A predictive model for ergot ascospores was recently developed for the Lower Columbia Basin of Oregon.

The model 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.

Accumulated degree-days as of April 30 were 259 in Hermiston, OR (black solid line).

At this time in 2017, accumulated degree-days were 200 (orange dotted line).

For more details on the model and how it was developed, please see our recent publication in the journal Plant Disease (https://doi.org/10.1094/PDIS-05-16-0609-RE).

The HAREC ergot spore trap site was set up in one of our perennial ryegrass research plots on April 23rd.

Each spore trap site consists of a Burkard 7-day volumetric air sampler and a WatchDog data logger that measures air and soil temperatures, relative humidity, and soil moisture.

The samples are collected from the air sampler weekly and returned to the lab for analysis.