Updated spore detection results from the Ergot Alert spore trap network are below. Spores were detected in Central Oregon (COAREC) and the Lower Columbia Basin of Washington State (Pasco North and Eltopia East).

This season we have 17 spore traps deployed in grass seed fields, including 6 in central Oregon, 3 in the Grande Ronde Valley, and 8 in the lower Columbia Basin of Washington State.

So far, spores have been detected in central Oregon (Madras area) and the lower Columbia Basin of Washington State (near Pasco).

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.

Updated spore counts are available for Central Oregon and the Grande Ronde Valley:

Spore production continues in Central Oregon (top) and the Lower Columbia Basin (bottom):

A very low level of spores were detected at the Baker County site in samples collected between June 16 and June 22.

Spores were not detected at the Union County site during the same period.

Updated spore counts for Central Oregon are shown below:

Stripe rust has also been observed in experimental plots at COAREC, so scouting for this disease is recommended. There are many fungicide options available for stripe rust control – for more information please refer to the Pacific Northwest Plant Disease Management Handbook: https://pnwhandbooks.org/plantdisease/host-disease/grass-seed-stripe-rust

Updated spore counts for the Hermiston area are shown below:

Spores have been detected at the Union County spore trapping site. Spores have not yet been detected at the Baker County site.

As of June 13, no spores have been detected at either the Baker or Union County spore trap sites.