Corn Herbicide Traits

Corn Herbicide Traits

Seeds arranged in bioassay. Pink seeds at front are check seeds.

Seeds arranged in bioassay. Pink seeds at front are check seeds.


Herbicide Bioassay – Used for trait confirmation on 400 seeds. Seeds imbibe herbicide solution over a seven-day test. Each tray positive and negative trait check seeds planted to ensure accurate rate of herbicide has been applied.

Adventitious Presence (AP) or (Unintended presence) percent- Used to determine if GMO free seed is contaminated. A herbicide bioassay on 400-2400 seeds is utilized. Each tray contains positive and negative trait check seeds used to demonstrate an accurate rate of herbicide and non-tolerance symptoms.

Seedling Spray Over – Two hundred corn seeds are grown to the two leaf stage and then sprayed using a DeVries Track Sprayer. Positive and negative check references are used and test is evaluated 7-10 days after herbicide application. 

Glyphosate and Glufosinate herbicides are utilized in testing.

What is Reported

For the herbicide bioassay the percentage of normal, abnormal, dead and trait seedlings are reported.

In the AP test,  the percentage of trait seedlings is reported.

Seedling Spray over includes the normal and trait percentage.

Value of Results

Trait confirmation of herbicide tolerance is required by the trait license provider. Adventitious Presence (AP) testing detects the presence of unintended traits, alerting seed owner to potential concerns in end use markets. 

Seedling spray over test emulates applications to seedling when seed imbibition of the herbicide active ingredient may not be providing satisfactory results. 

Agronomically Accurate Seed Testing Results

SoDak Lab's goal is to deliver fast, accurate, and diagnostic seed testing services.