Definition and Role of Surfactants in Herbicide Formulations

Surfactants are chemicals that decrease the surface tension of liquids dramatically. Surfactants are common adjuvants to herbicides in formulations for improved performance. Surfactants increase the wettability of water so herbicides stick better to plant leaves, and are more effective against weeds.

How Surfactants Enhance Herbicide Performance

• Wetting: Spreads herbicide uniformly on plant leaves, no slide-off.

• Dispersing: Gives the herbicide more even distribution in the spray, and has a better chance of reaching the plant.

• Penetrating: Allows the herbicide to pass through the plant's waxy cuticle into the plant body.

• Sticking: Stables the herbicide to the surface of the plants longer for greater effectiveness.

Key Benefits of Using Surfactants in Herbicide Applications

• Enhanced Herbicide Efficiency: Wetting, dispersing, and penetrating properties of herbicides are enhanced by surfactants, which enable them to hit more effectively with plants.

• Reduced Chemical Usage: Because surfactants enhance the herbicide's absorption, a smaller amount of herbicide can be required, reducing environmental impact.

• Protection of Non-Target Plants: Some surfactants are relatively safe for non-target plants like vegetables and fruits, so you can minimize damage to these plants.

• Reduced Drift and Volatility: Surfactants enhance spray adsorption and stability by suppressing herbicide drift and volatility to make the application more accurate.

Pesticide dissolution makes surfactant micelles more hydrophobic

Surfactants are essential for herbicides because they not only make herbicides effective but also help save the environment. The right type of surfactant (e.g., nonionic vs cationic) will depend on the herbicide formulation and use case. Nonionic surfactants are commonly used in agriculture and landscaping because they're broad compatible and less toxic.

The Role of Surfactants in Droplet Size and Spray Retention

Surfactants also minimize rebound and evaporation so that the droplets get distributed more evenly on the plant surface. This is good for spray uniformity and also longer lasting on the leaves. Surfactants can also make the spray performance better by modifying the droplet shape and size to allow them to pass through the capillary systems of the leaves.