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: Simazine damage on Japanese cherry
Photo by: R.S. Byther
  
Herbicide Damage : Triazines (atrazine, simazine and others)
(revision date: 5/1/2013)


Biology
Triazines are nonselective herbicides that are used for control of annual and perennial grasses and broadleaf weeds. These products are translocated in plants in the xylem. Older leaves show the first symptoms. On broadleaf plants, these symptoms appear as a leaf tip, marginal, or interveinal chlorosis or necrosis of leaf margins. On conifers, damage appears as needle tip chlorosis or necrosis. Damage may be more pronounced with higher temperatures. Triazine damage resembles that caused by dichlobenil (Casoron). These products can persist in the soil for most of the growing season or from one growing season to the next. Triazine damage rarely causes veinal chlorosis (yellowing of veins and adjacent tissues), which may instead be caused by long-term residual herbicides.
Management Options

Non-Chemical Management
  • Desirable plants may be damaged if drift occurs from a nearby herbicide application.
  • Carefully read all label instructions and precautions prior to purchasing and applying herbicides.
Select non-chemical management options as your first choice!

Chemical Management

Carefully read all label instructions prior to using triazine formulas.

Images

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Caption: Simazine damage on Japanese cherry
Photo by: R.S. Byther
Caption: Atrazine damage on fir
Photo by: R. Maleike
Caption: Atrazine damage on fir, spruce, and pine
Photo by: R.S. Byther