Nathan Kleczewski, Extension Specialist – Plant Pathology; nkleczew@udel.edu
I have made reference to a larger window for FHB application, specifically a 5/6-day post Feekes 10.5.1 window.The data from that collaborative project conducted across 7 field sites have now been published in Plant Disease in an article entitled, “Efficacy of Fungicide Applications during and after Anthesis against Fusarium Head Blight and Deoxynivalenol in Soft Red Winter Wheat.”The study, conducted by colleagues at The Ohio State University and the University of Illinois, examined the use of Prosaro®, applied at Feekes 10.5.1, and either 2, 4, 5, or 6 days after Feekes 10.5.1.Ratings of FHB and DON in the post-anthesis applications were generally not significantly different from those for the anthesis applications. Relative to the check, Feekes 10.5.1 +2 resulted in the highest percent control for both IND and DON, 69 and 54%, respectively, followed by Feekes 10.5.1+4 (62 and 52%), Feekes 10.5.1+6 (62 and 48%) and Feekes 10.5.1 (56 and 50%). Feekes 10.5.1+2 and +6 significantly reduced IND by 30% and 14%, respectively, relative to the anthesis application. Post-anthesis applications did not, however, reduce DON relative to the anthesis application. These results suggest that applications made up to 6 days following anthesis may be just as effective as, and sometimes more effective than, anthesis applications at reducing FHB and DON.