Managing Powdery Mildew
Farmers have several options to manage powdery mildew in wheat, ranging from seed treatments, variety selection, scouting, cultural practices and fungicide applications.
Using the correct fungicide seed treatment and rate is one way to provide effective and economical disease control in wheat production. Seed treatments protect seed and young plants from disease and other threats to plant health and yield. Areas commonly infested with powdery mildew also will need a foliar fungicide treatment to provide protection beyond the seedling growth stage.
Every commercially available wheat variety has a unique disease package, and excellent disease resistance is not available to manage all disease threats in high-yielding varieties. It’s best to select two or three high-yielding varieties that offer the best resistance to common diseases found on your individual farm.
When scouting for weeds and insects, check for the presence of powdery mildew and other leaf diseases. Scouting helps you make the best decision about whether or not a fungicide application is needed, and it also provides information to help you select appropriate disease management practices for future crops. If you suspect powdery mildew, take samples and work with your county Extension agent to confirm a diagnosis. Crop identification guides are also helpful.
Crop rotation can help deter diseases. In areas where continuous wheat is grown, cultivation can break down crop residue that harbors certain diseases. Plant disease-free seed. Good weed control from preplant, at planting and throughout the growing season also helps protect against disease and other pests.
Excellent powdery mildew control can be achieved with commercially available fungicides. The decision to use fungicides should be based on scouting for symptoms. It’s important to assess disease severity from the growth stages of tiller elongation through flowering. Experts recommend application timing to keep the upper leaves of the wheat plant disease-free, allowing full potential for grain fill. Other factors affecting fungicide application are infection levels in the field, the susceptibility of the variety and the market price for wheat grain.