Table 2.2-5.

Table2.2-5. Characteristics of “burndown” and postemergence corn herbicides.
Herbicide¹ Family Mode of action Site of action Systemic² Injury symptoms Weeds controlled Residual³ Potential problems
  1. See Table 2.2-1 for additional products containing these active ingrediants.
  2. Movement of herbicide from foilage to roots. Important for perennial weed activity.
  3. Residual: N = no soil activity; S = one or two weeks soil activity; M = one or two months; L = full season, may carry over under certain conditions or if misapplied. Residual activity is dependent upon rate, soil type, and environmental conditions.
2,4-D Phenoxy Growth regulator Multiple Yes Twisting of foliage, strapped leaves, brittle corn stalks, malformed b Annual broadleaves and perennials S Perennials too small, corn too large, resulting in injury
Accent (nicosulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Foxtails, shattercane, seedling and rhizome johnsongrass S-M Incorrect adjuvant, drought-stressed weeds, tolerant weeds
Aim (carfentrazone) Triazoline Cell membrane disrupter (contact) PPO No Foliar burning Annual broadleaves N Use without a surfactant, poor spray coverage
atrazine Triazine Photosynthesis inhibitor D-1 quinone protein No Foliar burning Annual broadleaves M-L Weeds too large; resistant species
Banvel / Clarity (dicamba) Benzoic acid Growth regulator Multiple Yes Twisting of foliage, leaf cupping Annual and perennial broadleaves S-M Perennials too small, drift onto nontarget plants
Basagran (bentazon) Benzothia-diazole Photosynthesis inhibitor D-1 quinone protein No Foliar burning Annual broadleaves, yellow nutsedge N Weeds too large; tolerant species; droughty weather
Basis / Resolve Q (rimsulfuron + thifensulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Small annual grasses and broadleaves S-M Incorrect adjuvant, drought-stressed weeds plus tolerant weeds; tankmi
Beacon (primisulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Annual broadleaves, shattercane, seedling and rhizome johnsongrass S-M Incorrect adjuvant, drought-stressed weeds, tolerant weeds
Buctril (bromozynil) Nitrile Photosynthesis inhibitor D-1 quinone protein No Foliar burning Annual broadleaves N Weeds too large; tolerant species, droughty weather
Callisto (mesotrione) Callistemone Pigment inhibitor HPPD enzyme Yes Chlorotic, whitened plant tissue Annual broadleaves and large crabgrass M Incorrect adjuvants; drought-stressed weeds; interactions with certain
Distinct (dicamba + diflufenzopyr) Benzoic acid + semi-carbazone Growth regulator Multiple Yes Twisting, bending, cupping of foilage Annual and perennial broadleaves S-M Perennials too small, annuals too large, drift onto nontarget plants,
Exceed (prosulfuron + primisulfuron) Sulfonylurea Amino acid biosynthesis inhibitor ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Annual broadleaves S-M Incorrect adjuvant, drought-stressed weeds
Glyphosate Amino acid derivative Amion acid biosynthesis inhibitor (protein) EPSP synthase Yes Quickly stops weed growth, gradually turn yellow and die Annual and perennial grasses and broadleaves N Perennial weed too young, poor spray pattern, high spray volume, or ap
Gramoxone (paraquat) Bipyridilium) Cell membrane disrupter (contact) Photosystem I No Foliar burning Annual broadleaves and grasses N Use without a surfactant, poor coverage
Harmony SG (thifensulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Annual broadleaves S-M Incorrect adjuvant, drought-stressed weeds, resistant species
Impact (topramezone) Triketone Pigment inhibitor HPPD enzyme Yes Chlorotic, whitened plant tissue Annual broadleaves and some grasses M Incorrect adjuvant, drought-stressed weeds, weeds too large
Laudis (tembotrione) Pyrazolone Pigment inhibitor HPPD enzyme Yes Chlorotic, whitened plant tissue Annual broadleaves and some grasses M Incorrect adjuvant, drought-stressed weeds, weeds too large
Liberty / Ignite (glufosinate) Amino acid derivative Amino acid biosynthesis inhibitor GS enzyme Somewhat Foliar burning and yellowing Annual broadleaves and some perennials N Poor coverage, large weeds, new weed flushes
Option (foramsulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Annual broadleaves S-M Incorrect adjuvant, drought-stressed weeds, resistant species
Permit (halosulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes Quickly stops weed growth, gradually turn yellow and die Annual broadleaves, yellow nutsedge S-M Incorrect adjuvant, drought-stressed weeds, tolerant weeds, tank-mix f
Resource (flumiclorac) N-phenyl-phthalimide derivative Cell membrane disrupter (contact) PPO No Foliar burning Annual broadleaves N Temporary crop injury, poor coverage, droughty weather, weeds too larg
Sencor (metribuzin) Triazine Photosynthesis inhibitor D-1 quinone protein No Foliar burning Annual broadleaves M Weeds too large; resistant species
Stinger (clopyralid) Pyridine Growth regulator Multiple Yes Twisting of foliage, leaf cupping Annual broadleaves, thistles S-M Perennials too small, corn too large, resulting in injury