In this issue:
(click the bookmarked links below to move to specific sections of this report)
Soil moisture conditions vary widely
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
Soil moisture conditions across western Canada continue to range from fair to excess. Most areas have adequate to excess moisture. Many areas received more precipitation over the past week, with heavy rains in most regions in Manitoba which exacerbated the already wet conditions. Conditions in much of eastern Manitoba continue to worsen due to extensive flooding damage, and symptoms from excess moisture in other regions are becoming more pronounced with the recent heat. Much of Saskatchewan received warmer and drier weather with only scattered showers, reducing the pockets of surplus moisture to mainly the southeast region. The soil moisture in Alberta is generally good, with some pockets of excess in the southwest and some depletion of soil moisture in areas of central Alberta and the northern Peace.
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/crprpt050703.pdf
Additional moisture information for Alberta is available from Alberta Environment at:
http://www3.gov.ab.ca/env/water/ws/data/precipmaps/precipmaps.html
Canola crop development has accelerated with the warmer weather over the past week, and is now near normal. Growth generally ranges from bolting for late seeded canola fields to late bloom and early podding for early seeded fields, with most fields well into flowering. Overall, established canola crops throughout western Canada appear to be in good condition, except for areas that have suffered flooding damage for an extended period of time. These conditions are now most prevalent throughout much of Manitoba, southeastern Saskatchewan and southwestern Alberta. Patchy stands due to poor emergence on rain packed, clay knolls are also reported in various areas throughout Saskatchewan.
There are reports of blossom blasting (significant pod abortion) in some fields, particularly in the eastern and northwest parts of Manitoba and the northwest and northeast regions of Saskatchewan. There are many questions about the cause of these symptoms. The two most likely causes of reduced pod formation are environmental stress or previous insect feeding damage to the buds. While blossom blasting is normally associated with hot and dry weather, any stress on the plant can contribute to an increase in the number of aborted pods. For example, in soils at or near saturation the warmer weather over the past week will have increased the plants’ requirement for oxygen, causing increased stress and more pronounced symptoms. Other contributing factors could include heavy rain, hail or wind storms which cause flowers to drop prematurely. For more information about the effects of waterlogging and hail on canola check the following links:
http://www.canola-council.org/stress_moisture.aspx
http://www.canola-council.org/stress_hail.aspx.
Insect feeding on buds, flowers and young pods can also cause blasting (buds turn white and fail to develop), flowers to fall without forming pods, or pods to drop without maturing. Diamondback larvae were the most likely culprit this year, as they were present in many areas at the critical budding and bolting stage. It is important to note that canola does have the potential to compensate right up to the end of flowering by increasing the number of branches, flowers and pods produced, provided conditions allow it to. For a detailed discussion of how canola flowers, and its ability to compensate following a period of stress, check the following link:
http://www.canola-council.org/gs_stage6.aspx.
Diamondback moth larval activity was generally slow over the past week, although some feeding damage was noted in northwest Saskatchewan and northwest of Edmonton in the areas around Westlock and Barrhead, and in some areas of the Peace. Growers should be scouting for emergence of the next generation from the middle to end of flowering through early seed set. Also, it is important to note that sweep nets are not appropriate for determining if the economic thresholds of either diamondback moth or bertha armyworm larvae have been breached. For more information on late season scouting techniques refer to the following press release: http://www.canola-council.org/about-us/media-news/media-releases/media-jun2005.shtml
If there are about 100 to 150 larvae per square metre feeding on buds, an insecticide application may be needed to minimize yield loss. That threshold rises to between 200 and 300 per square metre at late flowering through early podding. Click on the following link for an insect image library which includes an example of bud damage from diamondback larval feeding:
http://www.canola-council.org/images_insects.html
For current diamondback moth survey updates, refer to the following links:
http://ncrxeis4.agr.gc.ca/ppmnMaps/
For more information on diamondback moth, refer to the following SAFRR link:
http://www.agr.gov.sk.ca/DOCS/crops/integrated_pest_management/insects/Diamond.asp?firstPick=
Crops&secondpick=Integrated%20Pest%20Management&thirdpick=Insects
For a picture of a parasitoid wasp of diamondbacks, refer to the following link: http://www.canola-council.org/parasiticwaspsid.aspx
Cabbage seedpod weevil spraying is nearing completion in southern Alberta as the majority of the crop has progressed beyond the appropriate bloom stage for application. For late fields that are not yet beyond 20% bloom, scout with a sweep net to ensure that numbers are not above the threshold of three to four per sweep at early flowering. For more information on cabbage seedpod weevils, refer to the following link:
http://www.agr.gov.sk.ca/docs/crops/integrated_pest_management/insects/cabbageweevil.asp?firstPick=
Crops&secondpick=Integrated%20Pest%20Management&thirdpick=Insects
Bertha armyworm moth traps are monitoring adult moth activity throughout western Canada. Moth numbers have been low for most areas. However, trap numbers in the Wanham, Eaglesham and Fahler areas of the Peace region continue to escalate. Spikes in moth numbers and emergence of some bertha armyworm larvae were also noted in areas of southwestern Manitoba and northeastern Saskatchewan. Growers should be aware of the increasing numbers and be starting to scout for the larvae.
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/$department/deptdocs.nsf/all/prm2521
For interpreting bertha armyworm trap numbers, refer to the following link:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2526?opendocument
For current bertha armyworm survey updates, refer to the following link:
http://ncrxeis4.agr.gc.ca/ppmnMaps/20050704_bertha_armyworm_pr.pdf
There have also been some reports of the painted lady (or thistle) butterfly larvae being mistaken for bertha armyworm. Painted lady larvae are similar in size, but dark purple to black in colour with long spines on each segment of the abdomen. They prefer Canada thistle, but will feed on canola foliage. However, they usually occur in small patches and insecticide control is rarely justified. For more information check the following link: http://www.canola-council.org/paintedlady.aspx.
Alfalfa loopers continue to be reported in parts the Peace and central Alberta. Damage involves snipping off buds and flowers during the bolting and bloom stages, and affected areas have been patchy within fields. However, some diseased larvae are now being found clinging to plants, indicating they have been parasitized by a virus. Initially the parasitized larvae will resemble a fluid filled sack, and then dry out leaving a dried carcass. Scout for these diseased larvae, because high levels of parasitism will reduce the need for spraying. For more information on alfalfa looper, refer to the following link: http://www.canola-council.org/alfalfalooper.aspx. Clover cutworms were also reported in areas of the Peace, so check this link for more information: http://www.canola-council.org/clovercutworm.aspx. Finally, high levels of thrips have been reported in northwest regions of both Saskatchewan and Manitoba. They are an opportunistic pest that mostly feed on pollen and are rarely an economic pest. However, they do cause curling or twisting of pods that is quite noticeable. For pictures all of these insects as well as thrips damage, check the image library at: http://www.canola-council.org/images_insects.shtml.
The fungicide applications for sclerotinia are winding down in many areas, due to a combination of advanced crop stage and reduced risk as a result of warmer and drier weather in much of Saskatchewan and Alberta. However, for later maturing crops with full canopy closure it is important to remember that high soil moisture levels combined with warm temperatures create prime conditions for the disease. In particular, the crop stage and abundant apothecia indicate that northern parts of central Alberta may still be at risk. Scout for the presence of apothecia in canola fields and in neighboring fields, as part of sclerotinia stem rot checklist evaluation. There have been many questions regarding how to identify apothecia and on their development. Refer to the following link for a summary on apothecia developed by Penny Pearse of SAFRR from a paper published by McLaren, et al in the Canadian Journal of Plant Pathology:
http://www.canola-council.org/PDF/summaryofapotheciaresearchpaper.doc
Refer to the sclerotinia stem rot checklist to help assess risk in later maturing fields and determine whether or not to spray a fungicide. Scouting for apothecia will be part of that evaluation, and accurate identification is important. For pictures of apothecia and other common mushrooms in crops (courtesy of Kelly Turkington, AAFC), as well as photos regarding apothecia and initial sclerotinia development on leaves (courtesy of Penny Pearse, SAFRR) refer to the following link:
http://www.canola-council.org/PDF/Sclerotiniainfo.pdf#zoom=100
http://www.canola-council.org/sclerotiniaforecast_test.aspx
For, more information on the life cycle of sclerotinia, refer to the following link:
http://www.canola-council.org/sclerotiniacycle.aspx
For the current list of recommended fungicides for sclerotinia control, refer to Manitoba’s 2005 Crop Protection Guide: http://www.gov.mb.ca/agriculture/crops/cropproduction/gaa01d01.html
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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