It is important to consider the risk for Fusarium head blight (FHB), or scab, development as wheat approaches flowering. The fungus that causes FHB, Fusarium graminearum, infects wheat during flowering, beginning at FGS 10.5.1. Symptoms appear later in the season and include bleached spikelets on the head, and small or shriveled grain kernels, commonly called “tombstones”. The fungus also produces mycotoxins, such as deoxynivalenol, or DON, which can accumulate in the infected grain. Rainy, warm, and humid weather conditions favor disease development. If varieties susceptible to FHB have been planted, or farmers are worried about the risk of FHB development, they may want to consider a fungicide application at early flowering for suppression of FHB. To accurately growth stage wheat and determine when wheat is beginning to flower, please see Purdue Extension publication ID-422 “Managing Wheat by Growth Stage”.
For more information about Fusarium head blight and fungicide timing for FHB, please see Purdue Extension publications BP-33 Diseases of Wheat: Fusarium Head Blight (Head Scab), and BP-145: Diseases of Wheat: Revised Fungicide Spray Recommendations for Fusarium Head Blight
