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Agricultural industry

Breakthrough in Crop Research: DA-6 Regulator Optimize Soybean Growth and Yield in Maize-Soybean Strip Intercropping

Strategic Insights

— 2 min read

Researchers from Sichuan Agricultural University have made a significant discovery in the field of crop research, revealing that the exogenous plant growth regulator, diethyl aminoethyl hexanoate (DA-6), in combination with suitable varieties and planting densities, is crucial in increasing yield in the maize-soybean strip intercropping system. The two-year field experiment examined changes in branching architecture and other yield traits of soybeans in maize-soybean strip intercropping systems, resulting in a 22.4% to 30.0% increase in soybean yield when applying DA-6 at 60 mg L-1 at the fourth trifoliolate leaf stage.

Key Takeaways:

  • The exogenous plant growth regulator, diethyl aminoethyl hexanoate (DA-6), in combination with suitable varieties and planting densities, is essential in increasing yield in the maize-soybean strip intercropping system.
  • The research involved a two-year field experiment examining changes in branching architecture and other yield traits of soybeans in maize-soybean strip intercropping systems.
  • Applying DA-6 at 60 mg L-1 at the fourth trifoliolate leaf stage increased soybean yield, with QH yield rising by 22.4% and 29.5% at D3 density, and ND yield by 29.5% and 30.0% at D2 density in 2022 and 2023, respectively.
  • DA-6 improved photosynthesis in both varieties under D2 density, with DA60 increasing ND canopy photosynthetic rate by 15.1%-16.4% and QG by 9.1%-20.6% over two years.
  • In ND, DA-6 enhanced branching, raising the leaf area index by 37%, branch number from 3.6 to 4.7 per plant, and total pod number by 19.7%.
  • In QH, yield grains were mainly due to a 17% increase in the number of stem pods and a 6.5% improvement in hundred-grain weight.
  • The research concluded that QH achieved a high yield by forming a high-density (D2 to D3) main stem pod, and ND by combining moderate density (D1 to D2) with DA-6-induced branching.

Statistics:

  • The researchers used two soybean cultivars, Nandou 25 (ND) and Qihuang 34 (QH), under three planting densities (D1: 102,000 plants ha-1, D2: 130,000 plants ha-1, D3: 158,000 plants ha-1).
  • DA-6 was applied at 60 mg L-1 at the fourth trifoliolate leaf stage, resulting in a 22.4% to 30.0% increase in soybean yield.
  • DA-6 improved photosynthesis in both varieties under D2 density, with a 15.1%-16.4% increase in ND canopy photosynthetic rate and a 9.1%-20.6% increase in QG.
  • The leaf area index increased by 37% in ND, branch number increased from 3.6 to 4.7 per plant, and total pod number increased by 19.7% in ND.

Sources:

  • Diethyl aminoethyl hexanoate (DA-6) and planting density optimize soybean growth and yield formation in maize-soybean strip intercropping. Crop Journal, 2025, 13(4):1259-1270.
  • Crop Journal - http://www.sciencedirect.com/science/journal/22145141/
  • The publisher for Crop Journal is KeAi Communications Co., Ltd.
  • A free version of this journal article is available at https://doi-org.sdpl.idm.oclc.org/10.1016/j.cj.2025.06.008.

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