Study On The Suitable Density And Sowing Date Of Wheat Dominant Varieties In Henan Province

In order to study the effect of sowing date and density on population stem number,leaf area index,dry matter accumulation,plant height,nitrogen accumulation and translocation,yield and composition of different wheat cultivars.Under field conditions,use different varieties of Aikang58?Bainong207?Xinong979?Zhengmai7698?Zhoumai27 and Zhoumaiapp22 as experimental materials,set two sowing dates(October 18,2016(S1)and November 1,2016(S2));five densities(112.5 kg/hm~2(D1),150 kg/hm~2(D2),187.5 kg/hm~2(D3),225 kg/hm~2(D4),and 262.5 kg/hm~2(D5).The following are the main research result:1 Effect of sowing date and density on population quality of different wheat varietiesThe number of tillers of the tested varieties have a trend that first increased and then decreasd during the growth period,and the peak appeared on jointing stage.The trend of leaf area index followed a similar trend,and the peak appeared on booting stage.Dry matter accumulation and plant height showed a trend of increasing with the progress of the birth process.With the increase of planting density,the number of tillers increased,the leaf area index increased,and the accumulation of dry matter increased.After the sowing date was delayed,the number of tillers in the population decreased,the leaf area index decreased,and the plant height decreased.The accumulation of substances was inconsistent in the tested varieties,among which the dry matter accumulation of Aikang58,Zhengmai7698,Zhoumai27 and Zhoumai22 were S2<S1,and there was a significant difference between treatments,and S1 was comparable to S2,Aikang58,Zhengmai7698,Zhoumai27,Zhoumai22 and other varieties increased by an average of 2.7%-20.6%,0.8%-27.9%,6.2%-17.1%,and 10.4%-41.3% respectively;while Bainong207 and Xinong979 showed S2>S1.Compared with S1,S2 increased by 1.3%-9.5% and 2.3%-26.0% respectively.2 Effect of sowing date and planting density on nitrogen accumulation and translocation in different wheat varieties(1)Effects of sowing date and plant density on nitrogen absorption and accumulation in different wheat varietiesThe nitrogen accumulations of Aikang58,Xinong979,Zhoumai27,Zhoumai22,and Zhengmai7698 showed S1>S2 from emergence to jointing,jointing to flowering and maturity,including Zhoumai27 and Zhoumai22,during the S1 and S2 sowing periods(in various density treatments)was greatly increased,that is,compared with S2,Zhoumai27 increased by 59%-72.9%,13%-44.4%,and 29%-41.4% respectively.Zhoumai22 increased by 44.3%-50.6%,19.5%-41.8%,and 24.1%-39.7% respectively.In flowering to maturity,the nitrogen accumulation of the above five wheat varieties showed S2>S1,S2 Compared with S1,Zhoumai27 and Zhoumai22 that increased by 28.6%-95.2% and 4.7%-83.4% respectively;and the nitrogen accumulation of Bainong207 was from emergence to jointing,jointing to flowering,flowering to maturity and maturity.The performance was S1>S2.Compared with S2,S1 increased by-2.9%-23.7%,9.7%-31.5%,9.3%-27.4%,and 14.6%-22.1% respectively.The above indicators were significantly different.Under different density treatments,the accumulation of nitrogen in different varieties such as Aikang58,Bainong207,Zhoumai27 and Zhoumai22(except for S1 sowing date)increased with the increase in density from emergence to jointing,jointing to flowering and maturity.All of them were maximal under D4 density treatment,while they were maximal under D1 density treatment from flowering to maturity.However,nitrogen accumulations of Xinong979 and Zhengmai7698 varied from jointing to flowering,flowering to maturity and maturity.The increase in density was the highest under the D3 density treatment,and was significantly different from other density treatments.(2)Effect of sowing date and density on nitrogen translocation and distribution of different wheat varietiesThe nitrogen accumulation in grain of each wheat cultivar was the largest in S1(except Zhengmai7698).The translocation and contribution rate of nitrogen before flowering were the largest in S1(except for Bainong207),while the transport amount and contribution rate of nitrogen absorbed after the flower showed the opposite trend.Under different densities,the nitrogen accumulation in grain of all wheat cultivars showed a trend of increased first and then decreased with increasing density.Among them,Aikang58(except S1),Zhoumai27 and Zhoumai22 were all the largest under D4 treatment(During the S2 sowing period,D4 increased by 26.2%,24.2%,and 34.2%,respectively,compared with D1;Xinong979 and Zhengmai7698 were the largest under D3 treatment(D3 increased by 37.8% and 47.1%,respectively,compared to D1);and Bainong207 Grain nitrogen accumulation showed a trend of increasing with the increase of density,that is,D5 was the largest(D5 increased by 36.5% compared with D1),and the above wheat varieties had significant differences among treatments.The number of anthesis N translocations in Aikang58,Zhoumai22,Zhoumai27,and Xinong979(except S2)were the highest under D4 density,while Zhengmai7698 and Bainong207 were in D3 and D5 respectively.Under the treatment,the contribution rate of pre-flower vegetative nitrogen storage was increased with the increase of density(except Zheng Mai7698),and the post-anthesis nitrogen transport amount and contribution rate showed the opposite trend.3 Effect of sowing date and density on grain yield and its components of different wheat varietiesAll the tested varieties had the highest yield of S1 sowing date,and S2 sowing time had lower yield.The grain yield of the tested varieties have a trend that first increased and then decreased with the increase of the density.Among them,the varieties of Aikang58,Bainong207,Zhoumai27 and Zhoumai22 all reached the maximum under the treatment of 225 kg/hm~2(D4).The varieties such as Xinong979 and Zhengmai7698 reached the maximum under the treatment of 187.5 kg/hm~2(D3).Among the yield components,the number of spikes increased with the increase of density,and the number of grains and 1000-grain weight per spike decreased with the increase of the density;after the sowing date was delayed,the number of spikes decreased and the number of grains per ear increased,and the1000-grain weight varied with the varieties.Aikang58,Bainong207,Xinong979,Zhengmai7698 and other varieties of 1000-grain weight increased,while Zhoumai27 and Zhoumai22 and other varieties of the 1000-grain weight showed a trend of reduction.According to the above results,under the experimental conditions,the suitable sowing dates of the tested varieties were all on October 18th;the combination of more than two years of test results shown that the appropriate planting densities of the tested varieties were,the wheat varieties of Bainong207 and Zhengmai7698 were 187.5kg/hm~2;the wheat varieties of Aikang58 were 112.5-187.5kg/hm~2;the wheat varieties of Xinong979 were 150-187.5kg/hm~2;the wheat varieties of Zhoumai27 and Zhoumai22 were 187.5-225 kg/hm~2.