June 18, 2014 – Issue 11

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  • Four the week

    Some canola fields face intense competition from grassy weeds this year.

    Two-hit wonder. Does your canola really need a second in-crop herbicide application? Only certain circumstances — like the one photographed above — make it worthwhile.

    Summer heat A new PAMI project will look into summer effects on stored canola, and help set best practices to prevent heating: Aerate to warm it, turn it to warm it, or just leave it cold? Have you checked stored canola lately?

    Clubroot conundrum. No current commercial clubroot-resistant canola hybrids have resistance to the different strain found in Alberta. Equipment sanitation and long rotations will be required to prevent the pathogen’s buildup and spread.

    Insect Aside. Are striped flea beetles taking over? Maybe, but that shouldn’t change the steps in making the decision to apply an in-crop insecticide.


  • Map of the week

    AAFC map_GDD base 0 April 1-June 16 2014
    AAFC map_GDD base 0 April 1-June 16 2014 legend

    Click “read more” to compare this map with growing degree days (GDDs) for 2013 at this time, and see why this information is important for canola agronomy.


  • June 18 Quiz

    Stinkweed top

    In this week’s quiz, we ask you to identify five weeds — including the one above. With the answers, we also provide useful agronomy information for each weed.


  • Second pass of herbicide: When does it make sense?

    Some canola fields face intense competition from grassy weeds this year.

    Growers who usually spray twice may not need that second pass this year if the canopy has closed, weeds are behind the crop, and the recommended application window is past. The crop should outcompete the weeds all on its own, and the economic benefit of the second herbicide application just won’t be there. But if the crop looks like the photo above, a second spray will likely pay.


  • Weather delays and the risk from idle sprayers

    The longer a herbicide sits in a sprayer, the greater the risk that it is going to hang up in the tank. Sprayers should be cleaned at the end of every work day regardless if the same product or tank mix is being sprayed the following day.


  • Spraying tip: How to ID an inversion

    The cloud behind the sprayer is a sign of inversion, and higher drift risk. Source: Tom Wolf

    Early mornings and evenings when conditions can be the best for spraying can also be the worst because of possible air temperature inversions. Air temperature inversions — when air temperatures actually increase as you get higher above the ground — create ideal conditions for tiny spray droplets to become suspended in the air and drift considerable distance from their target. This cool air mass hovering near the ground can flow like water to valleys and lower areas.


  • Different clubroot pathotype confirmed

    Canola with small developing clubroot galls. Source: Stephen Strelkov

    Research has confirmed the presence of a different clubroot pathotype in the Edmonton region and none of the commercially available clubroot resistant varieties in Western Canada are effective at managing it.

    Stephen Strelkov, the University of Alberta researcher leading this project, has identified other resistance genes that could work, but they are not currently in commercial hybrids.


  • Flea beetles: More striped

    Striped flea beetles.

    Striped flea beetles, shown above, seem to have become the dominant species in many regions, with crucifer species harder to find. This has been observed in fields in central Alberta, in particular. Research shows that striped flea beetles emerge earlier than crucifer flea beetles, so one thought is that the crucifers have not emerged, yet. However entomologists expect that most, if not all, of the flea beetles from both species should have emerged.


  • Cutworms: How to scout


    Cutworm scouting begins with a walk through the field looking for bare patches, chewing damage in foliage, or clipped plants.

    If you find patches of missing or damaged plants, dig around healthy plants next to the missing of damaged plants. Cutworms have likely moved on to these nearby healthy plants. Many cutworms are underground during the day or feed only at the soil surface, so day-time scouting requires digging. In moist soils, cutworms will stay close to the surface. In dry soils, they may go down 8-10 cm (up to 4”).


  • Canola storage research: Summer tips

    Feeding sensor wires through probes.

    PAMI, with funding from the provincial canola growers organizations, is running a storage project this summer to test the best management practice for canola bins as they move from winter to spring to summer. Should they be turned to warm them up? Aerated to warm them up? Or left alone so they stay cold for as long as possible?


  • Keep It Clean: Keep treated seed out of hauled grain

    As growers transition from seeding back to grain hauling to get bins cleaned out and ready for harvest, there are two timely “Keep It Clean” messages to keep in mind:

    1. Carefully clean all treated seed and seed treatment dust out of the trucks and augers. Elevators are watching for this, and may reject loads where treatment is detected. This also presents a potential trade risk for any canola customers who may find seed treatment traces in a shipment.

    2. Do not use malathion on bins planned for canola. Malathion is used to control grain storage insects in bins, but malathion can be absorbed by canola seed stored in those bins. Therefore, malathion cannot be sprayed in canola bins any time within six months of canola going into those bins.


  • Top 10 things to watch for this week

    If you see bare patches, start diagnosing.

    While scouting this week, look out for missing plants, odd patterns, plant damage and anything else out of the ordinary. Here is our top 10 list of things to look for — but others could be at play.


  • Hail damage: Economic loss depends on crop stage

    The later that hail occurs, the more likely for yield loss, given that plants simply have less time to recover. Plants at the 6-leaf stage, for example, that lose most of the leaf area on the main stem can still live, but these leaves will not regrow. The plant will be delayed, and more of the yield potential — which will be lower than before the hail — will come from side branches.


  • How to help water-stressed canola

    This canola spent a few days under water.

    Wet soils cause an oxygen deficiency, which reduces root respiration and growth. Root failure reduces nutrient uptake, and plants will eventually die unless drowned areas dry out quickly.


  • Top dressing a weak crop


    Excess moisture can reduce soil nitrogen levels through leaching and denitrification. A top dress could address this. But excess moisture and other weather factors that set back the crop may also reduce overall yield potential, which means the crop may not take up as much nutrient anyway.


Canola Watch