Controlling Volunteer Corn In Soybeans

Jul 04, 2014

Postemergence grass herbicides offer control of volunteer corn.

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/acre
Select Max 0.97EC	<12 inches	6 fl oz
	12-24 inches	9 fl oz
Clethodim 2EC	4-12 inches	4 fl oz
	12-18 inches	6 fl oz
Assure II/Targa 0.88EC	10-12 inches	4 fl oz
	12-18 inches	5 fl oz
	18-30 inches	8 fl oz
Fusilade DX 2EC	<12 inches	4 fl oz
	12-18 inches	6 fl oz

Source : psu.edu

Video: Sclerotinia and Lygus in Seed Canola: Field Update with George Lubberts, CCA | Enchant, Alberta

Join Certified Crop Advisor George Lubberts for this Prairie Certified Crop Advisor (Prairie CCA) field update from Enchant, Alberta. In this 12th video of the series, George takes us into a seed canola field where the male rows have been removed and the female plants are filling pods. This video was taken in the third week of August 2025.

George discusses the early signs of sclerotinia stem rot, explaining how infection begins in the stem, impacts pod development, and leads to premature ripening. He also shares insights on lygus bug management, including timing of spray applications to minimize feeding damage and maintain seed size and quality.

With cool, damp summer conditions, George notes that while disease pressure is present, overall field health remains good. The crop is just beginning to show early seed colour change, signaling progress toward maturity.

Topics Covered:

•Sclerotinia stem rot identification and impact

•Managing lygus bugs in seed canola

•Crop stage and seed colour change observations

•Timing insecticide sprays for optimal protection

•Insights from a CCA field perspective in southern Alberta