Effects Of Sowing Date On Photosynthetic Characteristics,Nitrogen Utilization,Yield Of Sugarbeet(Beta Vulgaris L.)

Sugarbeet is one of the main sugar crops in China.In order to make more effective use of local photothermal resources,improve the use of light energy and nitrogen utilization of sugarbeet.This test takes the beet variety KWS0143 as the research material to explore the effects of different sowing dates on the photosynthesis characteristics of beets,nitrogen utilization and yield quality.The experiment was carried out in 2019 at the Acheng Test Base of Northeast Agricultural University(127°05’ E,45°53’ N).The experiment was designed with a fully randomized block with different sowing times: April 7(X1),14(X2),21(X3),April 28(X4)in 2019,and there were 3 replicates in each treatment.In addition,4 control groups without nitrogen application were set up on April 7(X11),14(X22),21(X33)and 28(X44)in 2019.The main results were as follows:(1)X1 treatment need unearthed takes more time,the earliest unearthed date,the longest fertility period and the light time is longer.,in turn greater than X2,X3,X4 treatment.X4 treatment unearthed rate is the largest,X1 unearthed rate is the smallest.X3 treatment survival rate is the best,X1 treatment survival rate is the worst Before August 2,the sugarbeets treated under X1 were always more larger than other planting period sowing of dry and fresh weight.(2)X1,X2 treatment sugarbeet Ru BP enzyme activity,leaf area index,photoenergy interception ability on the whole are better than X3,X4 treatment.Between June 23 and August 2,X1,X2 beet plants were significantly more likely to have significantly higher interceptions of photosynthesis effective radiation than X3 and X4,and the light can effectively radiate high utilization rate.X1 sugarbeet plant leaves Y(II)and q L,relative to light protection and net photosynthesis rate overall better than other sowing period treatment.(3)At different sowing periods,the trends of changes in nitric acid reductase(NR),glutamine syntase(GS)and glutamine syntas(GOGAT)in plants were similar,but there were differences in the time of change.Prior to June 23,X1 sugarbeet leaf nitrogen metabolism key enzyme activity was highest,while after July 13,X1 treatment suagebeet leaf NR and GS activity was less than X4 treatment for most of the time.X1 and X2 treatment the NR and GS activity in the root was greater than X3、X4 treatment.(4)Sowing dates advance can promotes beet yield and sugar content.The highest sugar yield and sugar yield under X2 treatment,and the highest sugar content of the root under X1 treatment.In summary,the advance of seeding date has a positive effect on beet yield and sug ar content,and early sowing of beets can make better use of light energy and nitrogen resources.Under this test condition,beet sowing 7 days ahead of the regular planting period(April 21),can make fuller use of light resources and nitrogen,improve the yield and sugar production of beet root.