Tips for controlling weeds in your sweet corn

South Dakota State University Extension
Certain steps need to be taken before choosing an herbicide to control weeds in sweet corn.

Sweet corn is popular among producers and gardeners and grown across South Dakota. When growing sweet corn on a large scale, weed control can be challenging. Physical, hand weeding may be unrealistic, and research has found tillage leads to unhealthy soil systems that may increase weed pressure in the future.

Several herbicides are labeled for sweet corn production, which can be the easiest and most cost-friendly method. Certain steps need to be taken before choosing an herbicide to control weeds in sweet corn. Identifying weeds that are present in the field, knowledge about soil type and hybrid-herbicide interaction can play a vital role in properly controlling weeds in a sweet corn field. Also, crop rotation or a subsequent crop that will be grown in the field will have an impact on what herbicide is selected for the weed control.

Sweet corn hybrids vary in their tolerance of herbicides. Super sweet hybrids are commonly more susceptible to damage from sulfonylurea herbicides, like Pursuit and Accent Q. If residual herbicide is a concern, then contact herbicides are the best option for both pre and post-emergent. For post-emergent, make sure the sweet corn hybrid has the technology to resist the application of an herbicide like glyphosate (Roundup Ready 2 Technology sweet corn hybrids). If non-GMO sweet corn hybrids are planted, then post-applied herbicide options are limited. There are more pre-emergent herbicides available in sweet corn than post-emergent. Thus, it is more feasible to use a quality pre-emergent product.

A few of the pre-emergent/burndown sweet corn options are Atrazine, Acuron, Acuron Flexi, Harness, Harness Xtra, Armezon, Armezon PRO, Anthem Maxx, Bicep Lite II Magnum and Zidua. If weed issues are present after emergence, there still are a few options. Depending upon hybrid, Accent Q and Laudis can provide good post-emergent control of grasses and broadleaves. For post-emergent, broadleaf-only control, there are many options in sweet corn and some of those are Anthem products, Callisto, Laudis and Starane.