Q&A: Why Are We Seeing an Early Flush of Volunteer Wheat
June 29, 2012
Extension Educators Paul Hay, Randy Pryor, and Jenny Rees from southeast and south central Nebraska are working with producers who are reporting volunteer wheat in soybeans and sudex planted on wheat stubble fields. Normally hard red winter wheat would have had a fairly strong dormant stage of three to four weeks after harvest when it won't germinate. This year growers are seeing something different. What's causing this?
Stephen Baenziger, UNL wheat breeder and professor of agronomy and horticulture, responds: My guess is that you are describing wheat that was harvested this year and then followed by double cropped soybeans. It's likely the wheat line was one that can sprout easily and has a low level of dormancy. (The breeding backgrounds of some wheat lines, such as white wheat and soft wheat, don't have a strong a dormancy factor.) It also may be that the lines finished so quickly that the normal dormancy process did not complete its cycle. One way of tricking a dormant line is to harvest it early before the dormancy "sets in." Dormancy is often a late process in kernel development, so if the kernel fills very quickly, maybe dormancy did not fully develop.