What is a surfactant and what is it for?

A surfactant is a compound added to herbicide spray mixture to modify the liquid’s physical properties, primarily by reducing its surface tension. These substances are classified as adjuvants, materials added to enhance pesticide performance or alter the spray solution’s characteristics. The primary role of a surfactant is to ensure the active ingredients effectively contact and enter the target weed plant. Without surfactants, many herbicide applications would be significantly less effective, leading to less reliable weed control.

That being said, it is important to use the surfactant if your chemical calls for it. Surfactant is fairly inexpensive and really needed. You pay a lot of money to buy expensive herbicides and therefore you should follow the directions that they call for.

Some chemicals already have a surfactant added to the container. I would use extra if you can. If you are mixing up a gallon, it only takes about a half ounce of surfactant. That means that a quart of surfactant goes a long way.

Other adjuvants used are defoamers and dye. The defoamer prevents foaming that can cause the loss of accurate pesticide rates through spillover during mix agitation and eliminate the regeneration of foam during field applications. The sprayer dye is added to help you see where you have already sprayed, making less waste.

When these products are used correctly, not only do you save money, they help the chemical work better. As Always, read the label.

(Mitzi Thomas owns Minden Farm & Garden LLC. Watch for her column on Fridays in Webster Parish Journal. Email Mitzi questions at  mitzithomas40@yahoo.com.)

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