Spores were detected on all days during the first week of June, albeit at lower numbers than observed during the latter half of May:

Both honeydew and sclerotia have been observed on Kentucky bluegrass and perennial ryegrass plots located at the Hermiston Agricultural Research and Extension Center:

Protective fungicides should be applied at the onset of anthesis to protect unfertilized flowers from infection, and 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 using the “Leave a reply” link above.

Spore production was steady during the final week of May, with over twice as many spores captured (1,503 spores/week) compared to the previous four weeks (641 spores total):

Honeydew and sclerotia have been observed in research plots located at the Hermiston Agricultural Research and Extension Center.

Many Kentucky bluegrass seed fields in the area are mature or nearing maturity. Field scouting for honeydew at this time can help identify infected fields which may present difficulties during swathing, harvesting, and seed cleaning operations.

Updated spore counts are available for the Lower Columbia Basin of Oregon:

The final week of May began with extremely large spore counts (>40,000 spores/day), but spore production tapered off as the month wound down. However, the number of spores captured per day was still relatively high (>600 spores/day) compared to other locations.

Protective fungicides should be applied at the onset of anthesis to protect unfertilized flowers from infection, and 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 using the “Leave a reply” link above.

Updated spore counts are available for the Lower Columbia Basin of Washington:

Ascospores were detected on three out of seven days.

Based on field observations, many cultivars of Kentucky bluegrass and perennial ryegrass are flowering in the Lower Columbia Basin.

Protective fungicides should be applied at the onset of anthesis to protect unfertilized flowers from infection, and 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 using the “Leave a reply” link above.

Updated spore counts are available for central Oregon, the Lower Columbia Basin, and the Grande Ronde Valley of Oregon:

After a brief lull, increased spore counts were observed between May 21 and May 26 at COAREC in Madras, OR
Spore counts remain relatively high at our perennial ryegrass research site near Hermiston, OR, with nearly 80,000 spores being detected on a single day (May 24).
Sporadic, but significant, spore numbers were observed in the La Grande area between May 15 and May 21.

Honeydew has been observed in non-treated, artificially-infested plots at the Hermiston Agricultural Research and Extension Center.

In contrast to airborne ascospores, honeydew is contact-, splash- or insect-dispersed.

The presence of honeydew at harvest can make swathing and combining more difficult. Late season scouting and field monitoring will help to develop harvesting/seed cleaning schedules and identify potential problem fields or areas that will need increased monitoring in the 2021 season.

The easiest way to scout for honeydew is to gently brush the flowers and developing seeds with your hand as you walk the field – if you feel a sticky substance, it may be honeydew from ergot. Aphids, if present, can also produce a sticky substance called honeydew, so, be careful not to confuse ergot honeydew with honeydew secreted by these insect pests.

Upon closer examination, ergot honeydew can often be seen being exuded directly from infected florets (red arrows).