,water absorption,development time,stability time,loaf volume and loaf score.The interaction of plant density and sowing date was not significant on the grain yield,NUE,UTE,UPE,water gluten content,water absorption,development time,stability time,loaf volume and loaf score.1 The grain yield as affected by plant density,sowing date of strong gluten wheatAt the same plant density,the grain yield of strong gluten wheat significantly increased with the increasing sowing date,and there was no obvious difference between the density treatments,and the highest grain yield was the delayed sowing date（October 22）and the planting density was 450 plants m^-2.At the same sowing date,the spike number of strong gluten wheat showed an increasing trend with the increase of density（the increase is 13.32%）,while the number of kernels per spike showed a decreasing trend（the decrease of 10.72%）.At the same planting density,the spike number of strong gluten wheat showed a decrease with the delay of sowing date（the decrease of 3.58%）.The number of kernels per spike showed an increasing trend（the increase is 16.42%）.Under different sowing dates and planting densities,the kernel weigh of strong gluten wheat had no significant difference.It shows that the increase in the number of the spike number compensates for the negative impact of the decrease in kernels per spike,and the yield remains unchanged due to the influence of planting density.However,under different sowing dates,the increase in the spike number is higher than the decrease in kernels per spike.The grain yield increased significantly under conditions of postponed sowing date（22 October）.At the same sowing date,as the density increases,there is no significant difference in the total dry matter accumulation of strong gluten wheat during wintering,jointing,flowering and maturity.However,under the same density conditions,as the sowing date is delayed,the strong gluten wheat the total dry matter accumulation of gluten wheat in the wintering and jointing stages showed a decreasing trend with the delay of the sowing date,but the mature stage showed an increasing trend with the increase of planting density,and there was no significant difference in the flowering stage.It shows that postponing the sowing date and increasing the density is beneficial to the dry matter accumulation during the mature period,but increasing the density during the conventional sowing date is beneficial to the dry matter accumulation before flowering.2 The effect of sowing date and planting density on the quality of strong gluten wheatUnder the experimental conditions,there were no significant differences in water gluten content,water absorption,development time,stability time,loaf volume and loaf score of strong gluten wheat between different sowing dates and planting density treatments.It shows that the quality traits of strong gluten wheat"Zhouyuan 9369"are generally stable,and are less affected by the sowing date and planting density,which is conducive to high-quality cultivation.3 The effect of sowing date and planting density on nitrogen utilization efficiency of strong gluten wheatNitrogen use efficiency is the ratio of grain yield to nitrogen supply.At the same density conditions,nitrogen use efficiency increases with the delay of the sowing date,but there is no significant difference between the densities.It shows that postponing the sowing date can coordinately increase the grain yield and nitrogen use efficiency of strong gluten wheat.At the same density conditions,the nitrogen uptake efficiency and the nitrogen utilization efficiency show an increasing trend with the delay of the sowing date,while the grain nitrogen content shows a decreasing trend with the delay of the sowing date,but the nitrogen uptake efficiency and nitrogen.There was no significant difference in the nitrogen uptake efficiency,nitrogen utilization efficiency and grain N concentration among densities.Under the condition of postponed sowing date,the grain N concentration was reduced and the utilization efficiency of nitrogen was improved.It showed that the capacity of postponed sowing date treatment to use absorbed nitrogen for grain production was higher than that of conventional sowing date treatment.Under the conditions of this experiment,postponing the sowing date resulted in an increasing trend of nitrogen uptake efficiency and nitrogen utilization efficiency,so that the nitrogen utilization rate showed an increasing trend under the condition of delayed sowing.