Fusarium Head Blight: Practice prevention, there is no cure.

Spring and summer of 2019 won’t soon be forgotten. Abundant rainfall fueled by humid conditions made planting a difficult time. As the season progressed moisture led to fungal disease and in eastern Kansas, Fusarium head blight reared its ugly head.The causal agent of Fusarium head blight, or FHB, is a fungus that lives in residue left by grass crops like wheat, corn, and oats as well as non-cultivated grass species. During wet conditions, the fungus grows and produces spores. These spores may be spread by wind or rain. Problems arise when ideal conditions for fungal growth and spread occur at or around wheat flowering. Rainfall and humidity combined with 65 to 80ºF temperatures at flowering increase the risk of FHB infection. Though infection occurs at flowering, symptoms of FHB aren’t realized until later in grain fill. During late-milk and early-dough, the tan infected spikelets are easily spotted against the green unaffected portion of the heads (as seen in Figure 1 above). As the heads mature, the contrast disappears; however, infected kernels are readily visible at harvest in the grain. Fusarium affected kernels are shriveled and chalky white or pink in appearance. DON, a type of mycotoxin, is associated with FHB infection. As the name implies, mycotoxins can be toxic to humans and animals. The only effective treatment timing for FHB is at flowering, when infection occurs. After flowering, there is no treatment, there is no cure, there is only waiting to see what damage has been done. Caramba Fungicide applied at 13.5 fl oz per acre at flowering (Feekes 10.5.1) can suppress FHB, protecting the wheat head when it is most vulnerable. In 2019, FHB took many wheat fields by surprise. Practice prevention in 2020, treat your wheat at flowering with 13.5 fl oz of Caramba and protect your wheat from FHB.