Disease
The online tool from the SCN Coalition is free and easy to use. It’s backed by research done on more than 25,000 university soybean research plots across the U.S.
Now’s the time to start making notes of tar spot pressure, field by field and hybrid by hybrid, says Missy Bauer, Farm Journal field agronomist.
Some farmers in central Illinois are making yield estimates of 250 to 270 bushels per acre. Ken Ferrie says in many of those cases a more realistic estimate, though disappointing, would be in the 170 to 220 range.
Corteva Agriscience introduces Viatude and LumiTreo to address tough disease issues and protect soybean yield potential. Both will be available for use in 2024. There are limited supplies of Viatude this season, as well.
Conditions are right for the disease to break loose in parts of the Midwest. If it does, agronomists recommend three steps farmers can take to prioritize affected cornfields for harvest to minimize yield loss.
Corn growers in 13 states have confirmed tar spot outbreaks now. Iowa leads the pack with the disease reported in at least 36 counties. Indiana is a close second. “It’s starting to explode,” one agronomist says.
Farmers can use humidity charts for their area to assess when the disease could hit their corn crop as well as the optimum time to make a fungicide application, says Missy Bauer, Farm Journal Associate Field Agronomist.
In Bob Lindeman’s soybean rows, planting populations are on a general decline, and the reduction is not about saving dollars up front, but on combatting mold and rot.
“This is the earliest we’ve reported tar spot in Iowa,” says Robertson, Iowa State professor of plant pathology. She says the early detection could be due to the Tarspotter app. Here’s how it works.
Double-digit yield losses are not uncommon. To date, 14 Illinois counties have confirmed the disease, and it’s being scouted for elsewhere by seed company and Extension pathologists and agronomists.