Test Overview
Duration: Typically 6-7 days
Herbicide bioassays are used to determine the percentage of a seed lot that expresses tolerance to a specific herbicide. They are commonly used to evaluate genetic purity by identifying plants that do not express the expected herbicide tolerance.
Herbicide bioassays may also be used to detect unexpected herbicide tolerance; however, immunoassay or PCR testing is generally recommended when the primary objective is to determine whether seeds are free of biotech traits.
Test Details
Seeds or seedlings are exposed to a specific herbicide under controlled conditions. Depending on the crop and herbicide, seeds may be germinated on a substrate containing herbicide, soaked in herbicide solution prior to planting, or seedlings may be treated after emergence.
Following treatment, seedlings are evaluated for characteristic herbicide injury. Seedlings expressing the appropriate tolerance continue to develop normally, while susceptible seedlings exhibit symptoms associated with the herbicide treatment.
Results are reported as the percentage of seedlings expressing the expected response.
Sample Requirements
Please submit a minimum of 500 seeds for most herbicide bioassays. A 400-seed test is typically conducted.
Sample requirements may vary depending on the crop, herbicide, or testing objective. Additional seed may be required when multiple tests are requested on the same sample.