F. graminearum also grows in soybean and wheat stubble, so this adds to the overall high levels of F. graminearum inoculum we have in Kentucky. If the weather is not favorable for infection during this period, it makes no difference how many spores blow onto the wheat head. The take home message is that FHB is not highly impacted by previous crop or tillage level in Kentucky. When weather is favorable for FHB, and crops are in susceptible stages, an abundance of spores of F. graminearum assures a high levels of FHB, regardless of previous crop or tillage. When weather is unfavorable for FHB during susceptible stages, the crop escapes infection.
Weather is the decisive factor.
Escape of FHB is also common because of the relatively short period of susceptibility for wheat. Farmers should not use fear of FHB as a reason for not giving no-till wheat a try. This non-link between tillage and FHB may not be the same everywhere. Specifically, any factor or situation that would reduce the widespread occurrence of wind-blown spores of F. graminearum in an area, such as might occur where fewer, larger fields are the norm, might make the tillage of residue, especially corn residue, more important in the overall FHB picture. By John Hartman Yellows is again appearing as a disease of ash trees in Kentucky landscapes.