Dry weather challenges soybeans

LONDON MILLS, Ill. — Will 2020 be the year that soybeans show strong performance again?

Maybe — but the odds are stacked against this year’s Illinois soybean crop in many areas and the state’s 2020 crop may not see 2019 outcomes.

“Last year ended up being a very pleasant surprise from a yield standpoint. We planted beans really late, and they were really good for a lot of people,” said Lance Tarochione, DEKALB Asgrow technical agronomist for western and west-central Illinois.

But this year, while soybean planting was much earlier in many parts of the state than it was in 2019, farmers might not see the same results.

“This year, we’ve been drier during August, for sure, and some places were more blessed than others. I hope we are happy with our soybean yields,” Tarochione said.

While Illinois soybeans missed the damaging part of the Aug. 10 derecho that swept across the Midwest, from western Iowa to western Ohio, the rain that accompanied the storm was needed.

“From a crop standpoint, we were fortunate to miss the brunt of that windstorm. We had probably 60 mile per hour winds. If it had been earlier in the season or later in the season, it would have done more damage. If there is ever a good time to have a windstorm, that was about it,” Tarochione said.

One of the major stories going forward through August and toward harvest is moisture — and lack thereof.

“I think the soybean crop is under a fair amount of stress in the dry areas and would really have benefited from some good, widespread, August rainfall. If you received good rains at the end of July, that will help carry you through a dry August — to an extent. But there’s a limit to that,” Tarochione said.

The nature of those late July rains also meant that much of that moisture didn’t stick around.

“Some of those late July rains were 4-, 5-, 6-inch rains, really hard, fast July rains and half of it ran off. You just can’t store it up the way you’d like to,” Tarochione said.

That lack of rainfall may have trimmed the topside potential from soybean yields throughout the state.

“I think some areas are not going to have the crop that they had the potential to have. Not saying it’s going to be bad, it’s just not what it could have been,” Tarochione said.

He noted that lack of rainfall at the right time impacts soybean yields in a few different ways.

“The pods on the upper part of the plant don’t fill as good. You’ll see more aborted pods. You’ll see more blooms that don’t make a pod. You’ll have more pods that have one and two beans in them instead of three and four. You’ll see a lot of aborted seeds. If you haven’t had much rain in August, you are really not going to make the most out of filling those later pods,” he said.

While soybeans in Illinois may be struggling now, their start was promising — for a while.

“We got off to what seemed like a perfect start, lots of good opportunities for planting beans in April, ideal soil conditions. It was cool, but we had good soil moisture and a lot of April planting opportunities for beans. Then it turned up cold and it turned up wet and those beans grew very, very slowly. It took forever for a lot of them to get up and get going,” Tarochione said.

The good news with the dry conditions is that disease pressure appears to be low in many areas.

“We’ve had relatively low disease pressure. In the areas that have been wet, we are starting to see a lot of sudden death in some fields. That is fairly common, so it’s not a big surprise. We’ve probably had more sudden death this year than we did last year,” Tarochione said.

Other common soybean diseases appear to be lighter this year.

“I have not seen a lot of frogeye yet. Frogeye gets talked about a lot. I don’t think we have had the right kind of weather patterns here lately for frogeye. It doesn’t appear to be a bad white mold year. I think we were warm enough and dry enough that white mold is probably not going to be a huge issue. I have seen some late phytophthora in some areas where we had some of the big rains. Phytophthora is not a new pathogen, but one that has been getting worse in recent years,” Tarochione said. He noted that the latest Asgrow products provide enhanced protection against top soybean diseases, including phytophthora, white mold and iron deficiency chlorosis.

When it comes to harvesting soybeans, Illinois farmers may prioritize corn over their soybeans, but Tarochione said the key to maximizing soybean yields at harvest is keeping an eye on moisture.

“Maximizing soybean yields is really no different than corn. Timely harvest at an ideal harvest moisture is how you get the best yield out of your soybeans,” he said.

That moisture should be close to market moisture.

“The yield will be best if you cut them at 13%, 14%, 15% moisture, just real close to that market moisture. If you are harvesting beans at 8% or 9% moisture, you get a lot more shatter loss. You are losing yield just because of the water weight you’ve lost,” Tarochione said.

This column was contributed by Illinois AgriNews for Asgrow.