Spore traps have detected the presence of airborne ergot ascospores around Kentucky bluegrass production areas in the Grande Ronde Valley.
Spore counts are relatively low and sporadic compared to other sites. However, a relatively few number of ascospores can begin an infection, and the honeydew (secondary) stage of the disease can amplify the disease in a field before harvest. Our research has shown that, at least in some cases, up to 30% of infections can be caused by honeydew.
It is also important to note that the spore traps currently being used at all sites sample a relatively small volume of air (about 3,800 gallons of air/day). Consequently, the ascospores that are detected and reported likely represent a small proportion of the total number in the area.