Updated spore counts for Central Oregon are shown below:

Honeydew has been reported in Central Oregon.

Weather conditions in Central Oregon are expected to be favorable for spore production over the next week, and some Kentucky bluegrass cultivars are flowering in the area. Protective fungicides should be applied prior to onset of flowering and throughout anthesis to protect unfertilized ovaries from infection. Cultivars with prolonged flowering periods may require more than one application.

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 27, 2022 in Hermiston, OR (accumulated degree days = 422).

At this time in 2021, accumulated degree-days were 646.

Updated spore counts for Central Oregon are shown below:

Weather conditions in Central Oregon are expected to be favorable for spore production over the next week, and some earlier flowering Kentucky bluegrass cultivars are nearing anthesis in the area. Protective fungicides should be applied prior to onset of flowering and throughout anthesis to protect unfertilized ovaries from infection. Cultivars with prolonged flowering periods may require more than one application.

Spore trapping for the 2022 Ergot Alert Network was started May 5-6. We currently have rotating arm samplers located at the following spore monitoring locations:

  • Lower Columbia Basin: Two rotating arm samplers placed in a commercial perennial ryegrass seed field near Hermiston. Spores have been detected at this location.

  • Central Oregon: Two rotating arm samplers in artificially-infested Kentucky bluegrass plots at the Central Oregon Agricultural Research and Extension Center. Spores have been detected at this location.

Depending on your region, some Kentucky bluegrass and perennial ryegrass cultivars may be nearing anthesis. Protective fungicides should be applied immediately prior to onset of anthesis and throughout the flowering period to protect unfertilized ovaries from infection. Cultivars with prolonged flowering periods may require more than one application.

The PNW Plant Disease Management Handbook is a great resource for more information on fungicide options for ergot (https://pnwhandbooks.org/plantdisease/host-disease/grass-seed-ergot) and other diseases of grass grown for seed.

For more information, please contact Jeremiah Dung.

This work is funded by the Eastern Oregon Kentucky Bluegrass Working Group and the Oregon Seed Council.

Lower Columbia Basin: Burkard spore trap in artificially-infested perennial ryegrass fungicide test plots at the Hermiston Agricultural Research and Extension Center. Spore production is continuing at this site. On May 26, over 27,000 spores were detected:

Upper Columbia Basin: Burkard spore trap and rotating arm sampler in a Kentucky bluegrass seed field near Paterson, WA (naturally occurring inoculum). Spore production is continuing at this site:

Central Oregon: Burkard spore trap in Kentucky bluegrass plant growth regulator test plots at the Central Oregon Agricultural Research and Extension Center (naturally occurring inoculum). Spore production is continuing at this site:

Union County: Rotating arm samplers placed in two Kentucky bluegrass seed fields with moderate and high histories of ergot (naturally occurring inoculum). Over 2,700 spores were detected during the week of May 19-May 26 at Field #1. Spores have not been detected at Field #2.

Many fields are in full flower (anthesis). Protective fungicides should be applied immediately prior to onset of anthesis and throughout the flowering period to protect unfertilized ovaries from infection. Cultivars with prolonged flowering periods may require more than one application.

Please refer to the PNW Plant Disease Management Handbook for more information on fungicide options for ergot (https://pnwhandbooks.org/plantdisease/host-disease/grass-seed-ergot), or contact Jeremiah Dung if you have any questions.

This work is funded by the Eastern Oregon Kentucky Bluegrass Working Group, the Washington Turfgrass Seed Commission, the Oregon Seed Council, and the Agricultural Research Foundation.

Lower Columbia Basin: Burkard spore trap in artificially-infested perennial ryegrass fungicide test plots at the Hermiston Agricultural Research and Extension Center. Spore production continues to increase at this site:

Central Oregon: Burkard spore trap in Kentucky bluegrass plant growth regulator test plots at the Central Oregon Agricultural Research and Extension Center (naturally occurring inoculum). Spores are still being detected this site:

Many fields are in full flower (anthesis). Protective fungicides should be applied immediately prior to onset of anthesis and throughout the flowering period to protect unfertilized ovaries from infection. Cultivars with prolonged flowering periods may require more than one application.

Please refer to the PNW Plant Disease Management Handbook for more information on fungicide options for ergot (https://pnwhandbooks.org/plantdisease/host-disease/grass-seed-ergot), or contact Jeremiah Dung if you have any questions.

This work is funded by the Eastern Oregon Kentucky Bluegrass Working Group, the Washington Turfgrass Seed Commission, the Oregon Seed Council, and the Agricultural Research Foundation.