On the herbicide label you are holding is a statement, “add a wetting agent to improve the effectiveness” of the product. What exactly is a “wetting agent?”
A wetting agent or herbicide surfactant is a product that enhances the herbicide it is added to. Surfactants do not harm plants or weeds by themselves. They are added to herbicides to create a product that penetrates the waxy surface of the leaves and stems. It is a material that causes the herbicides to become more soluble and easier for the plant to take in and utilize. By doing this, the surfactant allows more of the active ingredient of the herbicide to be used by the plant; causing the plant to be effected much more rapidly than it would be without the surfactant.
A nonionic surfactant should only be used when one is applying the product on emergent vegetation like Cattails or on submerged vegetation close to the surface of the water like Duckweed. This is due to the nature of surfactants tending to “stick” to vegetation or develop a thin film on the surface of the water. It does not sink into water well, so if one is targeting deeper submerged aquatic weeds, it would actually defeat the purpose of the product by adding the aquatic surfactant to the spray solution.
When using a product like Catt Plex, it is extremely helpful to add a nonionic surfactant, such as Plex Mate, to the spray solution, since all target species are emergent and the solution would be made more effective with the addition of the surfactant. Be sure to only add a minimal amount of surfactant, as most surfactants can cause foam to develop on top of the spray solution.
When using a product like Tsunami DQ, the use of a nonionic surfactant would be discouraged since most target weeds are submerged and the surfactant could suspend the herbicide on the water’s surface. One should only use Plex Mate with Tsunami DQ when treating emergent vegetation or floating leaf pond weeds like American Pond Weed or Duckweed.
So, wetting agents or nonionic surfactants are very effective in penetrating leaf surfaces of emergent vegetation such as cattails, grasses, sedges. However, they tend to make treating submerged vegetation treatments less effective.
For more information about our nonionic surfactant, contact Sanco.