What is the mechanism of action of agricultural silicon synergists in foliar absorption

Agricultural silicone synergists are specialized adjuvants designed to enhance the foliar absorption efficiency of pesticides and nutrients. Their primary components are often organosilicon compounds with excellent surface activity and penetration properties. Widely applied in modern agriculture, these synergists play key roles in foliar fertilization, pesticide efficacy enhancement, and crop stress resistance. The core function of silicone synergists is to improve the spreading and penetration of spray solutions on leaf surfaces, thereby increasing the uptake and utilization efficiency of active ingredients.

Reduction of Surface Tension and Enhanced Spreading

Plant leaves are naturally coated with a waxy cuticle, creating high hydrophobicity and surface tension, which limits uniform distribution of water-based pesticides and nutrient solutions. Silicone synergists contain both hydrophilic and hydrophobic groups in their molecular structure, significantly reducing the surface tension of spray solutions. Lower surface tension allows droplets to spread over a larger area, improving coverage and preventing runoff or droplet aggregation. Increased contact surface enhances the opportunity for active ingredients to be absorbed by leaf tissue.

Formation of Liquid Films and Penetration Enhancement

Silicone synergists form stable micro-thin liquid films on leaf surfaces, extending the retention time of active ingredients. These films maintain moisture and reduce evaporation, providing a continuous medium for diffusion of pesticide molecules. The liquid film allows physical adsorption and penetration of active ingredients into the cuticle, especially near micro-pores and stomata. By improving wettability and flow characteristics of the solution, silicone synergists facilitate movement of the active compounds into leaf tissues, significantly enhancing foliar absorption efficiency.

Molecular Penetration and Cell Wall Transport

Silicone synergist molecules exhibit intrinsic membrane-penetrating abilities that assist active ingredients in crossing cuticle and cell wall barriers. Hydrophobic portions interact with the waxy cuticle, while hydrophilic parts stabilize the solution, creating molecular-level penetration channels. Active ingredients follow these pathways into epidermal cells and mesophyll tissues, resulting in more efficient absorption. The synergistic effect of molecular penetration and surface activity accelerates the translocation of active ingredients within leaf tissues.

Stability of Active Ingredients and Degradation Protection

Silicone synergists enhance the stability of pesticides during foliar absorption. The liquid film and molecular encapsulation reduce degradation caused by sunlight, temperature, and oxidation. Extended retention time on the leaf surface and microenvironment protection in the film slow down decomposition, increasing both absorption and efficacy. This stabilization not only boosts foliar uptake but also strengthens crop protection and nutrient efficiency.

Stomatal Uptake and Systemic Translocation

By lowering droplet surface tension and improving wettability, silicone synergists increase the likelihood of active ingredients entering stomata. Stomata are essential pathways for foliar absorption and transpiration regulation. The liquid film around stomata facilitates penetration into mesophyll cells, where active compounds can be translocated through phloem and xylem, achieving systemic distribution across the plant. Enhanced stomatal uptake accelerates plant response to foliar applications, making synergist effects more pronounced.

Environmental Adaptability and Efficacy Benefits

Silicone synergists demonstrate strong adaptability under various environmental conditions. In high temperature, drought, or windy conditions, film stability and surface activity maintain foliar absorption efficiency. Their benefits extend beyond pesticide absorption, improving foliar fertilization and micronutrient utilization. Continuous use can reduce pesticide dosage, enhance crop stress resistance, and improve both yield and quality.