Foliar Spraying Of Different Chemical Control Compounds Regulation Of Soybean Growth And Yield And Quality

Soybean(Glycine max L.)plays an important role in food and feed crop in the world,and its yield level and quality have always been the focus of many scholars at home and abroad.At present,our country’s soybean supply exceeds demand and still relies on imports.Therefore,increasing soybean yield per unit area,improving soybean quality,and increasing my country’s soybean selfsufficiency rate are the bottlenecks that need to be solved urgently in soybean production.In this study Prohexadione-calcium(Pro-Ca)was mixed with Diethyl aminoethyl hexanoate(DA-6)or Brassinolide(BR)to generate compounds LMA and LMB to explore their effects on soybean growth and development,physiological metabolism and the formation of yield and quality.The study was conducted in 2021 and 2022 at the experimental site in Anda,using Heilongjiang Province soybean cultivars Heinong 84(high protein variety)and Heinong 87(high oil variety)as test materials.Foliar sprays were applied at key periods of soybean growth and development(seedling stage,beginning-flower stage stage and seed filling stage)In the foliar spraying and 7days after spraying period beginning-flower stage,samples were taken to investigate the related indicators of morphological establishment,dry matter accumulation,carbon and nitrogen metabolism,yield and quality of each treatment,and initially revealed different growth.During the period,the preliminary study reveals the effects of spraying chemical control compound on the growth and development,physiological metabolism,yield and quality of soybean in the later period,as well as providing a reference for chemical control technology for improving soybean production level.the main test results are as follows:1.In the 2021 experiment,it was found that spraying LMA at the seedling stage and spraying LMB at the beginning-flower stage and seed filling stage(ABB treatment)had the most significant effect on increasing soybean yield,which could increase the theoretical yield of Heinong 84 and Heinong 87 respectively compared with the control 19.40% and 32.66%,and the difference between Heinong 87 was significant(P<0.05).The increase of soybean yield by ABB treatment was mainly due to the increase of 100-grain weight.The control was significantly improved by9.21% and 14.20%.In addition,spraying LMA at the seedling stage and spraying LMB beginningflower stage(AB treatment)also had an ideal yield-increasing effect on soybean in Heinong 84 and Heinong 87.The experiment in 2022 found that spraying LMA at the seedling stage and spraying LMB beginning-flower stage(AB-V1 treatment)had the best yield-increasing effect.The theoretical yield was increased by 33.30% and 20.79% in Heinong 84 and Heinong 87,respectively,compared with the control,and the difference was significant in Heinong 84(P<0.05)and 14.97% and 15.36%,respectively,as compared with the spraying of polyazolium-mepiquat(C-R1 treatment)at the beginning-flower stage.At the same time,spraying LMA at the seedling stage in 2022,spraying LMB beginning-flower stage and seed filling stage(ABB-V1 treatment)significantly increased the number of pods of Heinong 84 and the weight of 100 seeds of Heinong87.The yield of Heinong 87 increased by 21.22% and 16.98% compared with the control,and increased by 4.54% and 11.72% compared with the C-R1 treatment.2.In the 2021 experiment,it was found that spraying LMA(AA treatment)at the seedling and the beginning-flower stage,respectively,significantly increased the total protein content,while spraying LMA(AAA treatment)again at seed filling stage also enhanced the total protein content,which shows that the compound LMA was more effective in increasing the total protein content.As for fat content,none of the treatments reached significant levels of difference in both varieties at the same time,so the increase in fat content of soybean by both combinations was small.In the 2022 experiment total protein content of soybean increased compared to the control except for the seedling stage spray LMA(A-V1 treatment)which decreased compared to the control,but only the ABB-V1 treatment reached significant(P<0.05)levels in both varieties,which increased by 9.28% and 9.88%,respectively,compared to the control.The AB-V1 treatment and ABB-V1 treatment were found to enhance soybean fat content in the 2022 experiment,but still did not reach significant levels.3.In the 2021 experiment,the ABB treatment had the most significant effect on the morphological establishment and dry matter accumulation of Heinong 84 and Heinong 87 plants,while the AB and AA treatments also had a good effect on the accumulation of dry matter of different varieties.In the 2022 experiment,ABB-V1 treatment had the best effect on morphological establishment and aboveground dry matter accumulation of different soybean varieties,followed by C-R1 treatment and AB-V1 treatment.4.In the 2022 experiment,C-R1,AB-V1 and ABB-V1 treatments were found to be effective in enhancing sucrose,fructose,soluble sugars and starch content in soybean leaves,thus promoting assimilate accumulation in leaves.In addition,C-R1 treatment was the most effective in increasing sucrose synthase(SS)and sucrose phosphate synthase(SPS)activities,followed by AB-V1 treatment.ABB-V1 treatment and AB-V1 treatment significantly increased α-amylase and β-amylase contents in leaves,promoted starch degradation,and increased storage of material in the seeds.5.In the 2022 experiment,seedling sprays of LMA(A-V1 treatment),AB-V1 and ABB-V1 treatments were more effective in increasing glutamine synthetase(GS)and glutamate synthase(GOGAT)activities in soybean.The AB-V1 treatment had the most significant effect on the enhancement of glutamate dehydrogenase(GDH)activity in Heinong 84 and Heinong 87,followed by ABB-V1 treatment and C-R1 treatment,respectively,while AB-V1 and ABB-V1 also had significant effects on the amino acid content and soluble protein content in the leaves.In conclusion,AB-V1 treatment was effective in improving soybean leaf carbon and nitrogen metabolism,promoting seed protein storage,promoting soybean morphogenesis and dry matter accumulation,increasing soybean 100-grain weight,and thus improving yield.ABB-V1 treatment was second only to AB-V1 treatment in its effect.