Adjuvants 101: Nonionic Surfactants

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Adjuvants 101: Nonionic Surfactants

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Managers of land and aquatic systems have something in common. That is, they must manage vegetation at some point during the year. Perhaps it is weedy plants in crops, unwanted plants in lakes or ponds, invasive plants on rangelands, or unwanted vegetation in forest undergrowth. For each of these instances, control of plants is the common thread.

Control of plants is most commonly accomplished with the use of herbicides with a nonionic surfactant. Spraying herbicides to control unwanted vegetation is considered to be cost and time effective. However, care must be taken in selecting the herbicide which must be able to control the unwanted plant while being relatively safe to nontargets and the environment.

In addition, it is typical for the herbicide spray to include an adjuvant that will enhance the performance of the herbicide.

  • Anionic surfactants – have a negative charge and in aqueous solutions they form anions.
    • Anionic surfactants enhance foaming and other spreading properties of a liquid and are commonly used in shampoo.
    • If anionic surfactants are used with herbicides, the spray mixture can produce excessive amounts of foam that can negatively affect spray delivery and the control of plants.
  • Ampholytic (amphoteric) surfactants –have both positive and negative charge and in aqueous solutions they are capable of forming anions and cations, depending on the pH of the solution.
    • Amphoteric surfactants are used rarely. When used, the amphoteric surfactant must match the properties of the herbicide formulation.
  • Nonionic surfactants – produce little or no ionization (no electrical charge) in water.
    • Nonionic surfactants do not have a charge in solution and are the most commonly used surfactants with herbicides.

Why are nonionic surfactants preferred for use with herbicides?

Nonionic surfactants are the most commonly used and preferred surfactant for application with many pesticides, including herbicides, growth regulators, defoliants, fungicides, and insecticides.

Features of nonionic surfactants

Nonionic surfactants:

  • Are composed of alcohols and fatty acids.
  • Have no electrical charge.
  • Remain stable in cold water.
  • Arecompatible with many herbicides.

Benefits of using nonionic surfactants with herbicides

Nonionic surfactants:

  • Do not harm plants when used properly. However, application rate is critical because when they are applied at too high a rate injury to desired plants (non-targets) may occur.
  • Reduce surface tension of the spray solution and increase coverage and wettingability of the applied spray.
  • Less costly than other types of surfactants.

Examples of nonionic surfactants from Brewer International

Further Reading

Use of Silicone Adjuvant in Agriculture

References

Bohmont, B.L. 2007. The Standard Pesticide User’s Guide – 7th Ed. Pearson Prentice Hall.

Brewer International has been a leader in land and water chemistry since the 1980’s and for over 40 years has proudly served it’s national and regional distributors.

Our products are used widely across the United States in agriculture, aquatics, forestry, rights of way, and land management.

Our customers trust our dedication to quality ingredients, tried and true formulas, and positive outcomes.

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