Powdery mildew beginning to appear on wheat

Diane Brown-Rytlewski, Michigan State University Extension, Department of Plant Pathology -

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.

Powdery mildew is beginning to show up on wheat in Michigan. Wheat is currently at Feekes 5 around Isabella County, and at Feekes 6-7 (first to second node) for most other parts of the state. It is not uncommon to see powdery mildew low in the canopy, early in the season. Current temperatures are in the favorable range (around 59-72°F) for this disease. Often, mildew stays low in the canopy and does not cause significant loss to yield. Powdery mildew is more of a concern if it continues to climb and gets up on the flag leaf. If you are seeing it now, continue to monitor your fields and evaluate the level of infection at flag leaf to the boot stage. In general, the threshold for fungicide treatment is two to three powdery mildew spots per leaf on the leaf just below the flag leaf, (averaged over 30-50 leaves sampled randomly in the field).

 In the April 26 Field Crop CAT Alert, Management of foliar wheat disease, Part 2, is a rating table of fungicides evaluated for effectiveness against powdery mildew, and the growth stage limitations for applying certain fungicides. You can check the MSU variety trials ratings (http://www.css.msu.edu/varietytrials/) to get an idea of how your variety performed in statewide university trials, and use your own field experience with a variety to determine how susceptible it is to mildew. The variety trial ratings for powdery mildew are scored from 0-9, with (0 the lowest amount of mildew, to 9 the highest) There is a yearly, two year, and three year average score. Looking at the average rating over several years will give you a better idea of performance than looking at a single year.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).

Did you find this article useful?

You Might Also Be Interested In

Tag List
  • field crops,
  • msu extension,
  • wheat
  • follow us on youtube
  • follow us on linkedin
Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).