By: Faye Bouchard PAg, MSc, Crop Protection Laboratory Manager
Aphanomyces euteiches root rot was suspected in at least one lentil sample so far, based on visual symptoms (caramel coloured roots and presence of oospores in roots). With a good sample (fresh, just starting to show symptoms), these symptoms would present a good indication of Aphanomyces in peas or lentils. However, Pythium also produces oospores in roots, and a PCR test (available from a private lab) would determine more definitively whether this particular pathogen is present in a sample.
Check out these links for more information on root rot or lentil disease.
Wheat Streak Mosaic Virus (WSMV) was detected in a durum sample last week. After observing streaking (yellow and purple, a stress response in durum), stunting, curling leaves, and presence of wheat curl mites, an ELISA test confirmed what was suspected from the symptoms.
According to the North Dakota State University Crop and Pest Report last week, wheat curl mite was also reported in North Dakota recently, with confirmation of WSMV in almost all of the winter wheat samples submitted to their diagnostic lab. Montana is also concerned about the impact of WSMV.
Other causes of yellowing or stress in cereals submitted to the lab so far have included frost damage, stress from warm days and cool nights, and symptoms consistent with florasulam combined with stress.
The lab saw a sample of orange hawkweed (Hieracium aurantiacum L.), which wasn’t thought to be present in Saskatchewan and wasn’t noted in the 2014-15 Saskatchewan Weed Survey. However, it is known in other provinces and is a prohibited noxious weed in Alberta.