Disease

Planting has been delayed for many across the region, increasing the chance of greater yield loss due to disease infecting corn and soybeans at earlier growth stages.

Experts are predicting an abundance of corn and soybean diseases in the Midwest this season due to excessive rain and cold temperature this spring. Jason Snell, agronomy service representative at Syngenta, says the delayed start moves growth stages back and lines up with disease development timings.

“Cooler temperatures and slower growing conditions can lead to longer exposure during the timeframe of those stages that are most susceptible to disease pressure,” he said.

While northern corn leaf blight has been in the Upper Midwest for some time, gray leaf spot has started to increase its presence throughout the region, becoming more and more prevalent, according to Snell.

“Both of those overwinter on residue in the soil,” Snell said. “Both could be a problem, especially earlier in the growth stages. They often infect later at the reproductive stages of corn, but with these conditions we could see earlier onset. An earlier timing of fungicide could be a better play this year.”

Snell says tar spot is something for farmers to keep an eye out for this year as well. It’s been seen in areas of Wisconsin.

“It’s a newer disease that came out of Central America and moved up over the last few years,” he said. “It’s a pretty devastating disease that can have some severe yield reductions to it. It has to be treated preventatively, so you’ll need to make sure you have your protection as soon as you see symptoms, or before, if possible.”

How did tar spot makes its way up? Snell says the early-April snow storm we experienced didn’t do farmers any favors.

“That storm blew up a lot of snow and some of it had that brown tinge to it. That tinge came from soils in western Texas. A lot of that disease inoculum moved up during that storm. We need to be aware there’s a risk of more diseases like tar spot that we’re not as familiar with. Fungicide application could be a big payoff this year.”

Snell’s big concern for soybeans this year is white mold. For farmers with a corn/soybean rotation, white mold was an issue in 2017 and is expected to be again now in 2019.

“Two years ago in 2017, there was a lot of white mold, so a lot of guys on a corn/soybean rotation had corn last year and now beans this year. The white mold inoculum can stay in the soil for 7-8 years, so if you had an issue two years ago or thought you might have, that inoculum is now in the soil.”

The R1 stage of soybeans is when farmers will start to get blossoms or flowers on their beans. White mold needs dying material on the plant, and those blossoms will perform their function on the beans before falling off. As they fall, some will get caught in the branches of the beans, and those white mold spores can then infect those blossoms and then continue onto the rest of the plant, causing severe yield reductions.

White mold is a high yield disease, attacking the “best looking” fields – ones that are the most lush, with little airflow through the canopy because they’re so vegetative.

“The exciting thing for us is we have a new fungicide for white mold this year called Miravis Neo, which contains a combination of three different fungicides (Dependent, Quadris and Tilt),” Snell explained. Dependent is carrying the weight on the mold, Tilt is a curative for other diseases and Quadris is for overall plant health. You’re getting increased plant health, as well as white mold protection. We’re really excited about this product.”

Syngenta also has Trivapro for corn, a fungicide they launched four years ago.

“There’s a nice yield response to it. You’ll see nice, long lasting results from the active ingredients: Quadris, Tilt and Solatenol. You get 40-45 days of control and a nice, consistent return on investment on those treatments. We’re happy to have this as a solution for growers,” Snell concluded.