Herbicide Injury Symptomology: Seedling Growth Inhibitor Injury

Dinitroanalines, Chloroacetamides and Thiophenamines, and Thiocarbamates

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smDinitroanilines3 (7937 bytes) smDinitroanilines1 (13484 bytes) smDinitroanilines2 (4883 bytes)

Trade Names and Uses:

  • Balan (Benefin)
  • Prowl (Pendimethalin)
    -corn, soybeans, grain sorghum
  • Sonalan (Ethalfluralin)
  • Treflan/Tri-4 (Trifluralin)
    -soybeans, grain sorghum

Mode of Action: Mitotic disruptor, which inhibits cell division and the formation of lateral roots through inhibition of tubulin protein synthesis.

Injury Symptoms: Soil activity, which can cause late emergence, and stunted plants that do not fully emerge from the soil and have short, thick lateral roots with swollen root tips. Grass shoots are short and thick, may appear red or purple in color, and look drought stressed. Broadleaf plants may have swollen hypocotyls, and may have rough, crumbled leaves. Following preemergence treatments, callus tissue may appear at the base of soybean stems.

Chloroacetamides and Thiophenamines

smDuall (10043 bytes) smHarnessc (13286 bytes)

Trade Names and Uses:

  • Dual (Metolachlor)
    -soybeans, corn, grain sorghum
  • Frontier (Dimethanamide)
    -soybeans, corn, grain sorghum
  • Harness/Topnotch/Surpass (Acetochlor)
  • Lasso/Partner/Microtech (Alachlor)
    -soybeans, corn, grain sorghum

Mode of Action: Seedling root and shoot inhibitor - specific sites unknown, but thought to interfere with lipid synthesis.

Injury Symptoms: Causes terminal inhibition, and in broadleaves can cause heart-shaped leaves due to midvein inhibition, rough, crinkled leaves and possible leaf cupping. Grasses will show stunted or malformed shoots and may have tight leaf rolls. The stunting of shoots may result in abnormal seedlings that do not fully emerge from soil causing grasses to leaf out underground and leaves may not properly unfurl.


smEptams (18449 bytes) smEradic(13209 bytes)

Trade Names and Uses:

  • Eptam (EPTC)
    -corn, alfalfa
  • Sutan (Butylate)
  • Far-Go (Triallate)

Mode of Action: Seedling root and shoot inhibitor, specific sites unknown.

Injury Symptoms: Soil activity, which can lead to inhibition of growth of meristematic regions, enlarged cotyledons, leaf malformation (onion leaf) and crinkling, thickened dark green leaf tissue, delayed seedling emergence, stunting of shoots and poor emergence from the soil. Grasses may fail to emerge from the coleoptile or leaf out underground. Leaf tips may not unfurl from the coleoptile properly which results in the buggy-whip effect. Broadleaves may have puckered leaves or leaf buds may not open.

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