Source: Kansas State University Extension
By Steve Schuler, Executive Director, Kansas Crop Improvement Association
May rains brought on weeds and delayed wheat harvest in some areas of Kansas to the extent that herbicide applications had to be made to burn down weeds prior to harvest. Farmers intending to hold back some of their harvest for use as seed this fall should have that wheat tested for germination.
Some herbicides, such as glyphosate, are not recommended on wheat to be saved as seed. Most, if not all, of the common herbicides used as pre-harvest aids in wheat require that the grain be below 30% moisture before application. At or below this moisture content, the grain is post-physiological maturity and unlikely, or less likely, to be adversely affected. Seed germination can be greatly inhibited if pre-harvest herbicide applications are made at an improper stage of grain maturity.
The only way to be sure that germination has not been harmed by herbicide application is to have the seed tested by a professional laboratory such as Kansas Crop Improvement Association’s (KCIA’s) Seed Quality Testing Lab.
Growers may be tempted to conduct their own germination test, but home tests may not provide enough information. Whether seed germination has been harmed by a herbicide is really only part of the story. Seed germination is relatively easy to conclude from a germination test. What is not quite so obvious is the potential damage that may have been done to seed even though it appears to germinate.
The trained analysts at KCIA evaluate each seedling in a test to make sure it has all the essential structures to establish a plant in the field. The lack of roots or a damaged coleoptile resulting from a herbicide application can affect that seed’s ability to establish itself when planted.
It would be good if every grower planted Kansas-certified seed, which has been professionally cleaned and tested, but if a grower has a legal right to use saved seed, we think it is a prudent step to have that seed professionally tested.
Information on KCIA seed laboratory services can be found at www.kscrop.org/labservices.aspx or call 785-532-6118.