Effect Of Spraying Amine Fresh Fat And Mepiquat Chloride At Flowering Stage On Soybean Yield

This experiment was carried out at the Xiangyang test base of Northeast Agricultural University in 2022.Heinong 84（HN84）and Heinong 87（HN87）were used as the test soybean varieties,and water spraying（CK）was used as the control.Spraying different concentrations of amine ester（DTA-6）and mepilium（DPC）at the initial flowering stage（R1）of soybean.The effects of DTA-6 and DPC on morphological characteristics,dry matter accumulation,photosynthetic characteristics,physiological characteristics and yield of soybean were explored.It provides reference value for the popularization and application of regulators in soybean,and has certain theoretical basis and practical significance.The main results are as follows:（1）DTA-6 significantly increased the leaf area,root length,root surface area and root volume of the two varieties.HN84 had the best effect at DTA-6 of 60mg/L,and HN87 had the best effect at DTA-6 of 30mg/L.At the full filling stage（R6）,HN84 increased by 10.8%,9.7%,7.5%and10.4%at the optimum concentration,and HN87 increased by 13.5%,11.0%,14.9%and 16.4%at the optimum concentration.The plant height of the two varieties reached the maximum at the concentration of DTA-6 60mg/L,with an increase of 4.7%and 5.9%,respectively.DPC significantly increased the root length,root surface area and root volume of the two varieties.HN84 had a significant effect at the DPC concentration of 400mg/L and HN87 at the DPC concentration of 200mg/L.At the R6 stage,HN84 increased by 12.4%,12.7%and 9.0%at the optimum concentration,and HN87 increased by 11.5%,15.0%and 10.9%at the optimum concentration.DPC significantly reduced plant height,and the two varieties were most inhibited at400mg/L concentration,with a decrease of 9.2%and 8.4%,respectively.The leaf area was significantly reduced,and the inhibition of HN84 at 400mg/L and HN87 at 200mg/L was the largest,with a decrease of 9.0%and 11.9%,respectively.（2）DTA-6 at 30mg/L significantly increased the leaf dry matter accumulation of the two varieties,and the increase was 34.6%and 21.2%at R6 stage,respectively.HN84 at DTA-6 of60mg/L,HN87 at DTA-6 of 30mg/L significantly increased the dry matter accumulation of stems,petiole,pods and roots.At R6 stage,HN84 increased by 14.7%,29.8%,11.0%and 6.4%,respectively.The increase of HN87 at the optimum concentration was 16.9%,6.0%,11.4%and13.1%,respectively.DPC significantly reduced the dry matter accumulation of leaves,stems and petioles of the two varieties,and significantly increased the dry matter weight of pods and roots.HN84 was most significant at DPC 400mg/L and HN87 at DPC 200mg/L.At R6 stage,the dry matter accumulation of leaves,stems and petioles of HN84 decreased by 6.8%,4.1%and 8.8%,respectively,and that of HN87 decreased by 4.6%,9.5%and 13.4%,respectively.The dry matter accumulation of pods and roots of HN84 increased by 5.3%and 15.3%,respectively,and that of HN87 increased by 17.7%and 16.0%,respectively.（3）DTA-6 and DPC significantly increased relative chlorophyll content（SPAD）,effective quantum yield of photosynthetic system II（Phi2）,quantum yield of regulatory energy dissipation（Phi NPQ）,steady-state fluorescence（Fs）,maximum fluorescence（Fm）,PSII primary light energy conversion efficiency（Fv/Fm）,non-photochemical quenching（NPQ）;the quantum yield of non-regulated energy dissipation（Phi NO）and initial fluorescence（F₀）were significantly reduced.The effect of HN84 was significant at DTA-6 of 60mg/L and HN87 was significant at DTA-6 of30mg/L.At the optimum concentration,the Phi NO of HN84 decreased by 42.3%in the early stage of seed filling（R5）,and the Fm and NPQ increased by 30.5%and 41.9%respectively in R6 period.The Phi2 of HN87 increased by 45.8%in the initial pod stage（R3）,the Phi NPQ increased by39.4%in the R6 period,and the NPQ increased by 68.4%in the full pod stage（R4）.The effect of HN84 was significant at DPC of 400mg/L and HN87 was significant at DPC of 200mg/L.Under the optimum concentration,the Phi NPQ,Fs,Fm and NPQ of HN84 increased by 55.4%,36.4%,36.4%and 31.4%,respectively.The Phi2 of HN87 increased by 47.4%at R3,the Phi NPQ increased by 30.5%at R2,and the NPQ increased by 44.7%at R4.（4）DTA-6 and DPC significantly increased the activities of SOD and POD and decreased the content of MDA in soybean leaves.The effect of HN84 was significant when DTA-6 was 60mg/L and HN87 was 30mg/L.Under the optimum concentration,the SOD activity of the two varieties reached the peak at R4 stage,which increased by 7.7%and 17.6%respectively.The POD activity of HN84 and HN87 reached the maximum at R6 and R5,which increased by 49.8%and 68.1%respectively.The content of MDA reached the maximum at R6 stage,with a decrease of 11.9%and20.8%.The effect of HN84 was significant when DPC was 400mg/L and HN87 was 200mg/L.Under the optimum concentration,the SOD activity of the two varieties reached the peak at R4stage,which increased by 13.5%and 21.9%respectively.The POD activity reached the peak at R6stage,which increased by 21.9%and 93.5%respectively.The content of MDA reached the maximum at R6 stage,with a decrease of 12.0%and 22.0%.（5）DTA-6 and DPC significantly increased the contents of proline,soluble protein and soluble sugar in soybean leaves.The effect of HN84 was significant when DTA-6 was 60mg/L and HN87 was 30mg/L.Under the optimum concentration,the proline content of the two varieties reached the peak at R6 stage,with an increase of 17.8%and 45.0%.The soluble protein content reached the maximum at R4 stage,with an increase of 5.6%and 25.4%.The soluble sugar content was the highest in the R6 period,with an increase of 7.4%and 29.9%.The effect of HN84 was significant when DPC was 400mg/L and HN87 was 200mg/L.Under the optimum concentration,the proline content of the two varieties reached the peak at R6 stage,with an increase of 61.8%and40.5%.The soluble protein content reached the peak at R4 stage,with an increase of 28.1%and24.3%.The soluble sugar content was the highest in the R6 period,with an increase of 8.3%and27.7%.（6）DTA-6 and DPC significantly increased soybean yield.HN84 in DTA-6 is 60mg/L,DPC is 400mg/L;HN87 had the most significant effect when DTA-6 was 30mg/L and DPC was200mg/L.After DTA-6 treatment,the yield of HN84 increased by 5.4%at 60mg/L,and the yield of HN87 increased by 14.5%at 30mg/L.After DPC treatment,the yield of HN84 increased by 23.1%at 400mg/L concentration,and the yield of HN87 increased by 20.4%at 200mg/L concentration.Overall,the effect of DPC is better than DTA-6.