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Growth regulator herbicides

I. Growth regulators (SOA 4, SOA 19)

The growth-regulator herbicides consist of synthetic auxin and auxin transport inhibitor compounds. These include

  • Phenoxy acetic acid.
  • Benzoic acid.
  • Pyridine.
  • Arylpicolinate.
  • Pyrimidine
  • Quinoline.

Growth-regulator herbicides can act at multiple sites in a plant to disrupt hormone balance and protein synthesis and thereby cause a variety of plant growth abnormalities.

Growth-regulator herbicides control broadleaf weeds, and most will injure sugarbeet. Herbicides in this group can move in the xylem and phloem to areas of new plant growth. As a result, many herbicides in this group are effective on perennial and annual broadleaf weeds.

Herbicide uptake primarily is through the foliage, but root uptake also may occur.

Auxin transport inhibitors, such as diflufenzopyr, inhibit the movement of auxinic compounds from meristematic (actively growing) cells. Thus, when combined with an auxin herbicide such as dicamba, the herbicide moves into these cells but cannot move out, resulting in greater concentrations of the auxininic herbicide within meristematic regions.

CAUTION: Mention of a pesticide or use of a pesticide label is for educational purposes only. Always follow the pesticide label directions attached to the pesticide container you are using. Be sure that the area you wish to treat is listed on the label of the pesticide you intend to use. Remember, the label is the law.

Reviewed in 2018

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