I have run across a few wheat fields in Burlington County today with heavy infestations of Powdery Mildew. Mild temperatures, high relative humidity and dense stands favor the development of powdery mildew. The disease can result in reduced kernel size and test weight and ultimately lower yields. Greatest yield losses occur when the flag leaf becomes severely diseased by heading. It is important to protect the flag leaf and leaf below from disease for maximum yield. The Penn State Agronomy Guide has further information on managing diseases in small grains. Fungicides are available for controlling powdery mildew. Fungicides can be applied based on the level of disease in the field, the known susceptibility of the variety, and the selling price of the grain.