The answer depends on the traits in the volunteer crop and the existing stand of corn.
a. Scenario 1: Volunteer corn is conventional. Existing crop is either Roundup Ready, Liberty Link, or Clearfield. Glyphosate, Liberty, or Lightning will control conventional corn, as long as the existing crop is either Roundup Ready, Liberty Link, or Clearfield. Liberty tends to be less effective than either glyphosate or Lightning at controlling volunteer corn.
b. Scenario 2: Volunteer corn is conventional, and existing crop is conventional. Inter-row cultivation is the only option, as long as the volunteer corn is between the rows of existing corn.
c. Scenario 3: Volunteer corn is Roundup Ready. Herbicide control options include Liberty Link corn sprayed with Liberty herbicide and Clearfield corn sprayed with Lightning.
d. Scenario 4: Volunteer corn is Liberty Link. Herbicide control options include Roundup Ready corn sprayed with glyphosate or Clearfield corn sprayed with Lightning.
e. Scenario 5: Volunteer corn is Clearfield. Herbicide options include Roundup Ready corn sprayed with glyphosate or Liberty Link corn sprayed with Liberty.
If volunteer corn is a persistent problem, some management options that might minimize the problem in the future include select hybrids that can be harvested early, no-tillage conditions, select hybrids that stand well at harvest.
If a severe volunteer corn problem is anticipated, rotate to another crop or delay planting and apply a burndown herbicide to emerged volunteer corn.
