Below is a summary from the Manitoba Insect & Disease Update dated August 8, 2018
Symptoms of clubroot in canola have been confirmed in a number of additional fields, bringing the total number of new fields in 2018 to eight.
Six of these fields are in the RM of Pembina, one in the RM of Lorne, and one in RM of Dufferin.
Many of these new reports are due to the increasing awareness of the disease by growers in areas where it has been previously reported.
It's recommended that growers investigate any patches where canola is underperforming, especially areas that may typically do poorer like field entrances and low-lying areas of the field.
Soybean aphids have been reported for the first time this year.
However, given their very late arrival, low levels, and the advancement of the soybean crop, the risk of them being at economical levels in fields in Manitoba this year is very low.
Bertha armyworm continues to be found in canola fields in western Manitoba, but there have only been a few fields where it was reported at economic levels.