Table 2.2-5. Characteristics of “burndown” and postemergence corn herbicides.

Table2.2-5. Characteristics of “burndown” and postemergence corn herbicides.
Herbicide1 Family Mode
of
action		 Site
of
action		 Systemic2
  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
Accent (nicosulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes
Aim (carfentrazone) Triazolinone Cell membrane PPO disruptor (contact) No
atrazine Triazine Photosynthesis inhibitor D-1 quinone protein No
Banvel/Clarity (dicamba) Benzoic acid Growth regulator Multiple Yes
Basagran (bentazon) Benzothia-diazole Photosynthesis inhibitor D-1 quinone protein No
Basis (rimsulfuron + thifensulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes
Beacon (primisulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes
Buctril (bromoxynil) Nitrile Photosynthesis inhibitor D-1 quinone protein No
Callisto (mesotrione) Callistemone Pigment inhibitor HPPD enzyme Yes
Distinct (dicamba + diflufenzopyr) Benzoic acid + semi-carbazone Growth regulator Multiple Yes
Exceed (prosulfuron + primisulfuron) Sulfonylurea Amino acid biosynthesis inhibitor ALS synthase Yes
Glyphosate Amino acid derivative Amino acid biosynthesis inhibitor (protein) EPSP synthase Yes
Gramoxone (paraquat) Bipyridilium Cell membrane disrupter (contact) Photosystem I No
Harmony GT (thifensulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes
Liberty (glufosinate) Amino acid derivative Amino acid biosynthesis inhibitor GS enzyme Somewhat
Option (foramsulfuron) Sulfonylurea Amino acid biosynthesis inhibitor (protein) ALS synthase Yes
Permit (halosulfuron) Sulfonylurea Amino acid biosynthesis inhibitor ALS synthase Yes
Resource (flumiclorac) N-phenylphthalimide derivative Cell membrane disrupter (contact) PPO No
Sencor (metribuzin) Triazine Photosynthesis inhibitor D-1 quinone protein No
Stinger (clopyralid) Pyridine Growth regulator Multiple Yes
Tough (pyridate) Pyridazine Photosynthesis inhibitor D-1 quinone protein No
Impact (topramezone) Triketone Pigment inhibitor HPPD-enzyme Yes
Table2.2-5. Characteristics of “burndown” and postemergence corn herbicides. (cont.)
Herbicide1 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 Twisting of foliage, strapped leaves, brittle corn stalks, malformed brace roots Annual broadleaves and perennials S Perennials too small, corn too large, resulting in injury
Accent (nicosulfuron) 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) Foliar burning Annual broadleaves N Use without a surfactant, poor spray coverage
atrazine Foliar burning Annual broadleaves M-L Weeds too large; resistant species
Banvel/Clarity (dicamba) Twisting of foliage, leaf cupping Annual and perennial broadleaves S-M Perennials too small, drift onto nontarget plants
Basagran (bentazon) Foliar burning Annual broadleaves, yellow nutsedge N Weeds too large; tolerant species; droughty weather
Basis (rimsulfuron + thifensulfuron) Quickly stops weed growth, gradually turn yellow and die Small annual grasses and broadleaves S-M Incorrect adjuvant, drought-stressed weeds plus tolerant weeds; tank-mix for lambsquarters control
Beacon (primisulfuron) 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 (bromoxynil) Foliar burning Annual broadleaves N Weeds too large; tolerant species, droughty weather
Callisto (mesotrione) Chlorotic, whitened plant tissue Annual broadleaves and large crabgrass M Incorrect adjuvants; drought-stressed weeds; interactions with certain OP insecticides will cause crop injury
Distinct (dicamba + diflufenzopyr) Twisting, bending, cupping of foliage Annual and perennial broadleaves S-M Perennials too small, annuals too large, drift onto nontarget plants, tank contamination
Exceed (prosulfuron + primisulfuron) Quickly stops weed growth, gradually turn yellow and die Annual broadleaves S-M Incorrect adjuvant, drought-stressed weeds
Glyphosate 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 application with contact or photosynthetic inhibitor herbicide
Gramoxone (paraquat) Foliar burning Annual broadleaves and grasses N Use without a surfactant, poor coverage
Harmony GT (thifensulfuron) Quickly stops weed growth, gradually turn yellow and die Annual broadleaves S-M Incorrect adjuvant, drought-stressed weeds, resistant species
Liberty (glufosinate) Foliar burning and yellowing Annual broadleaves and some perennials N Poor coverage, large weeds, new weed flushes
Option (foramsulfuron) Quickly stops weed growth, gradually turn yellow and die Annual broadleaves S-M Incorrect adjuvant, drought-stressed weeds, resistant species
Permit (halosulfuron) Quickly stops weed growth, gradually turn yellow and die Annual broadleaves, yellow nutsedge S-M Incorrect adjuvant, drought-stressed weeds, tolerant weeds; tank-mix for lambsquarters control
Resource (flumiclorac) Foliar burning Annual broadleaves N Temporary crop injury, poor coverage, droughty weather, weeds too large, tolerant weeds
Sencor (metribuzin) Foliar burning Annual broadleaves M Weeds too large; resistant species
Stinger (clopyralid) Twisting of foliage, leaf cupping Annual broadleaves, thistles S-M Perennials too small, corn too large, resulting in injury
Tough (pyridate) Chlorosis, Foliar burning, stunting Annual broadleaves, yellow nutsedge N Tolerant species, weeds too large
Impact (topramezone) Cholortic, whitened plant tissue Annual broadleaves and some grasses M Incorrect adjuvant, drought-stressed weeds, weeds too large