Small Grain Seed Quality Concerns and Options for Substandard Seed

By Jochum Wiersma, Extension agronomist

The minimum acceptable germination rate for registered and certified classes of seed of wheat, barley, oats, and rye is 85%. The ragdoll test, using seeds not treated with fungicidal seed treatment, is used to determine the official germination rate that will be reported on the seed tag.

The Minnesota Crop Improvement Association does not expect the problems to be so severe and widespread that there will be a shortage of quality seed for this upcoming season. Nevertheless, I suspect that there are plenty of individual seed lots that will not meet the minimum acceptable germination rate of 85% despite rigorous cleaning/conditioning given the problems we encountered with Fusarium head blight and preharvest sprouting.  The same will be true for farm-saved seed.

If the seed lot is to be sold as either a certified or registered class of seed, the tag will have to list not only the actual germination rate but also the word ‘substandard’. That, however, does not answer the question of how to use the seed. After all, seed treatments are touted to protect the young seedling from soil and seed-borne diseases, including Fusarium crown rot.

When you conduct the ragdoll germination test, kernels that carry viable Fusarium spores will more often than not yield damaged seedlings that will not be counted towards the reported germination rate.  Treating the same lot with a seed treatment prior to determining the germination rate will invariably result in a substantial increase the germination rate. The ragdoll test is not your field and the question in turn becomes which germination rate you should use to calculate your seeding rate to ensure you start out the season with the initial stand that allows you to maximize grain yield.

Hans Kandel and I tried to answer this question with some research in the nineties.  The long and the short of the research was that:

• The seed treatments used improved the germination rate in the ragdoll test but did not improve the initial stand.
• The results of the ragdoll test with untreated seed needed to be used to calculate the seeding rate to achieve the intended initial stand

It should be noted that the conditions immediately after seeding in the years the research was conducted were average (meaning cool) and did not favor the development of seedling blight/Fusarium crown rot, which thrives when seedbed conditions are warm and dry.  Other researchers have found that when conditions do favor seedling blight and Fusarium crown rot seed treatment did improve the initial stand.