Tall Fescue Online Monograph

Herbicide family

Common name

Characteristics of the herbicide family

Amide

(acetanilide)

Isoxaben, Napropamide

Interfere with protein and chlorophyll production; inhibit the elongation of roots and also may disrupt plant cell membranes; primarily absorbed by emerging shoots; translocated upward in xylem; moderately water soluble; not held strongly by soil organic matter.

Dinitroaniline

Benefin,

Benefin + Oryzalin, Benefin + Trifluralin, Pendulum, Prodiamine

Disrupt the normal separation of chromosomes; strongly inhibit rooting of sensitive plants; herbicide injury often results in plants with thick, stubby roots and few secondary roots; primarily absorbed by shoots as they move upward in soil; much of the uptake by broadleaf weed seedlings occurs by way of roots; are yellow in color due to chromorphic nitro chemical groups; noncorrosive; low water solubility; require rainfall or irrigation following application for activation and to minimize volatilization and photodecomposition; strongly adsorbed by clay and organic matter.

Oxadiazole

Oxadiazon

Inhibit an enzyme involved in the formation of chlorophyll; light is necessary for herbicide activation in plants; strongly adsorbed by organic matter and soil colloids; do not leach; rainfall or irrigation is necessary to incorporate oxadiazon in soil; the herbicide is noncorrosive.

Pyridine

Dithiopyr

Inhibit the division of plant cells; herbicide selectivity is similar to that of the dinitroanilines with activity on a wider range of annual broadleaf weeds; do not leach in most soils.

Substituted urea

Siduron

Primarily absorbed by roots of developing seedlings; upwardly mobile in xylem; unlike most substituted urea herbicides, siduron does not inhibit photosynthesis by blocking electron transport; siduron disrupts mitosis and damages roots of sensitive seedlings.

Sulfonamide

Bensulide

Absorbed by roots of emerging seedlings; inhibit root growth of sensitive seedlings by disrupting cells as they enlarge; no foliar uptake; completely metabolized to carbon dioxide in resistant plants; readily adsorbed by organic matter; not prone to leaching; rate of breakdown in soils increases as soil temperature and organic matter content increase.

Unclassified

Ethofumesate

Developing seedlings primarily absorb ethofumesate through shoots; epicuticular wax deposition on leaves of sensitive seedlings decreases, which may enhance foliar uptake of several postemergence herbicides.