The growth regulators include phenoxy acetic acids, benzoic acids, and the pyridines. 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 can injure sugar-beet.
Herbicides in this group can move in both the xylem and the 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 is primarily through the foliage but root uptake may also occur 1. All phenoxy acetic acids produce identical symptoms in sugarbeet. New leaf growth generally will resume at about six to 10 days after exposure to phenoxy acetic acids.