Assessing Chemical Injury in Plants

It is a good time to remember that not all plant injuries are caused by pathogens like viruses, bacteria, or fungi. Some symptoms are caused by abiotic (non-living or environmental) factors, including herbicides.

Herbicide damage can be challenging to diagnose because many of the symptoms may look like those caused by biotic factors (pathogens). Symptoms are varied and depend on several factors, including the type and amount of herbicide, source (spray, soil, grass clipping, hay, compost), location of the symptoms on the plant, and more.

The Iowa State Plant and Insect Diagnostic Clinic does NOT test for herbicide residue in plants; we can, however, help you investigate if a pathogen is causing the symptoms.

For more information on identifying, preventing, and managing herbicide damage, check out this encyclopedia article: Understanding and preventing herbicide injury.

Other resources:

Suspected herbicide damage on Fir.


Suspected herbicide damage on Amur Maple


Lina Rodriguez Salamanca Extension Plant Pathologist and Diagnostician

Dr. Lina Rodriguez-Salamanca is a diagnostician and extension plant pathologist with the Iowa State University Plant and Insect Diagnostic Clinic  (, a member of the National Plant Diagnostic Network (NPDN, ...

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