Herbicide Injury Symptomology: Cell Membrane Disruptor Injury

Bipyridiliums, Diphenylethers, Iso-urazole, N-phenylpthalimides, and Triazolinones

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Bipyridiliums

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Trade Name and Uses:

  • Gramoxone Extra (Paraquat)
    -noncropland, soybeans and corn (as a directed spray)

Mode of Action
Disrupts cell permeability (membranes) by producing free radicals, activated by sunlight.

Injury Symptomology
Foliar activity - activated by light and causes foliar burn at site of droplet deposition. Plant leaves will have a limp, water-soaked appearance, followed by browning (necrosis) of plant tissue. Drift injury will appear as speckling on leaf tissue.

Diphenylethers

Trade Name and Uses:

  • Blazer/Status (Aciflurofen)
    -soybeans
  • Cobra (Lactofen)
    -soybeans
  • Reflex/Flexstar (Fomesafen)
    -soybeans

Mode of Action
Inhibition of protoporphyrinogen oxidase

Injury Symptomology
Mostly foliar activity - browning and necrosis of leaf tissue. Reddish brown spotting on the leaf surface may appear shortly after the herbicide is applied. Susceptable plant leaves will yellow and then turn brown and die. Plants that do not die may be stunted for a week or more. COC and other additives, as well as extremely cool or warm temperatures may increase plant injury.

Diphenylethers on Corn

smBlazerc.GIF (17098 bytes) smOdds&Ends12.GIF (6047 bytes) smDiphenylethers3.GIF (11796 bytes) smOdds&Ends14.GIF (7292 bytes)

Diphenylethers on Soybean

smDiphenylethers2.GIF (11868 bytes)smDiphenylethers1.GIF (7065 bytes) smDiphenylethers4.GIF (7679 bytes)

Iso-urazole

Trade Name and Uses:

  • Action (Fluthiacet-methyl)
    -corn, soybeans

Mode of Action
Inhibition of protoporphyrinogen oxidase

Injury Symptoms
Mostly foliar activity - browning and necrosis of leaf tissue. Reddish brown spotting on the leaf surface may appear shortly after the herbicide is applied. Susceptable plant leaves will yellow and then turn brown and die. Plants that do not die may be stunted for a week or more. COC and other additives, as well as extremely cool or warm temperatures may increase plant injury.

N-phenylpthalimides

smN-phenylpthlaimides1 (9014 bytes) smN-phenylpthlaimides3 (13954 bytes) smN-phenylpthlaimides2 (5939 bytes)

Trade Name and Uses:

  • Resource (Flumiclorac-pentyl)
    -corn, soybeans

Mode of Action
Inhibition of protoporphyrinogen oxidase

Injury Symptoms
Mostly foliar activity - browning and necrosis of leaf tissue. Reddish brown spotting on the leaf surface may appear shortly after the herbicide is applied. Susceptable plant leaves will yellow and then turn brown and die. Plants that do not die may be stunted for a week or more. COC and other additives, as well as extremely cool or warm temperatures may increase plant injury.

Triazolinones

Triazolinones on Soybeans

smTriazolinones1 (8198 bytes) smTriazolinones2 (10401 bytes)

Trade Name and Uses:

  • Authority (Sulfentrazone)
    -soybeans, tobacco

Mode of Action
Inhibition of protoporphryinogen oxidase

Injury Symptomology
Soil and foliar activity - browning and necrosis of leaf tissue. Plant leaves will show interveinal chlorosis and then turn brown and die. Reddish brown spotting on the leaf surface may appear shortly after the herbicide is applied. Plants that do not die may be stunted for a week or more. Extremely cool temperatures and/or wet soils may increase plant injury.

Triazolinones on Corn

smTriazolinones4 (11082 bytes) smAuthorc (13975 bytes) smTriazolinones3 (12110 bytes)

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