If you harvested late last fall and some stalks were already falling over, you likely left some corn in the field. If you don't believe it, walk your cornfield. For what we've seen, ears of corn here and there shouldn't be too hard to find. That could mean volunteer corn to contend with if you're coming back with soybeans in that field.
The trick is that if it was Roundup Ready corn last year, the volunteer corn will likely be glyphosate-resistant. Since Liberty Link is stacked in some glyphosate hybrids, it may also be resistant to Liberty. So what can you do to control it?
The first thing is to watch for it and not let it get out of hand, weed control experts say. Volunteer corn can hurt yield like any other weed, and competition begins earlier than you might think.
Travis Legleiter, Purdue University weed control specialist, says there are several options for control of volunteer corn postemergence in soybeans if you suspect the volunteer corn is glyphosate and/or Liberty resistant.
Choices for GMO volunteer corn control include dethodim products, such as Select, sethoxydim products like Poast, fluazifop products such as Fusilade and quizalifop products like Assure. You can work with your chemical supplier to see which if these products he carries, and which has performed best in your area in the past. You will also want to read labels to see if anything else should be applied with the product, and to make sure you apply the recommended label rate.
If you apply earlier rather than later, you have the best chance of excellent control, Legleiter says. If the volunteer corn has size, use the highest-labeled rate for the product of your choice when you make the application. Also note recommendations on nozzle selection and spray pressure for the application.
If the corn was not Liberty Link resistant, then Liberty would be another option. However, make sure you understand and discuss with your seedsman what traits the previous corn crop contained before deciding how to take out volunteer corn.