Planning to use saved seed next year for planting? If you used glyphosate as a harvest aid last year, you’d better reconsider.
Used properly, glyphosate is a terrific product. In recent years, however, our seed lab has seen an increase in samples with poor germination that has been attributed to the use of glyphosate as a harvest aid. We have seen numerous examples in many crops including wheat, durum, flax, lentils and field peas.
For several years, the department has been educating seed growers that glyphosate should not be used on seed crops. Manufacturers warn against its use on seed crops and that information is published in the NDSU Weed Control Guide every year. We are unsure whether there is a lack of awareness of the problem or if people are simply willing to take the risk. Regardless, continued educational efforts on our part are needed.
In case you doubt what you have read or heard, here are 98 reasons why you shouldn’t use glyphosate on a seed crop. The picture below shows the affect of glyphosate on field peas. This sample had a germination score of 2%. 98% were abnormal.
More importantly, if you performed a “home germination test” and saw results like this, you might think that seed was good. Wrong! All of the seed pictured at right are abnormal. Abnormal seedlings will not produce a viable, productive plant because they are lacking essential plant parts.
The Association of Official Seed Analysts (AOSA) Training Manual defines an abnormal seedling as one that does not have all the essential structures or is damaged, deformed or decayed to such an extent that normal development is prevented.
In dicotyledonous plants such as field peas, essential structures include the primary root, secondary roots, cotyledon and epicotyl (stem, scale leaf and primary leaf). One can easily see that the seedlings in the photo are abnormal compared to the diagram on the right. None of the seedlings shown have a normal stem or root.
If you have relied on “home tests” in the past, we strongly recommend testing seed at an approved seed lab, staffed with professional seed analysts, to accurately determine the quality of seed. The cost of a germination test is inexpensive compared to lost revenues caused by inadequate stands due to poor seed.
Don’t use grain harvested from fields treated with glyphosate as a harvest aid for seed. It’s grain, not seed. Better yet, plant North Dakota Certified Seed that has been field inspected and lab tested to ensure it meets quality standards.