One More Rain Might Do It

Alberta and the BC Peace Region had seasonal daytime temperatures last week which spawned thundershowers in many locations, with rainfall amounts ranging from trace to 2 inches and reports of strong winds and hail. Relatively cool conditions prevailed in the rest of the Prairies with many parts of Saskatchewan and Manitoba receiving rain (trace to 1 1/2 inches). Overall, soil moisture is adequate and warm conditions are needed to advance the crop and hasten maturity. Many areas could use one more general rain before harvest to maximize seed fill. The dry pocket continues in the area near Coronation and Hanna Alberta and there are reports of crops being written off by AFSC (provincial crop insurance).

Maps of current moisture conditions in western Canada from PFRA are available at:
http://www.agr.gc.ca/pfra/drought/prpay09_e.htm
http://www.agr.gc.ca/pfra/drought/prpgs09_e.htm
Additional moisture information for Alberta is available from Alberta Environment at:
http://www.environment.alberta.ca/forecasting/data/precipmaps/weekly.pdf

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Turn up the Heat, Please

Crop development ranges from early bloom (20%) in the late and re-seeded fields to fully podded in the early fields. Some of the very earliest fields in southwestern Manitoba and Saskatchewan are starting to show signs of color change but swathing is still estimated to be about three weeks away. Crop development continues to lag behind the long term average (about one to two weeks behind). Cool conditions persist so far this week and many locations report overnight lows in the single digits (as low as 2 to 3^oC), with Dapp, Alberta reporting a low of 0^oC on Wednesday morning. Across western Canada, significant heat (growing degree days) is needed within the month of August and into early September to have the canola crop mature with good quality at harvest before the first fall frost.

 

The latest crop report from Manitoba Agriculture, Food & Rural Initiatives is available at: http://www.industrymailout.com/Industry/Redirect.aspx?u=101643&q=136876005&lm=19904645&r=157603&qz=d894c75ef34e2808db802fd1a6cb1195
The latest crop report from Saskatchewan Ministry of Agriculture is available at:

http://www.agriculture.gov.sk.ca/crprpt090729

The latest crop report from Alberta Agriculture and Rural Development is available at:
http://www.industrymailout.com/Industry/Redirect.aspx?u=181743&q=136876005&lm=19904645&r=157603&qz=6ad15cbfa8fbdfd5dc53cbb9b9dc4af8
The following maps show growing degree days accumulating across western Canada this growing season: http://www.industrymailout.com/Industry/Redirect.aspx?u=180734&q=136876005&lm=19904645&r=157603&qz=a6c32d13007d2079ecb019feac203a11

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Hail Damage – Getting Too Late to Recover

Thunderstorms last week and over the weekend brought hail to parts of Alberta and central Manitoba. It is likely getting too late in the growing season for canola plants to compensate and recover from severe hail damage. Mid-season hail is also a concern for disease access. The hail wounds on the plant can provide points of entry for disease pathogens such as sclerotinia stem rot, alternaria black spot or blackleg if environmental conditions have been conducive to spore production and disease development. More information about hail damage to canola is available at the following link: http://www.canola-council.org/chapter5.aspx.

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Lygus, Grasshoppers, Aphids, Root Maggots, Bertha and Diamondback Moth

Lygus populations have exceeded economic thresholds in parts of the Peace Region of Alberta and BC and are below threshold and being monitored near Olds and Vermilion, Alberta. When scouting for lygus it is important to note the stage of the crop and insect. Young nymphs will do very little damage compared to later instars and adults. Later maturing fields may still be at significant risk but fields nearing maturity may escape the damage. Fields nearing maturity will be less vulnerable because pod texture becomes rubbery and tougher for lygus bugs to pierce.

Young lygus nymphs are pale green and resemble aphids but have five small black dots and no cornicles. Adult lygus bugs are pale green to reddish brown/black with a “V” mark one third of the way down their backs. Lygus cause damage by feeding on leaves, stems, flowers and pods, resulting in flower blasting and shriveled seeds. There is a range for the economic threshold depending on crop stage and price.  More information is available at the following link: http://www.gov.mb.ca/agriculture/crops/insects/fad12s00.html

Grasshopper feeding on edges of canola fields was reported in the Clyde, Leduc and Barrhead areas and in parts of the Peace Region in Alberta. Grasshoppers may become a concern in canola adjacent to a field cut for hay as the insects migrate to continue feeding. Continue scouting for grasshoppers because if caught early, perimeter spraying may be all that is needed.  A specific economic threshold for grasshoppers in canola has not been established as it is not a preferred host crop, but it is currently considered to be in the range of 7 to 14 per m2, depending on the crop value and cost for control. More information on grasshoppers is available at the following link: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex6463

Aphids have been reported in other crops in southwestern Manitoba and southeastern Saskatchewan. At this time of year, the turnip aphid will cluster on canola stems during flowering and early podding. The economic threshold for aphids in canola is when 10 to 20% of the stems have clusters of aphids. The following link has information on aphid damage, tips for control and economic thresholds in a number of crops, including canola: http://www.agriculture.gov.sk.ca/cpn090804

Bertha armyworm larvae have been observed near Yorkton, SK and in areas of the north Peace Region of Alberta and so far populations appear to be below economic threshold. The economic threshold ranges depending on the cost of control and crop price. The following link provides a chart for the economic threshold range: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm4848

Cabbage root maggots were again reported in Manitoba, Saskatchewan and Alberta.  A number of fields in Alberta had considerable damage. Drier conditions earlier this spring are generally not favorable for root maggots so it is a bit surprising to see significant damage. Unfortunately there are only cultural management tools for this insect pest. More information on cabbage maggot is available at: http://www.gov.mb.ca/agriculture/crops/insects/fad04s00.html. An audio discussion on root maggots and other insect pests with Dr. Lloyd Dosdall, University of Alberta is available at ACPC’s website http://www.canola.ab.ca/.

The Minnesota Canola Council is reporting relatively high trap counts for diamondback moth adults recently. As well, a number of fields are being sprayed for larvae because populations are exceeding economic thresholds. This may result in an increased risk to canola in southern Manitoba along the border, so growers should continue to scout.

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Pay Attention to Pre-Harvest Intervals and Product Registrations

The preharvest interval (PHI) refers to the number of days that the crop should not be harvested after application of a pesticide. Harvest in this context means cutting or swathing. If the crop is harvested before the indicated interval has elapsed, there could be unsafe or unacceptable residues of the pesticide remaining in or on the harvested seeds. Preharvest intervals are listed on the labels of pesticides and under the ‘Restrictions’ section of individual product descriptions in a current provincial Guide to Crop Protection. When pesticide applications are being considered, take note of the required preharvest interval and allow for that time period before harvest. Also, ensure that the product is registered for the intended use and registered to be used on the crop at that stage.

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Affected Patches Appearing – Find out Why

At this time of year (as the canola crop finishes flowering and begins to pod), often stressed or affected patches appear within the field. These patches are often most noticeable because they started flowering at the same time as the rest of the field but are now coming out of flower sooner. If possible, mark these suspicious patches so they can be examined closer to determine what is happening with the canola crop. Are these stressed patches located on knolls (e.g. lacking moisture sooner or could soil fertility be playing a role)? Are root maggots present? Pull plants with roots intact and check for root maggots. Plant disease symptoms can also begin to appear at this time so take a closer look to determine if blackleg or sclerotinia stem rot are present.  Clubroot disease may be another potential explanation. In the first few Canola Watch issues this spring, it was reported that a soil test from west-central Saskatchewan had shown the potential presence of the clubroot pathogen’s DNA. Further testing was being conducted to confirm the results. SaskCanola recently reported that the DNA diagnostic test and a canola plant bioassay confirmed that trace levels of the clubroot pathogen (Plasmodiophora brassicae) were present in that soil sample. More information is found in the press release issued at: http://www.saskcanola.com/news/2009-0721-clubroot.html

While scouting, it is important to follow field entry protocols to maintain proper sanitation and limit the spread of clubroot. More information on sanitation guidelines is available at the following link:  http://www.canolacouncil.org/clubroot/docs/field_entry_1.pdf and more general information on clubroot is available at http://www.clubroot.ca/

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Harvest Approaching – Start Planning Now

If warm, dry conditions prevail, cutting of the earliest canola fields may begin within about three weeks. After flowering (pod filling) is a good time to assess yield potential leading up to harvest. The variable staging this year has not evened out and will require more management at harvest. It may be beneficial to mark or section off fields based on similar staging and yield potential. Know where the greatest yield potential is within the field and plan to focus on protecting it the most. The greatest yield potential includes the plants with most seeds but also earliest maturing to escape a fall frost. Yield potential can be determined by counting the number of pods on a plant and the number of seeds per pod. Pods can be plucked and held up to the light to determine the number of seeds within the pod.  While scouting, think about the approach needed for harvest. Is the staging so variable that a desiccant may be needed to hasten maturity on the latest plants? Would swathing be better than straight cutting or vice versa? Is there a lot of green weed growth that will require a pre-harvest application?

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Keep Malathion OUT of Canola Bins

As bins are prepared for the coming harvest, keep in mind that using malathion on canola seed or in canola storage bins will result in detectable levels of malathion residue because malathion has a strong attraction to the oil in canola seed. Consequently, malathion can move into canola seed from storage bin walls. Detection of malathion residue in canola seed above the allowable limit will result in rejected shipments and increased monitoring.  DO NOT use malathion to treat bins destined to store canola. More information is available at the following link:  http://www.canola-council.org/pesticide_link2.aspx

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Questions & Contacts

Direct questions regarding this report to John Mayko, Senior Agronomy Specialist with the Canola Council of Canada at maykoj@canolacouncil.org, 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, Senior Agronomy Specialist Manitoba, hammondd@canolacouncil.org, 204-729-9011
Anastasia Kubinec, Manitoba Agriculture, Food and Rural Initiatives, anastasia.kubinec@gov.mb.ca, 204-745-5645

Jim Bessel, Senior Agronomy Specialist, Central Saskatchewan, besselj@canolacouncil.org, 306-373-6771

Tiffany Martinka, Agronomy Specialist, Eastern Saskatchewan, martinkat@canolacouncil.org, 306-231-3663
Venkata Vakulabharanam, Saskatchewan Ministry of Agriculture, Venkata.Vakulabharanam@gov.sk.ca, (306)787-4668
Doug Moisey, Senior Agronomy Specialist, East Central Alberta and Northwestern Saskatchewan, moiseyd@canolacouncil.org, 780-645-9205
Erin Brock, Agronomy Specialist, Peace Region, brocke@canolacouncil.org,
780-568-3326
Murray Hartman, Alberta Agriculture and Rural Development, murray.hartman@gov.ab.ca, 403-782-8024
Kerry Clark, BC Ministry of Agriculture and Lands, Kerry.Clark@gov.bc.ca, 250-784-2559

The Canola Watch Report provides just-in-time information on canola production to growers and industry. Contributors to the Canola Agronomy Network are:

Alberta Canola Producers Commission; Alberta Agriculture and Rural Development, SaskCanola, Saskatchewan Canola Growers Association, Saskatchewan Ministry of Agriculture, Manitoba Canola Growers Association, Manitoba Agriculture, Food and Rural Initiatives, Peace River Agriculture Development Fund, B.C. Ministry of Agriculture & Lands, Agriculture and Agri-Food Canada, and the Canola Council of Canada.

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