Home 5 Ag Stories Making fungicide management decisions

Making fungicide management decisions

Photo by Ben Nuelle

A Midwest seed company is advising farmers to scout fields for diseases.

Wyffels Hybrids is encouraging its customers to enter fields soon to prevent and detect the spread of plant pathogens. Brent Tharp serves as agronomy and product training manager for Wyffels Hybrids. Tharp is advising growers to search for common leaf diseases, such as Gray Leaf Spot.

“The most common ones we’re going to see in the Midwest and Iowa is Gray Leaf Spot. That has rectangular lesions that are confined in the leaf veins,” Tharp said. “There’s Northern Leaf Blight. Northern Leaf Blight has the longer, elliptical, cigar-shaped lesions. Then there’s Rust – Southern Rust and Common Rust. Southern Rust moves in later in the season versus at this time or tasseling. You can see some Common Rust, but generally it doesn’t become an economical issue.”

Lesions on the ear leaf and above should be sprayed with a fungicide application. Wyffels  encourages growers to apply fungicide applications during the “tassel application” phase, between full tassel and brown silk. Tharp also recommends growers take environmental conditions into consideration when applying fungicides.

“Instead of making a specific hybrid-by-hybrid decision, let’s make an environment decision,” Tharp said. “Choose the field that’s going to be prone to leaf diseases (corn-on-corn fields), fields with a lot of residue, and low lying fields. Generally when the fog rolls in the summer, lower lying fields are the last fields for that fog to burn off. That means moisture is staying within that canopy longer. You get moisture in the canopy, that’s what’s needed for these leaf diseases to start spreading rapidly.”

Wyffels research suggests fungicide applications provide more than a yield advantage.

“What we’ve seen in our independent agronomy research is a yield advantage. Over nine years of testing, it’s averaging out over everything. It’s averages out to 10 bushels, in our testing. You also get  improved plant health and better standability at harvest. I think that’s something that’s often overlooked, and it’s worth a lot of money. If we can buy a few weeks there at harvest and keep that crop standing, that’s worth a lot too,” Tharp said.