We’ve battled pigweed resistance since I was a kid,” says Gary Burton, a southwest Arkansas grower who has weed management at the top of his soybean production checklist.
He helps counter the weed problem with a good soybean rotation that includes corn, wheat and cotton, and a herbicide program that incorporates multiple modes of action.
Gary farms near Bradley, Ark., with his brother, Ricky, and two cousins, Rodney and Dennis Burton, operating a highly diversified program that also includes poultry.
“We have shifted more from cotton to grain,” he says, “but we try to maintain a good cotton program to help keep our local gin in operation. We try not to grow any crop more than two years in a row.”
Their 2013 rotation was full season soybeans, wheat doubled-cropped with soybeans, corn and cotton. “Again, there’s no set rotation,” Gary says. “But we know most types of rotation will benefit all crops involved.”
About one-third of the soybeans are under irrigation, while all corn and cotton are irrigated from pivots or polypipe systems. Located near the Red River, wells are 60 feet to 75 feet deep and normally provide sufficient water.
In good years, full-season soybean yields are in the 50 bushel to 60 bushel range. He pushes for a wheat bean yield near 30 bushels, following wheat that yields up to 70 bushels to 75 bushels.
A target yield for cotton is near 1,200 pounds per acre. If weather cooperates, corn yields can average 180 to 190 bushels.
Weed control is likely the Burtons’ biggest overall challenge, and pigweed is Public Enemy No. 1.
“Everyone is taking pigweed very seriously,” Gary says. “Glyphosate made everyone a good farmer when it came out. But we’ve learned that different chemistries must be used. We’ve been able to manage pigweed — the best way to control it is to not let it go to seed.
“Our diversified rotation certainly helps, and we also rotate our herbicide chemistries. As a last resort, we get out in the field and hoe out any escapes. More escapes may be seen in wheat double-crop beans.
“In-season weed control is usually good in corn. But at the end of the year, we can have some pigweed escapes come up. They make so many seed, it’s hard to get them all. Hopefully, new chemistries like 2,4-D-tolerant soybeans will come along.”
Rotation also helps control diseases. “We have light disease pressure,” Gary says. “We apply Headline fungicide on irrigated soybeans and a generic fungicide on dryland beans. We try to plant newer wheat varieties and treat about one-third of the acres, which helps manage disease problems.”
University of Arkansas plant pathologists monitor numerous fields across the region for disease pressure.
“We’re fortunate to have a good group of Extension and research people in our region to help catch diseases in soybeans or other crops if they do occur,” Gary says.
Mississippi State University notes that fungicide seed treatments may increase emergence of lower quality seed, especially under less-than-ideal soil conditions. Seed with 80 percent or higher germination may be affected slightly, if at all.
MSU says a fungicide containing the active ingredient metalaxyl may prove beneficial for early planting. Seed treatments with fungicides may increase stands, but rarely increase yields as long as final stands are uniform and within the desired range.
Cropping history, soil temperatures and the five-day weather forecast following planting will all aid in this decision.
Gary plants soybean varieties in maturity groups ranging from the high 4s to mid-5s. Much of the South also uses that type maturity selection. His soybean plant population is in the 135,000 to 140,000 seeds per acre range.
MSU Extension notes that plant population can affect optimal yield potential and economic net returns, as well as negative factors such as potential for lodging.
Additional factors that may influence final plant populations include soil condition at planting, type of planting equipment (planter or drill), percent germination of seed, and in some cases, seed vigor. Choosing a seeding rate should be based on factors such as desired plant population, soil type, planting date, and maturity group.
Gary counts on crop consultant Steve Schutz, Shreveport, La., to help scout for insect and disease problems. Stink bugs can always be an insect to reckon with, along with velvetbean caterpillars.
“We have to watch for insects on some of our corn as well,” he says. “About 50 percent is Bt corn and half is non-Bt. A seed treatment usually handles the pests. But we have to watch for late season stink bugs in spots.”
Overall, the soybean, corn, cotton and wheat rotation helps boost all production, Gary says. “The rotation is essential in our weed, insect and disease management. There are too many factors that can hurt yields — we must do all we can to help our bottom line.”