The message is being heard loud and clear by a large percentage of corn growers that early-season weed competition reduces end-of-season yield.

“I’d say 95 percent of the guys we’ve been working with in the last couple years have been using a preemergence herbicide for their corn. It hasn’t been a hard job convincing them, even the guys that are growing Roundup Ready corn,” said Harley Jones, Crop Production Services, Ferris, Ill. About 50 percent of growers in the Ferris area are growing conventional corn compared to Roundup Ready hybrids.

 “I like farmers to use a full dose of residual herbicide, not cut rates, so that they have all the horsepower in the field that they might need,” Jones said.

Some university and company research shows that if weeds are allowed to emerge with corn and are left uncontrolled while corn is growing from the V2 to V4 stage, the yield loss is usually more than one bushel per acre per day.

Early-season weed control in corn pays offThe longest lasting residual is what farmers need to keep their corn field clean early and possibly until the corn shades the row middles, quite possible with narrower planted rows.

For Jones, his residual herbicide recommendations are based on products that will last long enough so that if a farmer cannot get back into a field for a post herbicide application because of weather, then that preemergence herbicide will hold back the weeds as long as possible. Limited field work was the case in the Ferris area last year when 26 inches of rain fell in June and there was cool weather; therefore, it is important that a preemergence herbicide performs during highly variable weather.

Brian “Mac” McDaniel, Bayer, senior technical sales consultant for much of Indiana, said Corvus and its related stable mate, Capreno, effectively destroy weed competition.  “Corvus and Capreno both have root and shoot uptake, solid residual control and innovative crop safeners as well.  Weed control occurs as broadleaf weeds or grasses germinate or as they emerge. The active chemistries work well in extremely wet or dry environmental conditions. Corvus is mainly used PE or EP, and can also be used PPI, or PP, while Capreno is mainly used early postemerge,” he explained.

Jones has recommended a lot of Corvus herbicide, and growers report being highly satisfied. To develop trust with customers, he says that he airs all the pros and cons to any herbicide program to a customer, and the grower makes the ultimate decision based on back and forth discussion.

Testimonials from satisfied customers are always helpful, noted McDaniel. “When farmers have used a Corvus weed control system, they’ve seen some definite yield advantages. I’ve had guys in the last three years report yield advantages anywhere from six bushels to 26 bushels better yields per acre.” Those yields are typically between a Corvus application and two-pass programs of either two shots of glyphosate or to a short-residual preemergence followed with a post herbicide application.

Jones and McDaniel both noted that top producers don’t balk at the price of a quality herbicide program such as one with Corvus or Capreno. “They recognize that if they use a cheap cut-rate chemical program resulting in weeds in their corn, then they can lose 25, 30 to 40 bushels per acre, and they don’t want that to happen,” said Jones. 

“Growers have never had better corn genetics available, and commodity prices are looking fairly good; therefore, growers need to focus on profitability per acre as opposed to cost of production per acre,” McDaniel said.

For more information, contact McDaniel at