They say, "Climate is what we expect, weather is what we get." While the author of that catchphrase is up for debate, there is no denying extreme weather struck in 2024. In the Missouri Bootheel and surrounding areas, drought hit first. Then hurricanes came, and farmers felt every bit of it the first half of harvest as they watched soybean quality diminish.
Of course, we cannot control environmental factors. But is it possible for farmers to get ahead of quality loss when heavy rains are forecasted? Justin Calhoun, state cropping systems specialist at the University of Missouri, shared his observations from the field and gave recommendations.
Can you plan for harvest in a hurricane?
Early planted soybeans can increase yield potential. With that, fungicide applications at the R3 growth stage have become a popular practice in recent years to prevent foliar disease and protect yield in the early planted crop.
This R3 fungicide application, as Calhoun explained, causes soybean plants to remain green longer and hang onto leaves. Thus, from the roadside, a field might appear too early to cut; however, those pods and seed moisture may be dry enough to harvest.
From his observation, that is what happened this year in late September just before Hurricane Helene rolled through. "Before that hurricane, we had a lot of fields that guys drove by and thought they were still too green to cut. So, they waited until after the hurricane," Calhoun said. "In reality, those beans were probably 14% to 16% moisture and could have been cut before the hurricane."
To avoid this scenario in the future, he stressed the importance of moisture testing at harvest when an intense rainfall event is forecasted. Calhoun said, "My biggest recommendation to growers is to pull some samples, get them threshed out, and do a moisture test to make that decision about harvest."
Desiccate with caution
At the harvest stage, desiccating soybeans is common, to speed up the dry-down process. This begs the question: Should a farmer desiccate a soybean field to get the beans out when a hurricane is on the way?
While Calhoun supports this practice, he recommends making the decision with a great deal of caution. It depends on crop maturity, the method of desiccation, and if the weather forecast gives you enough time.
"The danger is, if you desiccate before the beans are far enough along physiologically. If we shoot that desiccation application to those beans too early, we are going to hurt quality just as bad as if we would have left it to the weather," he said.
One product often used for desiccation is Gramoxone, a group-22 herbicide with the active ingredient paraquat. There are other product options. Whatever you choose, Calhoun said it is important to check the label for the preharvest interval (or how many days after the application you must wait before soybean harvest).
The preharvest interval for Gramoxone is 15 days. Given that timeframe, it is hard to get an application out and harvest soybeans before hurricane rains. Another desiccation option is Sharpen, a group-14 herbicide with the active ingredient saflufenacil. It is more expensive, but the preharvest interval for Sharpen is only three days.
Calhoun said, "If the beans are far enough along physiologically, and we are in a dire situation with a hurricane coming, a desiccation product with a shorter preharvest interval would likely be the best option."
Research on soybean quality
Soybean planting date and quality are environmentally dependent. Going forward, Calhoun plans to continue research efforts on soybean planting dates. Plus, quality testing is now part of his study.
He said, "We were fortunate that seed quality was included as part of our early planting research this year, and we have those issues captured in data. It takes multiple years of research and data to be confident in any of our findings.
"We are going to continue to press on, taking into account all that information to provide the best recommendations moving forward."
