Plant growth regulators that can be used as fertilizer enhancers and their mechanisms of action

Plant growth regulators that can be used as fertilizer enhancers mainly improve fertilizer utilization by promoting plant absorption, transport and utilization efficiency of nutrients, or enhancing plant metabolic activity. The following are some common plant growth regulators with fertilizer synergistic effects and their mechanisms of action:


1. Auxins
Representative substances: Indole-3-Butyric Acid (IBA), 1-Naphthyl Acetic Acid (NAA)
Synergistic mechanism:
Promote root development, expand absorption area, and enhance the absorption capacity of nitrogen, phosphorus, and potassium.
Combined with fertilizers can improve the activation efficiency of insoluble phosphorus in the soil.

2. Cytokinins
Representative substances: 6-Benzylaminopurine (6-BA), 6-Furfurylamino-purine (Kinetin) (KT)
Synergistic mechanism:
Delay leaf senescence, prolong photosynthesis time, and promote carbon and nitrogen metabolic balance.
Improve the utilization rate of nitrogen fertilizer by plants and reduce nitrogen loss.

3. Brassinosteroids, BR
Representative substance: 24-Epibrassinolide
Synergistic mechanism:
Enhance plant resistance to stress (such as drought and salt damage) and reduce nutrient waste under adverse conditions.
Promote the transport of photosynthetic products to grains and improve the utilization efficiency of potassium fertilizer.


4. Paclobutrazol, PP333
Synergistic mechanism:
Inhibit gibberellin synthesis, control vegetative growth, and reduce nutrient consumption.
Promote root development and enhance the absorption of trace elements (such as zinc and iron).

5. Sodium Nitrophenolate
Synergistic mechanism:
Quickly activate plant cell activity and promote the absorption and transport of fertilizers.
Often combined with urea and trace element fertilizers to improve the penetration efficiency of foliar fertilizers.

6. Diethyl Aminoethyl Hexanoate, DA-6
Synergistic mechanism:
Enhance plant photosynthesis, promote carbon and nitrogen assimilation, and improve nitrogen fertilizer utilization.
Combined with potassium dihydrogen phosphate can significantly improve the absorption efficiency of phosphorus and potassium.


7. Salicylic Acid, SA and asmonic Acid, JA
Synergistic mechanism:
Induce plant disease resistance and reduce nutrient loss caused by diseases.
Regulate stomatal opening and closing to improve water and nutrient transport efficiency.

8. Gibberellins, GA3
Synergistic mechanism:
Promote stem and leaf growth, increase photosynthetic area, and indirectly increase nutrient demand.
Use with caution, excessive use will lead to leggy growth, which is not conducive to nutrient accumulation.

9. Ethephon
Energizing mechanism:
Promote fruit ripening and nutrient return, reduce fertilizer waste in the later stage.
Commonly used for ripening fruit trees in the later stage to improve the distribution efficiency of potassium fertilizer.


Application precautions
1. Concentration control: Regulators need to be used at low concentrations (ppm level), and excessive use can easily lead to pesticide damage.
2. Synergistic ratio: pH compatibility should be considered when compounding with fertilizers (such as DA-6 is suitable for mixing with acidic fertilizers).
3. Application period: Root-promoting agents (such as IBA) are recommended to be used during the basal fertilizer period, and foliar synergists (such as sodium nitrophenolate) are suitable for spraying during the topdressing period.

By rationally selecting regulators and fertilizers, fertilizer utilization can be significantly improved (reducing the dosage by 20%-30%), while enhancing crop resistance and yield. In actual application, the formula needs to be optimized according to crop type and soil conditions.