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.

According to the model, most ascospores are produced in the Lower Columbia Basin when accumulated degree-days are between 414 and 727. Based on this model, the degree-day threshold was reached on May 19, 2023 in Hermiston, OR (accumulated degree days = 428).

In 2022, the degree-day threshold was met on May 27.