USDA Implements Electrophoresis Protein Testing to Distinguish Kentucky 31 from Other Tall Fescue Varieties

Date
September 17, 2024

The U.S. Department of Agriculture’s (USDA) Agricultural Marketing Service (AMS) announced today that beginning Oct. 1, it will start using a form of electrophoresis protein testing known as the Isoelectric focusing (IEF) gel method to distinguish Kentucky 31 from other tall fescue varieties for complaints under the Federal Seed Act. This new method for testing was developed after many years of parallel testing and outreach to stakeholders.

AMS conducts varietal testing on agricultural and vegetable seed to ensure truthful marketing of seed and compliance with the Federal Seed Act. Variety testing is usually conducted using the USDA Trueness-to-Variety (TTV) Field Grow-out method which uses verified samples to compare to labeled claims which can take almost a year to complete. Moving forward, AMS will test seed lots labeled as Kentucky 31 using the IEF gel method.

This method extracts protein from tall fescue seedlings grown in controlled conditions for four weeks and compares the known protein banding pattern of Kentucky 31 to tall fescue seed lots submitted for verification. Resulting patterns that match the expected Kentucky 31 pattern meet Federal Seed Act labeling requirements for the variety.

Comparison studies between the IEF gel method and the field grow-out test have found no significant differences between the tests, indicating a strong equivalency. The primary benefit of the IEF gel method is efficiency. This method takes fewer resources and 90 percent less time than the traditional field grow-out test. The TTV grow-out will serve as a secondary method.

Once the new method of testing is implemented, interstate shippers that receive a Kentucky 31 violation notice based on an IEF gel test may request a Seed Regulatory and Testing Division (SRTD) consideration for a field grow out. If approved, and a trial is conducted, the results of the field trial will be used to determine compliance status. Where field test results corroborate the IEF gel results, the interstate shipper will be responsible for the TTV costs in addition to any penalty amounts. Where field test results do not corroborate IEF gel results, the shipper will not be charged for the field tests.

Please contact AMS’s Seed Regulatory and Testing Division Director, Ernest Allen, at Ernest.Allen@USDA.gov or (704) 810-8884 for additional information and questions.

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