Dr. Robyn Roberts
Field Crops Pathologist and CSU Assistant Professor Robyn.Roberts@colostate.edu*
970-491-8239; @RobynRobertsPhD (Twitter)
*Email is the best way to reach me
DISEASE OBSERVATIONS
Mosaic virus symptom reports are on the rise. Importantly, viruses typically exist in a complex in Colorado, including Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and High Plains Wheat Mosaic Virus (HPWMoV). At the Wheat Field Days, I found virus symptoms at three of the four sites I visited. All of the samples we have tested so far this year have been positive for both TriMV and WSMV. In WSMV-resistant varieties, WSMV levels have been low, so the symptoms observed in these varieties are very likely caused primarily by TriMV. The drought has contributed to the severe virus disease symptoms this year, since the mites go to plants during times of drought to find water.