When I talk to seed producers about genetic purity testing of their corn seed lots, I occasionally get a response similar to this: “How can I afford to do all of that testing?” My response is: “Can you afford not to do this testing?”
I ask them to consider the value of the seed they have produced – it is usually worth hundreds of thousands, or even millions, of dollars. An accurate and effective genetic purity test can be completed for a couple of hundred dollars within a few weeks. A good test can tell the producer whether or not the lot is correctly identified, if the hybrid pedigree is accurate, if selfing has occurred, if outcrossing is present within the lot and if any seed mixing has occurred during seed harvesting or plant operations.
Discovery of any problems related to the seed’s genetic quality is critical to the seed producer as it provides the information essential to knowing if the product is suitable for sale. Even if the news is not what the producer wants to hear, it will provide crucial data needed to make decisions regarding if the lot should be resized, blended, wholesaled or if it should be discarded.
Testing for genetic purity can occur when the seed is still in bulk storage or later when the seed is bagged in a finished condition. The important factor, regardless of the stage of processing, is that all seed sizes should be tested for genetic purity. Genetic quality can vary greatly based on seed size. Fertilization occurs at different positions on the ear throughout the pollination period. Even if the seed field was flooded with pollen during the early portion, pollen flow could decline or even cease at the end of the pollination period when the silks from the tips of the ears are receptive, magnifying the potential for foreign pollen contamination for small flat and small round seed sizes. Therefore, testing all of the seed sizes from a field is very important.
Saving some dollars in testing costs and not properly identifying the purity of your seed lots can end up costing you big in the end if your genetic quality is poor and your customers are unhappy with the appearance and performance of your hybrids on their farms.