Issues of the week

July 18, 2012 - Issue 21

Sclerotinia stem rot risk is still high in most regions. Fungicide labels allow for spray up to 50% flower. Spraying this late may work well if the crop seems to be flowering for a long time or the crop is at various stages — two scenarios that can extend the time at 50% flower, and also increase the disease risk.

Take a look for root maggot, especially for canola seeded into canola stubble. Root maggot feeding has been high this year, especially in the Peace Region, and the best management option is to take the field out of canola for at least one year. Increasing the seeding rate may also help if rotation is out of the question.

While pulling plants to look for root maggot, scout for bertha armyworm, lygus and whatever other insects may be feeding. Bertha numbers could be high this year, given that cumulative counts in some traps are already well into the high risk category. High counts in a region means a high probability at least some fields will exceed thresholds, but even if trap counts are low in your area, scout anyway.

Note the pre-harvest interval for insecticides and fungicides. Some crops have advanced past the PHI for some products.

Canola Watch