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Issues Archive
Use the expandable navigational menu on the left hand column to find a specific issue of Canola Watch by year, month and date.
May 31, 2012
Weather and herbicide performance
Herbicide performance is on a sliding scale depending on the weather. Cloudy days with highs of 10 C after a night near 0 C will tend to result in herbicide performance at the low end. Sunny days with highs of 15 C after a night of 3 C will provide improved control. Sunny days with highs of 20 to 25 C after a night of 10 C will provide optimum control.
Issues of the week
Weed control remains top of mind. Without good weed control, all other inputs — including fertilizer and top quality hybrids — cannot achieve the return on investment expected of them. We have tips this week on weed control in cool conditions. Continue to check for flea beetles. Crucifer populations are starting to peak — they […]
Photo quiz of the week
Spraying in cool temperatures
Cool cloudy days after cool nights will result in lower herbicide efficacy than applications made in warm sunny days. Cloudy days don’t provide the photosynthetic activity required for many herbicides, including Group 10 glufosinate. And nights near freezing followed by days with highs that barely reach 10 C will not provide high metabolic activity required for best results from Group 9 glyphosate.
Good time for top dressing
If good moisture has increased yield outlooks and nitrogen may not be sufficient, top dress applications should occur before the 5-leaf stage of the crop.
Are you sure it was flea beetles?
You maybe went to a field to scout for flea beetles, but take time to look around. Consider all possible causes when you notice uneven emergence, patchy growth and unthrifty plants. Get a second opinion when necessary. You need to know what caused a problem before you can take effective corrective action.
How to do a plant count
When scouting, take time to check the plant stand. Look for blank areas and also look for thin areas. The plant
Gopher management
Gophers can eat up large areas within a canola field. Strychnine baits and, in some jurisdictions, mix-it-yourself strychnine liquid is available for gopher control. Phostoxin is also registered for gopher control, but this is a restricted use product that requires a special permit for purchase and application.
Canola in excess water. Will it survive?
Canola is quite susceptible to water logging and shows a yield reduction after only three days with wet feet. If only a small percentage of the field is lost, reseeding may not pay off — especially if that small percentage includes a bunch of pot holes all across the field. And wait to see how the crop recovers from saturated soils before investing any more in fertilizer.
May 24, 2012
Issues of the week
Early season scouting is the theme of the week. Most canola crops are seeded and many have emerged. Canola plants face various threats in these first few weeks, including weed competition, flea beetles, cutworms and frost. Weed control will be a top priority, especially for fields that didn’t get a pre-seed burnoff. Walk the fields […]
Photo quiz of the week
Spray weeds early in crop
In-crop weed control should occur as early as possible since canola is much more vulnerable to weed competition prior to reaching complete ground cover. Past research has demonstrated an advantage of 3 bu./ac. for controlling weeds at the 1-2 leaf stage of canola versus 3-4 leaf, and a 7 bu./ac. advantage versus 6-7 leaf. At $12 per bushel, that’s $36 to $84 per acre more profit with no added cost.
Blackleg symptoms found on two-leaf canola
Blackleg lesions are already showing up on some canola fields. In high risk fields, consider fungicide as an additional tool to limit infection and yield loss. Headline, Propiconazole (Bumper, Pivot, Propel, Tilt) and Quadris are registered for blackleg management in canola.
Insect update: Cutworms active
Some cutworm species are already quite active — dingy, for example — and can consume canola plants before they even emerge or shortly thereafter. Dingy cutworms will also eat wheat, barley and peas, so scout all crops. Scout bare or clipped patches, digging around in the border areas between missing plants and healthy plants. That’s where the cutworms will be feeding.
Insect update: Early diamondback feeding
Early diamondback moth (DBM) eggs are hatching, and some young canola plants could begin showing “window paning” of the leaves. Spraying for DBM at this stage is rarely needed but it has happened. Consider a spray if between 25% and 33% of the plant material is eaten or damaged, and larvae are still present on the plant.
