By Bill Curran, Weed Scientist; Dwight Lingenfelter, Program Development Specialist

As the soybean crops continue to mature, volunteer corn is rearing its head in some fields. We assume that most of the volunteer corn is glyphosate- and glufosinate-resistant, so we will not spend time going over all the options for killing the various types of volunteer corn. 

In general, the most logical choices to control volunteer corn in any kind of soybean are the post-grass herbicides (e.g., Assure II, Select, clethodim, Fusilade, etc.). Below are some rates to consider depending on the height of the volunteer corn.

Always include the necessary adjuvants, otherwise control will be impacted. In most cases, this will require the addition of a crop oil concentrate (COC) or methylated seed oil (MSO). If crop injury is a concern, a nonionic surfactant (NIS) may be used in place of an oil with Select Max only. 

Keep in mind if you plan to tank-mix a broadleaf-specific herbicide, the rate of the grass herbicide may need to be increased to overcome possible antagonism.

Product Volunteer Corn Height Rate per acre
Select Max 0.97EC Less than 12 inches 6 fluid ounces
  12-24 inches 9 fluid ounces
Clethodim 2EC 4-12 inches 4 fluid ounces
  12-18 inches 6 fluid ounces
Assure II/Targa 0.88EC 10-12 inches 4 fluid ounces
  12-18 inches 5 fluid ounces
  18-30 inches 8 fluid ounces
Fusilade DX 2EC Less than 12 inches 4 fluid ounces
  12-18 inches 6 fluid ounces