A number of reports of bacterial blight in oats around agricultural Manitoba were featured in the provincial ag department’s latest insect and disease report.
Symptoms include light green to water-soaked spots or stripes on the leaves; a photo can be seen in the full report.
Entomologist John Gavloski of Manitoba Agriculture, Food and Rural Initiatives at Carman says bacterial blight favours humid, wet weather and recent warm, dry weather should halt further development.
"It is important to note that this disease is caused by a bacterium, not a fungus, and therefore fungicide applications will not provide any control. Warm, dry weather will allow crops to grow through these symptoms and it is unlikely to cause measurable yield losses."
High populations of aster leafhoppers continue to be found in some cereal fields in Manitoba. While leafhoppers can be present in large numbers in field crops, and can potentially vector aster yellows to these crops, they can be most damaging in horticultural crops. The MAFRI report has a review of studies on aster leafhoppers and whether they are an economic threat to Prairie crops.
Some high cutworm populations were reported form fields near Dauphin, Binscarth, Hamiota, Strathclair, Rivers, Cypress River, and Glenlea. Gavloski asks that producers and agronomists contact him if they see high populations of cutworms. Someone will come to the field to collect cutworms for a research project on parasitoids of cutworms.
Diamondback moth traps around Beausejour and Morris continue to have the highest counts, and all the higher counts continue to be in the eastern part of Manitoba. West of Carman the counts have all been low. Traps near Beausejour and Stead has fairly high counts (114 and 80 respectively) over the past week.
So far MAFRI has not had any reports of high levels of larvae of diamondback moth. A table of the highest cumulative trap counts for diamondback moth in Manitoba, as of June 7, is available in the report. MAFRI’s full data set for adult counts of diamondback moth can also be seen online.