In this issue:
(click the bookmarked links below to move to specific sections of this report)
The Alberta Canola Producers Commission (ACPC) has developed an Alberta focused version of this report. Visit the ACPC website at: http://www.canola.ab.ca
Canola crop development in most areas continues to be delayed by the cool weather and precipitation received this past week. Many areas (except for the BC Peace region) received from 6 to 75 mm of rain this past week. Swathing of early seeded canola continues slowly in most areas. It ranges from up to 70% complete in parts of southern Manitoba, Saskatchewan and southern areas of Alberta to just getting underway in parts of northwestern Manitoba, central Alberta and the Peace region. There are also some late seeded fields that are still at the end of flowering. Overall, established canola crops throughout western Canada appear to be in good to excellent condition, except for the areas that experienced extended flooding this past spring. Additional reports of pod abortion and shallow pod depth caused by high temperatures and lack of rainfall in July and early August will likely reduce yields compared to the amount of biomass produced. Normally, these lower levels of soil moisture are not a problem, but the generally shallow root systems of many of this year’s canola crops have predisposed the canola to moisture stress.
For current maps of moisture conditions from PFRA for western Canada, check the following link: http://www.agr.gc.ca/pfra/drought/prpay05_e.htm
The latest crop report from Manitoba Agriculture, Food & Rural Initiatives is available at: http://web2.gov.mb.ca/agriculture/mwcr/index.php
The latest crop report and soil moisture map from Saskatchewan Agriculture, Food & Rural Revitalization is available at: http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt050821.pdf
Additional moisture information for Alberta is available from Alberta Environment at: http://www3.gov.ab.ca/env/water/ws/data/precipmaps/precipmaps.html
Frost was reported this past week in parts of northern Saskatchewan, central Alberta (Didsbury, Three Hills, Irma, Mayerthorpe) and much of the Peace region. Although the frost damage was light in many of these areas, there were reports of temperatures as low as -3 to -7 degrees C in low lying areas. Growers need to be patient to accurately determine the level of damage after a frost. To determine when to swath after a frost, check the extent of damage 2-3 days after the frost.
The condition of the frost affected areas will likely fall into one of three main categories, with appropriate swathing strategies for each category. Carefully assess each field and note which scenario the majority of the plants fall into.
Scenario 1: when there is little evidence of frost damage. The pods remain mostly green or tan-green, with few, if any, white spots on the outside of the pods. The seeds inside are mostly intact. Check the colour of the inside of the seeds as well. If the outside of the seeds are starting to turn, the insides should be yellow or a light lime-green. If seeds are still green on the outside and the inside of the seeds are still watery, the outside seed coats should remain intact and turgid. In these cases, leave the crop to continue to mature until further seed and/or pod colour change occurs.
Scenario 2: when there are only white specks on the outside of the pods, or only a few seeds in immature pods that are not intact, or only a few seeds in the upper plant parts are prematurely browning. Premature browning occurs when the outside of the seed has been damaged by the frost and the inside of the seed remains dark green. Check the following link for a photo of moderate crop damage, including premature browning of seed vs. normal seed: http://www.canola-council.org/production/Frost/frost.html
In these cases, the fields should be left and monitored on a daily basis to evaluate further crop changes. If no further damage is evident, the remaining crop may continue to fill and mature. If the seeds continue to deteriorate and/or pod integrity declines, begin swathing to conserve seed volume.
Scenario 3: when there is considerable whitening of the outside of the pods for a majority of the plants. Check the previous link for a photo of severe crop damage. In this case, the pods will begin to shrink and desiccate rapidly, and swathing should begin immediately using the dew to reduce pod shelling and pod drop to conserve any seeds in those pods. In all cases, monitoring should be done daily or every other day to evaluate further crop development and conditions, especially if warmer temperatures and sunshine return. For a more detailed discussion on the effects of frost on various crops, refer to the following SAFRR link: http://www.agr.gov.sk.ca/docs/crops/frostdamage.pdf
Bertha armyworm activity continues to require spraying in the previously reported areas of the central Peace near Eaglesham and Wanham, AB with further movement south towards Woking, east-central Alberta near Vermilion, Lloydminster and Wainwright, northwestern Saskatchewan between Lloydminster and Neilburg, and Laird, and northwest Manitoba in the Swan River Valley and areas around Roblin. Other areas with continuing bertha armyworm activity include Southey and Raymore, SK. Some fields in the central Peace and northwestern Manitoba have been resprayed due to a combination of factors including high populations, cooler temperatures, poor spray penetration into the crop canopy and less susceptible insects at the moulting stage.
If numbers are exceeding threshold levels and an insecticide treatment is needed, be sure to choose a registered insecticide with an appropriate pre-harvest interval. This is especially true for canola that needs more than one insecticide application and/or is close to reaching maturity. As crops reach maturity, the pods become drier and tougher and less appetizing to insects. Crops that are swathed will dry down further, thereby making them even less appealing for insect feeding.
Remember that for determining appropriate preharvest intervals, harvest is defined as the point at which the plant is cut, which means swathing or straight cutting. Preharvest intervals for various insecticides range from 7 days for products such as Decis and Matador to 21 days for products such as Lorsban. Ensure that proper preharvest intervals are followed to eliminate problems with subsequent residues that can impact marketing the crop. Remember that grain companies and crushers keep samples of all deliveries and can trace problems back to the source. Do not jeopardize your farm’s revenue and Canada’s reputation by taking short cuts!
For current diamondback moth and bertha armyworm survey updates, refer to the following link: http://ncrxeis4.agr.gc.ca/ppmnMaps/
For more information on the bertha armyworm, including accurate identification and thresholds for insecticide control, refer to the following links:
http://www.canola-council.org/bertha.aspx
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2521
As the canola crop reaches maturity, swathing time is another great opportunity for field scouting. Flea beetle populations have shown up in some areas, and their presence at swathing can be a good gauge of possible infestations next spring. Also, watch for abnormal areas that have wilted, or for prematurely ripening plants within canola stands that are otherwise healthy. The cut stubble allows for an accurate assessment of diseases such as fusarium wilt, sclerotinia, blackleg and clubroot that restrict water and nutrient uptake by plants.
Alternaria black spot continues to be found in canola crops across the prairies and is at higher levels in western regions of Manitoba. Crops with black spot lesions covering a large proportion of pod surfaces are at increased risk for shattering and are poor candidates for delayed swathing or straight combining. For more information on Alternaria black spot refer to the following link:
http://www.canola-council.org/alternariasymptoms.aspx
New strains of blackleg have been found in Manitoba and eastern Saskatchewan in recent years. Efforts are being made to determine the occurrence and prevalence of these new strains. Growers who notice elevated blackleg levels in MR and R rated varieties and who would like to participate in a scientific survey should collect samples and have them tested to determine what strain is present. Interested growers should e-mail Dr. Dilantha Fernando at d_fernando@umanitoba.ca for sampling and shipping instructions.
The hot and dry weather earlier this summer has caused purpling and premature plant colour change in many canola fields. This is a relatively normal response to stress and growers need to ensure that seed colour change is occurring when they assess the proper time to swath. The colour of mature plants and pods will vary among varieties. Some will appear ripe on the outside before the seeds are mature, so avoid using plant colour as a gauge to proper timing. Open up pods on the main stem and look at the colour of the seeds to accurately assess swathing timing.
Last year, time of swathing recommendations were changed to reflect research results obtained after several years of Canola Council Canola Production Centre trials. Recent research indicates that the optimum stage to swath for both yield and quality is up to 60% seed colour change. This enables many growers to start swathing at 30% to 40% seed colour change without sacrificing significant yield or quality. It widens the "swathing days" window for all growers, including those with large canola acreages. When conditions are hot and dry, avoid swathing. Swath during cool evening hours, at night or early in the morning to allow plants to dry down at a slower rate. This reduces the chance of green seed.
When assessing seed colour, also check seed firmness. Under cool conditions, seeds near the top of the plant may continue to fill and become firm before the lower seeds begin to turn colour. Also, be conscious of disease-infected or hail-damaged fields and do not let the premature ripening of the diseased or damaged plants influence the time of swathing. Realize that the bulk of the yield is likely still coming from the healthy plants. A better strategy than swathing early to capture more yield is to swath during dew periods to prevent shattering of the damaged plants. To learn more about proper field assessment, refer to the revised Canola Council publication "Canola Time of Swathing Guide" or visit the Canola Council website:
http://www.canola-council.org/pub_swathing.shtml
There continue to be many questions regarding swathing timing for canola fields with variable growth caused by uneven emergence or stress from early season flooding. Growers should assess where the majority of their yield will come from and manage accordingly. If the majority of the field is still green, swathing should start when adequate seed colour change occurs in these areas. In fields where green and mature areas are more equal in size, be sure that seeds in the green areas are firm and no longer translucent. Swathing should be delayed as long as possible to allow for seed colour change to start in the green areas. To minimize losses in the ripe areas, growers should consider swathing in the evening or early morning.
Growers considering early swathing to avoid or reduce green seed levels from frost need to remember that swathing prior to 15-20% seed colour change will likely lose some yield potential. Also, the canola has to dry down sufficiently to reduce freezing damage and the canola may need to be swathed for several days before this stage is reached, especially if conditions are cool and damp.
There are a number of growers considering straight cutting their canola this year. To be successful, consider the following factors:
Crop Canopy – the crop should be well knitted and slightly lodged to reduce the chance of pod shelling and pod drop. Remember that pod integrity (including petiole strength which influences pod drop) can be affected by frost.
Disease – the crop should be relatively free from diseases including blackleg, fusarium wilt, sclerotinia and alternaria. These diseases can cause premature ripening, which can in turn cause pod shattering.
Hail - Crops affected by hail are poor candidates for straight cutting due to the probability of greater disease infection through damaged tissue and reduced pod integrity from physical damage. Also, any late season hail often causes greater levels of damage to standing crops than swathed crops.
Send questions regarding this report to John Mayko, Agronomic Research & Extension Manager with the Canola Council of Canada at maykoj@canola-council.org ph/fax: 780-764-2593.
Direct specific questions regarding regional issues to one of the following Canola Council of Canada regional agronomists or provincial oilseed specialists:
Derwyn Hammond, Agronomist, Manitoba,
hammondd@canola-council.org, 204-729-9011
Rob Park, Manitoba Agriculture, Food & Rural Initiatives,
rpark@gov.mb.ca, 204-745-5665
David Vanthuyne, Agronomist, Eastern Saskatchewan,
vanthuyd@canola-council.org, 306-782-7799
David Blais, Agronomist, Western Saskatchewan,
blaisd@canola-council.org, 306-895-2122
Jim Bessel, Senior Agronomist, Northeastern Saskatchewan,
besselj@canola-council.org, 306-373-6771
Bill Greuel, Saskatchewan Agriculture, Food & Rural Revitalization, wgreuel@agr.gov.sk.ca, 306-787-2756
Doug Moisey, Agronomist, Central Alberta,
moiseyd@canola-council.org, 780-645-3624
Christine Mardell, Agronomist, Peace River Region,
mardellc@canola-council.org, 780-518-1513
Matthew Stanford, Agronomist, Southern Alberta,
stanfordm@canola-council.org, 403-758-6660
Murray Hartman, Alberta Agriculture, Food & Rural Development,
murray.hartman@gov.ab.ca, 403-782-8024
Kerry Clark, BC Ministry of Agriculture, Food & Fisheries,
Kerry.Clark@gems9.gov.bc.ca, 250-787-3213
The Canola Watch Report provides just-in-time information on canola production to growers and industry. Contributors to the Canola Agronomy Network are:
Manitoba Agriculture & Food; Manitoba Canola Growers Association; Agricore United; Cargill; Saskatchewan Wheat Pool; United Farmers of Alberta; Saskatchewan Agriculture, Food & Rural Revitalization; Saskatchewan Canola Growers Association; Saskatchewan Canola Development Commission; Alberta Agriculture, Food & Rural Development; Alberta Canola Producers Commission; BC Ministry of Agriculture; Food & Fisheries; and the Canola Council of Canada.
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