Jennifer Vanderwell is a wheat breeder for Syngenta. The breeding station she works out of in Indiana is located between Ft. Wayne and Monroeville in eastern Allen County. From there, she oversees breeding for lines that wind up in Ohio, Michigan, southern Illinois, Indiana and other parts of the eastern U.S. She works primarily on soft red winter wheat, but also on white wheat.
Visiting her in her plots recently, planted only 10 days earlier, she made a striking observation. Heaving of wheat plants, like heaving of alfalfa plants, during freeze-and-thaw cycles in the winter to late winter can expose crowns to damage. For wheat, if the crown is frozen, that not only the central plant dies, but all tillers attached to that crown die. A good share of wheat yield comes from heads produced by tillers. It's one of the things that sets wheat apart from corn, even though both are in the grass family.
"We could have had considerable damage this past late winter and early spring because there was quite a bit of heaving," she says. Temperatures in the 60s during the day and freezing at night in February contributed to heaving, or moving up of the crown slowly through physical processes in the soil.
"The reason we didn't see much damage is because it was mild after that," she notes. "That's why we didn't see much damage from heaving for the 2011-12 crop."
That may not be the case for the 2012-13 crop, however. It all depends on weather conditions. First, there must be conditions that are right for heaving to occur. If the seed is planted shallow at all, say less than an inch deep, it is more subject to heaving.
Then it's a matter of the weather that occurs after the crown is exposed because of heaving of the wheat crop. A severe cold snap at that stage could result in considerable winterkill, she notes.