Wheat is a crop that depends heavily on foliar tissue to fill grain heads, so foliar diseases can greatly impact yield. According to The Ohio State University, the flag leaf makes up approximately 75% of the effective leaf area that contributes to grain fill. This article will help you identify the common yield-robbers in your wheat fields and manage them effectively.

 Easily identified by yellow and purple discoloration starting at the tips of the leaves.

 Barley Yellow Dwarf is a virus, so foliar fungicides are entirely ineffective. The disease is introduced to plants through the feeding activity of aphids. The best way to control the disease is to control its vector, so insecticidal seed treatments and foliar insecticide applications in the fall/early spring are effective. If you notice any number of aphids when scouting, it would be economically beneficial to treat them due to the high loss potential of Barley Yellow Dwarf.

Fusarium Head Blight/Head Scab (Impact: High)

 Pink or orange mold on the seed head. When infections are severe, heads will have a pale to almost white coloration similar to frost or hail damage.

 Apply a triazole-containing fungicide at beginning flower. Avoid fungicides that contain strobilurins, as those active ingredients can exacerbate vomitoxin levels in grain. Wheat varieties with strong genetic tolerance are highly recommended.

Stagonospora Nodorum Blotch (Impact: High)

 Less common than Fusarium Head Blight. It also doesn’t contain mycotoxins so it doesn’t have lasting grain impacts. That being said, this disease can impact kernel size and test weight. Timely fungicide applications at flag leaf and flower are effective at controlling Stagonospora.

 Small, yellow to orange blisters that form in straight lines or stripes along the leaf. Less commonly, lesions can be found on the head.

 While there can be some genetic resistance, the best form of management comes from scouting and fungicide applications

 Small, orange to brown blisters spread sporadically across leaf tissue. This disease looks very similar to common rust in corn.

 Some genetic tolerance, but foliar fungicides are the most effective option.

Foliar fungicides are effective at controlling Powdery Mildew.

 These molds appear after periods of rainfall and high humidity at or around maturity. The impact on yield is minimal, so corrective action is unnecessary.

Several factors influence a fungicide’s ability to suppress the disease, including spray coverage, timing, and disease pressure. Research has shown that Group 3 (DMI/triazole) fungicides are most effective at suppressing the disease if they are applied at early flowering or Feekes 10.5.1. If favorable conditions are present for disease development, applications can continue to be successfully made up to seven days after Feekes 10.5.1.

Beck's has taken a lot of the guesswork out of the decision with our 

 studies. When choosing a fungicide to protect against late-season wheat diseases, be sure to avoid any that contain a strobilurin, as that mode of action can exacerbate the effects of Fusarium Head Blight. The graphs below show a selection of products that are 