Surfactants are specialized adjuvants used in agricultural production that reduce surface tension, allowing liquids to better penetrate surfaces. Adding surfactants to crop formulations can improve efficiency and help conserve irrigation water by reducing runoff.
Depending on the application of the agrochemical formulation, the choice of surfactant is particularly important. Different surfactants can act as wetting agents, dispersants, emulsifiers, or thickeners. Wetting agents are primarily used as adjuvants in various crop treatments, while dispersants, thickeners, and emulsifiers are often used to provide stability to agricultural input formulations.
Next,we will introduce several common surfactants:Tea Saponin , Soya Bean Lecithin ,Xanthan Gum.
1. Tea Saponin
Tea saponin is a natural glycoside compound extracted from the seeds of the Theaceae plants (such as Camellia oleifera). It is an excellent natural surfactant (biopesticide adjuvant) and biopesticide itself.
Function: Tea saponin exhibits excellent wetting, spreading, and penetrating properties. Adding it to insecticides, fungicides, or foliar fertilizers significantly reduces the surface tension of the solution, making it easier to spread and adhere to the surface of plants or pests, preventing it from being washed away by rain. It also promotes the penetration and absorption of active ingredients, thereby increasing the efficacy of the pesticide and fertilizer and reducing the use of chemical pesticides by approximately 30%.
Advantages: Naturally biodegradable and environmentally friendly, it reduces the risk of pesticide damage associated with traditional chemical adjuvants (such as silicones).
2.Soya Bean Lecithin
Soya Bean Lecithin is a natural amphoteric surfactant found widely in plants and animals, primarily extracted from soybeans or egg yolks. In agriculture, it serves as an excellent adjuvant and biostimulant.
Function: Similar to tea saponins, Soya Bean Lecithin reduces surface tension, enhancing the adhesion, spread, and penetration of pesticides or fertilizers onto leaves. Its unique amphiphilic structure enables it to effectively emulsify oily ingredients, helping active substances disperse evenly and penetrate the leaf cuticle, increasing their utilization rate.
Advantages: As a component of biological cell membranes, it is safe for plants and easily degraded.
3. Xanthan Gum
Xanthan gum is a microbial polysaccharide produced by fermentation of Xanthomonas campestris. It is a highly effective water-soluble thickener and stabilizer. In agriculture, it is primarily used as a processing improver in formulations.
Functions:
- Suspension stability: In suspension concentrate (SC) pesticides, xanthan gum significantly increases the viscosity of the system, effectively preventing the settling and agglomeration of insoluble solid particles, ensuring uniform composition throughout the product’s shelf life and accurate dosage during use.
- Emulsion stability: In systems such as emulsions in water (EW), it helps stabilize the oil-water interface and prevent emulsion separation.
- Sustained-release effect: Its high viscosity slows the release rate of the pesticide’s active ingredients, extending its effective duration.
- Anti-drift: During spraying, it increases droplet size, reduces the drift of fine droplets, improves target deposition, and reduces environmental pollution.
Advantages: Low dosage (typically 0.1%-0.3% is sufficient for effectiveness), high efficacy, acid, alkali, and salt resistance, good compatibility, and biodegradability.
Key comparison summary of the three surfactants
Application Prospects: All three are excellent representatives of “green agricultural materials.” In practical applications, they are often used in combination to achieve synergistic effects. For example:A highly effective biopesticide might contain: tea saponin (as a penetrant and active ingredient), lecithin (as a co-emulsifier and biostimulant), and xanthan gum (as a thickener to prevent sedimentation).This combination concept represents the future development trend of agricultural inputs: high efficiency, safety, and environmental friendliness.