Changing management practices impacts soybean growth

SEYMOUR, Ill. — Understanding the environment of a field can help farmers choose the best soybean variety, as well as make management decisions.

“Organic matter, slope, elevation all have influence on water,” said Greg Ury, BASF business development representative.

“We have multiple subfield environments — there are places in a field that are wet and places that are dry,” said Ury during a presentation at a BASF Field Day, held at the BASF Midwest Research Farm in Seymour.

“We want to understand not just which variety wins in a plot for that year, but we want to understand the environmental component,” he said. “We know that branch yield is more susceptible to stress and loss of pods and flowering when we get into water limited environments.”

BASF is doing population trials across four states that include about 600 comparisons.

“In this data set, it tells us lowering populations costs yield,” Ury said.

“We do most of our trials on better acres, so when we get into environments that hold water, lower populations make sense,” he said. “We were able to hold onto the yield on the branches.”

However, the results are different for water-limited areas.

“If I had 100,000 population and it was a water-limited acre, I was giving up three-quarters of a bushel for every 10,000 less seeds I was putting out there,” Ury said.

BASF planted a trial with 60,000 population that had a final stand of 50,000.

“If we had the right environment and variety, we had 95-bushel beans,” Ury said. “I don’t recommend that because it was a nightmare for weed control and the risk is if we have a water-limited environment.”

Trials show that all soybean varieties branch more at low population and branch less at higher population.

“We found we can’t go as low on population with varieties that are going to be more main stem,” the BASF representative said.

“Because we put ourselves at a risk of not being able to capture yield, but we also don’t have as much of a yield gap when we get into that water-limited environment.”

Varieties that are typically main stem might not win plots in a year when everything is going well, Ury said.

“But when we get into field environments with more variability, they are more stable across fields, as well as from year to year,” he said.

BASF also evaluates fungicides.

“On average we get 4.5- to 5-bushel response to fungicides in our trials and that’s looking at hundreds and hundreds of trials,” Ury said.

“But when we look at it by population, we’ve seen the greatest response when we have varieties that put a lot of yield on branches at low populations and we have drought,” he said.

If a farmer planted 140,000 seeds but ends up with 90,000, those plants are going to have more light and they will put more branch yield on.

“I hear people say, I don’t have a great stand so I don’t want to spend money on fungicides,” Ury said. “But that’s probably the greatest response you’re going to get so I would not give up on those fields.”

Destructive Threat

“Soybean cyst nematode, whether you see it or don’t see it in fields, robs on average $1 to $1.5 billion from us every year,” said Colin Rogers, BASF seed agronomist for Illinois. “SCN is tricky because we really can’t visualize it until it comes in later in the season and our options to treat are pretty limited.”

When SCN-resistant soybean varieties were launched with PI 88788, Rogers said, there was about a 4% yield loss between optimal conditions and what it controlled because this trait does not control 100% of SCN.

“Because we kept continually using this trait, 10 years later, there’s now a 9% yield gap,” he said. “By 2028, we’re looking at 13% of the yield on the table so we need to look at how to get that back into our grain bins.”

In the central part of Illinois, Rogers said, typically there is a 2.5% loss from SCN.

“We have hot pockets with 5% to 8% loss,” he said. “Two-percent loss doesn’t sound like a lot, but with 85- to 90-bushel yields, we’re giving up two to three bushels.”

There have been no new innovations or technologies since 2000 to help farmers manage SCN, but that will change in 2028.

“In 2028, we will launch the BASF-developed Nemasphere trait to the marketplace,” Rogers said.

“With Nemasphere, we’re talking about getting on average 8% yield back in soybean cyst nematode fields or in this area 2.5% to 3%,” he said. “That’s $20 to $30 back into farmers’ pockets.”

Nemasphere will have a regulatory requirement to be stacked with a native trait.

“By doing that, there will be no refuge in a bag,” the seed agronomist said.

“We’re going to have Nemasphere in other people’s bags, as well, because we think this is a technology that needs to be on everybody’s fields,” Rogers said.

“Nemasphere pays us back in three different ways; it doesn’t just control soybean cyst nematode,” he said. “It will protect the plant from SDS because SDS enters plants through the same injuries that cysts put into the roots and it will protect soybeans from HPPD carryover.”

Looking towards the future, Rogers said, BASF is planning more introductions.

“In the 2030s, our new PPO trait is coming to the market and it will be stacked with Nemasphere to have more options for better weed control,” the seed agronomist said.

“When we get to the late 2030s, we have a new chemistry coming out and the beans will be traited to match that chemistry,” he said. “The chemistry is very effective and we’re excited about it.”