There has been the usual increase in samples submitted to the Crop Protection Lab in July. Submissions have increased for this time of year compared to last year with the majority in May and early June being environmentally related. The dry spring with fluctuating temperatures from over 30 degrees C and frost during this period accounted for many of the sample diagnoses, including both field crops and shelterbelts. Later in June and in July more of the samples submitted were related to herbicide injury in various other crops. Even with the dry conditions, root rot in cereals, pea and lentil have been on the increase. Typically, the symptoms associated with Fusarium root rot – caramel-coloured or dark brown roots – have been observed. However, in the case of pulse crops oospores, indicative of Aphanomyces sp. or Pythium sp.) were observed after plating. Rhizoctonia has also been identified. The lab is currently testing for suspected wheat streak mosaic virus in a few cereal samples.
The largest increase in lab submissions has been for Dutch elm disease, a greater than 40 per cent increase in submissions compared to this time of year in 2020. The Crop Protection Lab offers Dutch elm disease testing free for Saskatchewan residents in a joint effort with the Ministry of Environment to help prevent the spread of the disease. The samples are from trees from various urban areas as well as private Saskatchewan residents. For information on how to submit samples refer to the fact sheet on the ministry website.