In order for pesticide applications to be effective,they need to cover the treated area uniformly with a desired dose.The area of coverage is determined in part by the process of evaporation and spread ofthe droplets on a leaf surface. This process varies with the type of leaf surface (hairy vs. waxy, for example) and the physical properties of the pesticide.
Nonionic surfactants are often recommended for use in formulations and tank mixtures to increase the effectiveness of foliar-applied pesticide spray treatments. Nonionic surfactants break the surface tension so pesticide droplets spread more evenly and adhere longer on leaf surfaces. Spray mixtures containing surfactants can provide better spray coverage, longer-lasting residue, better active ingredients uptake, and improved penetration of the active ingredient into leaf tissue.This can result in better efficacy, less pesticide use, and less overall cost.
Close-up videosrecorded in Dr. Heping Zhu’s lab clearly demonstrate the differences in the spread and evaporation process of a single droplet with and without surfactant on hairy and waxy leaf surfaces.