The Varietal Identification Test and the Purity Test are often confused by clients when selecting their testing needs. Here’s how to tell the difference:
VARIETAL ID VERSUS PHYSICAL PURITY
If you need to establish the actual variety of a seed sample, the Varietal Identification test (VID) is the test you want. Originally developed by the Canadian Grain Commission, the VID test individually analyzes a minimum of 7 kernels of durum, wheat or barley according to certain markers in their DNA. When the information from these markers is put together, this creates a genetic fingerprint comparable to a “barcode”. Each variety generates a distinct fingerprint that, much like a barcode differentiates Gala and Spartan apples, will differentiate AC Bellatrix from CDC Falcon. Varietal declaration is most commonly required by malting companies as a seed quality control measure. The VID test also effectively takes on the role that KVD used to play in class declaration required at the point of sale. This test is sometimes referred to by other industry professionals as “Varietal Purity”, which can cause some confusion when choosing the correct test.
If you require a test that will identify the number of contaminating crops and weed seeds that are present in a seed lot, then you need to choose the Purity Test (PUR). This is referred to as a “physical purity”, as the analyst will take a representative sample and physically look through all of the seeds present, removing the species that are not labeled on the submitted bag. These seeds are identified, classified, and reported according to the Grade Table that applies. The purity test is one of the accredited test components in establishing grade.
If there are any doubts as to which test you might require, please call the lab and speak to one of our professionals, who will be pleased to help you in selecting the test that is right for you!