A predictive model for ergot ascospores was developed for the Lower Columbia Basin of Oregon that uses accumulated degree-days (beginning January 1, with a base temperature of 50°F and upper threshold temperature of 77°F) to forecast when ascospores are likely to be present.

Accumulated degree-days as of May 10 were 435 in Hermiston, OR (orange line). According to the model, most ascospores are produced in the Lower Columbia Basin when accumulated degree-days are between 414 and 727.

At this time in 2019, accumulated degree-days were 365 (dotted line).