Foliar Fungicides ForWheat Disease Control

JACKSON, TENN.
    Stage of Growth to Apply Wheat Foliar Fungicides: Close attention must be paid to the stage of growth to obtain maximum benefit from foliar fungicides. If the application is made too late, then infection could have already occurred. If application is made too early, the flag leaf and head will not be protected. If powdery mildew or rust diseases are threatening the flag leaf, the best time to apply a foliar fungicide is a Feeke’s scale 10.3 (when ½ of the head has emerged). Prosaro and Carmaba fungicides are labeled for head blight suppression (Scab) and should be sprayed at F 10.5.1 (beginning of flowering) especially when continuous wet weather occurs during flowering. Research for the last two years indicates that spraying a Strobilurin type fungicide may increase the level of deoxynivalenol (DON) levels (sometimes called Vomitoxin). Spraying a Triazole type fungicide such as Prosaro or Carmaba at the blooming stage reduces the chance of high levels of DON. Wheat with high levels of DON may not be saleable.
   Each application must be made in at least 5 gallons of water per acre by airplane or at least 20 gallons of water per acre with ground rigs. Always use a spreader-binder that is labeled for fungicides with either application method. Remember: Users are required to read and follow all label instruction for any of these fungicides.Δ
DR. MELVIN NEWMAN: Extension Plant Pathologist, University of Tennessee