June 20, 2012 – Issue 17

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  • Issues of the week

    Cutworms continue feeding, flea beetles may still be a threat for late-seeded canola, and cabbage seedpod weevils (shown above) have arrived on early-seeded canola in the southwestern Prairies.

    Earliest crops are starting to flower, which means sclerotinia prediction time. Wet weather and a dense canopy at flowering should encourage higher rates of sclerotinia stem rot infection in regions where the disease has been present in the past.


  • Photo quiz of the week

    What’s going on the leaf on the right?


  • Aerial options for weed control

    If weeds and crop are advancing toward the end of the application window and the ground is too soft and wet to support a sprayer, then aerial spraying may be the best economic response. Roundup WeatherMax is the only glyphosate registered for aerial application at this crop stage. Liberty (glufosinate) is registered for aerial application at this stage, as is Centurion. None of the Clearfield herbicide system products is registered for aerial application on Clearfield canola. Poast and Assure II have aerial labels.


  • Canola can recover from hail up to 20% flower

    Hail that hits canola before flowering or at early flowering may have a minimal effect on yield. Plants will flower longer and compensate.


  • Look for signs of sulphur deficiency

    An in crop application of sulphur can make financial sense for canola if: Growers could not put the desired rate on at seeding. Yield potential improved and growers want to add sulphur to their nitrogen top up. If field conditions have been excessively moist, sulphur may have moved lower in the soil profile. Canola shows signs of sulphur deficiency.


  • Insect update: Cabbage seedpod weevil

    Begin sweep netting for cabbage seedpod weevil when canola enters the flowering period. Select 10 locations within each field and at each location, count the number of weevils from ten 180° sweeps. At current prices, the threshold will be around 20-30 per 10 sweeps (2-3 per sweep). Anything below that and the canola plant will generally compensate for seedpod weevil damage to the buds and flowers.


  • Insect update: leaf rollers, wireworms, bertha, flea beetles

    Leaf rollers probably aren’t worth controlling. Wireworms will live up to 4 years as a larvae and will feed on canola. Bertha monitoring begins. Flea beetles numbers are falling for the season.


  • Sclerotinia control: Early canola starting to flower

    Earliest canola is starting to flower this week, which means the sclerotinia spray decision looms. Spray timing, if a grower decides to go for it, should be within the window from 20% to 50% bloom. Canola can reach 20% flower in 4-5 days after first flower. The article also includes information on adding boron to a fungicide tank mix.


  • Coming events

    Alberta: June 21: Farming Smarter crop walk, Lethbridge June 21: Growing with Canola crop walk, St. Paul Saskatchewan: July 11-24: Public Crop Research Field Days Manitoba: July 11: Canola Day at Crop Diagnostic School in Carman, Man.  Click here to register.


Canola Watch