According to the Bible, God prevented the people of Babel from building a tower by mixing up their languages. Once they could no longer understand each other, they couldn’t work together. Likewise, if you can’t speak the same language as your agronomic consultant, it’s tougher to communicate when deciding when to spray weeds or scout for insects and diseases.

Sharp agronomists at Iowa State University in the mid-20th century realized that if soybeans were going to become a serious crop, they would need a “language” to communicate precisely with other agronomists in Missouri, Ohio and elsewhere. The staging system developed for this purpose is still used today.

“When I scout a field, I first determine stage of growth,” says Steve Gauck, a regional agronomy manager for Beck’s, sponsor of Soybean Watch ’24. “If I later find a problem like a disease or insect, it pays to know the stage of growth when looking for possible remedies. Product labels often refer to stage of growth of the crop.”

Staging helps with scouting

Gauck carries a copy of the Purdue University Corn and Soybean Field Guide in his pocket. He refers to it for help when scouting for diseases, insects and weeds, and when determining growth stages.

“When cotyledons are above the surface, that’s the VE stage,” he notes. “Unlike corn, the growing point is above the ground in the VE stage. That’s why hail or frost is less forgiving on young soybeans than young corn.”

Related:Do you have enough soybean plants?

Cotyledons expand, and then two unifoliate leaves emerge. “That’s the VC or ‘cotyledons expanded’ stage,” he explains. “Once margins of leaflets making up the first trifoliate no longer touch, it’s the V1 stage.”

The vegetative or V stages progress with theaddition of each set of trifoliate leaves, Gauck says. Tell a farmer anywhere that you are looking at a V6 plant, and he knows it has six trifoliate leaves. “The catch is that the margins of those leaves on that top set of trifoliate leaves can’t touch to count,” Gauck notes.

From the field:
Early-season challenges continue

Here is what Beck’s field agronomists are seeing in their regions:

In Minnesota. “In southern counties, many soybeans are in the unifoliate to first trifoliate stage. Early-planted soybeans are at the third and fourth trifoliate, or V3 and V4 stages. Some storms were accompanied by hail last week, which thinned some soybean stands. With all the rain and cooler temperatures this spring, we’ve seen more PPO-type, preemerge herbicide injury to soybeans. In some-early planted soybeans in the V3 to V4 stage, we’re beginning to see iron deficiency chlorosis on some soils with elevated pH levels.” — Dale Viktora

Related:Do you know soybean growth stages?

In Nebraska. “Ten days of heavy rain led to washed-out and drowned-out acres. Many were replanted in early June. Acres not affected are into the V2 through V5 stages, with nodulation underway. Warmer temperatures will likely bring new waves of weeds, so we will need dry weather to get post herbicides applied.” — Trey Stephens

In Illinois. “In east-central and northeast Illinois, most have finished planting and are focusing on completing post herbicide applications between frequent rainfall events. Some are asking how to maximize post application with foliar nutrition products. With anticipated limited nutritional uptake by root systems, my recommendations focus on products containing potassium acetate. Final tip: Remember, herbicide applications after soybeans begin to flower usually come with risk of lower yield.” — Chad Kalaher