Managing Weeds and Pests in Conventional Corn and Soybeans Starts with a Good Chem Plan

Growing a successful, healthy crop takes good planning, whether you’ve decided to plant conventional crops (those without genetically modified traits) or seed that does have GM traits. And part of that plan should include scouting and a good chem plan in order to manage pests and weeds, and reach top yields. 

While the cost of production is often lower on conventional crops (because the seed doesn’t include costly trait technology), there are some key things to know about management and to develop an effective chemical plan for these crops. 

Here are some of the basics of creating a chem plan for conventional corn and soybeans: 

Start With A Clean Seed Bed

Both corn and soybeans should start with a clean seed bed. Tillage or an effective burndown program is a must. Burndown is also the time to apply a reliable residual herbicide, containing multiple modes of action to maintain the clean seed bed for 21-28 days post-planting. When the preplant herbicide is overlapped with another residual herbicide, in addition to a foliar herbicide to control weed escapes that have emerged, the field should remain clear until crop canopy. 

PRO TIP: Can you really grow clean crops without glyphosate? Yes, you can. 

Several troublesome weed species have shown resistance to glyphosate, including kochia, waterhemp, marestail, giant ragweed and Palmer amaranth. Glyphosate still controls most grasses and many broadleaf weeds, but so do many other herbicides, such as those containing acetochlor, atrazine or metolachlor. Besides, glyphosate and glufosinate (which has no known resistance issues) can still be applied preplant and pre-emerge in conventional corn and soybean production.

Match your herbicide selection with the field’s weed history and positive weed identification.

You can use the same herbicides that are used when growing traited corn and soybeans, except the only difference in traited crop and conventional crop herbicide programs would be the use of glyphosate or glufosinate post emergence—you can’t use these two chemistries if the crop doesn’t have the GM traits that makes them tolerant to these two herbicides.

Working All the Bugs Out

With diligent scouting and proper timing of insecticide applications, you can control insects such as European Corn Borer and Western Corn Rootworm. Prior to the introduction of Bt traits in 1996, this was the common practice. There are many choices of insecticides and methods of application to achieve acceptable insect control today, if infestations rise to economic levels. For corn rootworm, consider an in-furrow insecticide. For European Corn Borer, consider a foliar insecticide at the proper time to control the pest.

Understanding Your Crop ROI

The cost savings you can often receive from planting more affordable conventional seed can typically more than cover the costs for any additional herbicide or insecticide expenses.

The bottom line is that with proper planning, conventional corn and soybeans can be grown with good weed and insect control, just like traited corn and soybeans. And planting conventional crops can also potentially improve your overall farm profitability. 


It is a violation of federal and state/provincial law to use any crop chemical product other than in accordance with its label. The distribution, sale and use of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. It is your responsibility to confirm prior to purchase and use that a product is labeled for your specific purposes, including, but not limited to, your target crop or pest or weed, and its compatibility with other products in a tank mix.