It is wrong to assume that any product that lowers the surface tension of water or increases the wetability of a spray solution can be used as a surfactant. For example, such products as household soaps and detergents can combine with hard water to form precipitant or scum that will interfere with the performance of spray equipment. Agricultural surfactants do not form precipitants, and tire equally effective in hard and soft water as well as cold or warm water. Nonionic surfactants, do not form an overall charge. While amphoteric surfactauts may or may not form a charge depending on the acidity of the spray solution.
Nonionic surfactants are the type usually sold for adding to herbicide spray solutions.
These surfactants are good dispersing agents. Cationic surfactants can be toxic to plants and are not generally used with herbicides. Anionic surfactants have good foaming abilities and are often blended with nonionics to provide the wetting and emulsifying properties of a herbicide formulation. Crop Oils Crop oils and crop oil concentrates. However, crop oils keep the leaf surface moist longer than water, allowing more time for the herbicide to penetrate, and thus, increasing the amount of herbicide that will enter the plant.