Spore trap results confirmed the presence of airborne ascospores in sentinal plots located at COAREC. A large number of spores were captured on the first day of trapping.
The cool, wet weather that is predicted for central Oregon over the next few days will likely be conducive to sclerotia germination and spore release. In general, ascospore production by the pathogen is favored by:
- moderate temperatures (between 50°F and 80°F)
- high soil moisture, rainfall, and/or irrigation.
- conditions that delay or interfere with pollination, such as cool wet weather, can increase the period of susceptibility in grass seed crops.
It is recommended that growers scout fields as grass seed crops approach flowering (anthesis). Protective fungicides should be applied prior to the onset of anthesis to protect unfertilized flowers from infection, and cultivars with prolonged flowering periods may require multiple applications.
Please refer to the PNW Plant Disease Management Handbook for more information (https://pnwhandbooks.org/plantdisease/host-disease/grass-seed-ergot).