Full explanation
Mechanism: surfactant contains hydrophilic and lipophilic parts, allowing droplets to flatten across the waxy leaf — coverage jumps from 15–30% to 60–90%. For sulfonylureas (Granstar, Express), efficacy drops 30–50% without a surfactant. Silicone surfactants (SilWet L-77, Silwet Gold) are 1000× more potent than standard ones, delivering 100% coverage at 0.05–0.1% concentration — but can cross leaf barriers and cause phytotoxicity. Doses: non-ionic 0.1–0.25% of working solution (100–250 mL per 100 L water), silicone 0.05–0.1%. Price: UAH 80–250/L, i.e. UAH 10–30/ha tank-mix share. Important: don't use a surfactant with products that already include one (Axial, Actellic) — doubling up reduces efficacy through over-coverage and run-off.