South Missouri wheat fields should be scouted now to determine if a fungicide should be applied to the foliage. Most wheat growing in south Missouri will be at the split-boot stage of growth the week before or after Easter, and that is the stage of growth fungicides should be applied if needed. A fungicide applied at the split-boot stage of grow will help protect wheat leaves and heads from most late season yield-robbing wheat diseases such as leaf and stem rust, leaf and glume blotch, powdery mildew, and tan spot. These diseases will not develop in all wheat fields so each field must be scouted separately to determine if a fungicide is needed. Dr. Laura Sweets published an excellent review of information about wheat diseases and the fungicides for protecting wheat against these diseases in this newsletter last week. Her review included a comparison of how well the labeled fungicides protect wheat against each disease.
Some of the fungicides labeled for application to wheat up to the time wheat begins to bloom include Headline (BASF), Twinline (BASF), Quadris (Syngenta), Quilt (Syngenta), and Stratego (Bayer). A complete list of fungicides labeled for foliar application to wheat is shown on pages 163 to 172 in the online University of Missouri Extension publication M171 titled, "2011 Missouri Pest Management Guide: Corn, Cotton, Grain Sorghum, Rice, Soybean, and Winter Wheat." One application of one of these fungicides at the split-boot stage of wheat growth will help protect the wheat from most yield-robbing diseases this spring.
More information about wheat disease management in Missouri is available at your county MU Extension office and is posted at http://extension.missouri.edu/explorepdf/agguides/pests/ipm1022_Pp17-26.pdf. Following these suggested procedures will give farmers a better chance of producing high wheat yields and profits in 2011.
REVISED: September 30, 2013