WSU Extension

Hortsense

Herbicide Damage
 
2,4-D and triclopyr 
Dicamba 
Dichlobenil (Casoron) 
Fluazifop 
Glyphosate and sulfonylureas 
Horticultural spray oil 
Long-term residual herbicides 
Triazines (atrazine, simazine and others) 



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Caption: 2,4-D herbicide damage on tomato
Photo by: R.S. Byther
  
Herbicide Damage : 2,4-D and triclopyr
(revision date: 5/1/2013)


Biology
2,4-D and triclopyr are hormone-type herbicides used to control annual and perennial broadleaf weeds. These products are translocated throughout the plant in both xylem and phloem. They mimic natural hormones in plants and primarily cause symptoms on new growth. Damage may appear as distorted plant parts including cupped leaves, strap-like leaves, and twisted new growth. Severity of damage most commonly depends on amount applied, species of plant, stage of growth, and if other herbicides are present in the mixture. Damage also may occur from drift of the pesticide or pesticide vapors. Eruptions or blisters of dead tissue may result from 2,4-D on London plane tree. Some grasses may also be sensitive to damage. Triclopyr can persist in the soil for most of the growing season or from one growing season to the next.
Management Options

Non-Chemical Management
  • Avoid applications where root uptake or drift can occur on neighboring desirable plants.
Select non-chemical management options as your first choice!

Chemical Management

Carefully read all label instructions prior to using products containing 2,4-D and/or triclopyr.

Images

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Caption: 2,4-D herbicide damage on tomato
Photo by: R.S. Byther
Caption: 2,4-D healthy and damaged phloem
Photo by: R. Maleike
Caption: 2,4-D herbicide damage on privet
Photo by: R. Maleike
Caption: 2,4-D herbicide damage on rose
Photo by: R.S. Byther
Caption: Triclopyr damage on English laurel
Photo by: R.S. Byther
Caption: Triclopyr damage on grape
Photo by: R.S. Byther
Caption: 2,4-D herbicide damage on dahlia
Photo by: R.S. Byther
Caption: 2,4-D herbicide damage on grape
Photo by: R.S. Byther