wheat scab
© social_buttons

Heavy rain the past month, particularly in Southern Illinois, has wheat growers on high alert for an outbreak of fusarium head blight (FHB), commonly known as scab.

Steve Stallman, a wheat grower from Chester in Randolph County and president of the Illinois Wheat Association, last week contracted for aerial applications of fungicide on his wheat fields.

"We have the perfect conditions for a widespread outbreak of scab and disease problems," Stallman said. "I'm going to do whatever I can to protect my crop."

Most of Southern Illinois at the end of April was listed as having medium to high risk of FHB, according to the FHB online risk assessment tool, Carl Bradley, University of Illinois Extension plant pathologist, reported.

Fungicides most effective against FHB and the associated mycotoxin deoxynivalenol (DON) are Caramba, Prosaro, Folicur, and other tebuconazole products, according to Bradley.

"For fields that will be flowering this week, a foliar fungicide suppression of FHB and DON is recommended for fields in the medium-to high-risk areas," Bradley said. "FHB can cause both yield and quality losses."

Stallman last week estimated about half his crop was headed out. And his farm the past three weeks received more than a foot of rainfall.

"That's a real concern right now," he said. "The ground is super-saturated."

The majority of the wheat crop in Illinois as of last week remained in good to excellent condition. The crop the first of last week was rated 54 percent good to excellent, 36 percent fair, and 10 percent poor or very poor, the National Agricultural Statistics Service Illinois field office reported.

"Nitrogen was applied in good time (this spring) and the wheat right now looks very good," Stallman said. "But it all boils down to if we can get the head to pollinate and fill out. We're at a very critical point in the growing season."

Foliar fungicides are the only in-season control option for FHB and DON. However, one of the best management practices for the disease is to choose wheat varieties with a moderate level of FHB resistance, Bradley added.