Timely Rain in Most Locales

Rainfall last week and early this week brought precipitation (ranged from 1/2 inch to 4 inches) to much of western Canada. The additional moisture brought a welcome reprieve to parts of northwest and southwest Manitoba, southwest Saskatchewan, central and Peace region of Alberta, and the BC Peace region where drought stress symptoms were appearing. The recent moisture has improved crop conditions (less stress evident and crops covering the ground better) but additional rainfall will be needed again soon to keep pace with crop requirements. Parts of the eastern and interlake regions in Manitoba and northern Peace Region of Alberta are at or above field capacity and any further rainfall will result in additional excess moisture stress.

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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Crop Development Progressing – Staging Remains Variable

Crop growth and development progressed last week especially in areas that were in need of moisture. The canola crop ranges from rosette stage (for the latest fields that were re-seeded due to frost) to early pod on the earliest seeded fields. Generally the crop is bolting to early flower in most regions. Reports of canola germination continue in areas that received their first post-seeding rainfall recently resulting in a ‘second flush’. Most areas continue to report overall crop development as later (about one to two weeks) than normal. Significant heat for growing degree day accumulation and additional rainfall is needed in many areas to bring crop development up to normal.

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 from Saskatchewan Ministry of Agriculture is available at: http://www.agriculture.gov.sk.ca/crprpt090709
The latest crop report from Alberta Agriculture and Rural Development is available at:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/sdd4191#2009
The following maps show growing degree days accumulating across western Canada this growing season: http://www.agr.gc.ca/pfra/drought/prtgdd_e.htm

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Frost in July?

Nights were quite cool last week with minimum temperatures in the neighborhood of 0.6⁰C to 5⁰C across much of western Canada. Pockets of frost Thursday night/Friday morning were reported near Invermay, SK and Two Hills, AB and in the Peace Region in Alberta. Canola fields that are vegetative can recover better after a light frost but maturity may be delayed. Canola plants that are flowering may be damaged by the frost but symptoms may not appear until seed set. Canola flowers that are newly opened (those that are three to four days old) are most sensitive to frost damage. Frost at this very early flowering stage can damage the ovule and cause it to shrivel and not result in seed set. Symptoms of frost damage may appear as missing pods (where complete flower blast occurred) or missing seeds within a pod when ovules were damaged earlier. Canola may be able to respond with additional flower and pod production if weather conditions improve.

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Canola Flowering – Time to Evaluate Sclerotina Risk

With canola beginning to flower, it is time to assess risk for sclerotinia stem rot infection and to determine if a fungicide application will be economical. Remember many factors affect the risk of infection including: heaviness of the crop canopy, amount of moisture received in the two weeks prior to flowering and potential for further rainfall, years since last host crop, disease incidence in the past, and presence of apothecia in neighboring fields. Thin stands which result in a light, open canopy will likely help lower risk in a number of locations this year. However, regular precipitation and high humidity at early flowering can still lead to significant disease development in thin stands especially if plants begin to lodge.

The link https://canola-council.merchantsecure.com/canola_resources/product11.aspx is a "Canola Disease Scouting and Risk Assessment Card" which can help with risk assessment: This card will help determine if fungicide applications are warranted, particularly where yield potential is reduced by late maturity or low plant numbers.

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How to Apply a Fungicide with Variable Stages

This year has certainly been challenging for canola production and, as a result, crop staging is wide ranging in some fields. Should a fungicide be applied now when the oldest plants flower or later with the later-flowering plants? Each field should be assessed individually for risk of infection from sclerotinia stem rot. A few things to keep in mind:

• Thin plant stands are more open and will dry out more readily during the day. Infection risk will be lower unless regular showers or high relative humidity with heavy dews keep the canopy damp.
• Recent rains do not necessarily mean increased risk of infection. Sclerotia require good soil moisture (one to two inches of rain in a one to two week period) to germinate into apothecia and produce spores for infection. Surface soil moisture has certainly been limited recently in many parts of western Manitoba, southwestern Saskatchewan and Alberta. With recent rains it may take about a week for sclerotia to germinate into apothecia and release spores that cause infection. Canola staging may advance enough that this late release of spores is too late to cause significant disease development in earlier maturing fields.
• Scout for apothecia (small golf tee shaped mushrooms that produce the spores) in fields where susceptible crops, such as canola, pulses and sunflowers, were grown last year. The more you find the greater the potential for spore production.
• Generally earliest infections cause the greatest yield loss. If one application is being made, scout fields well to determine when the majority of plants (that are the biggest yield contributors) are at the appropriate stage for fungicide application.
• If the crop staging (and ultimately flowering) is variable, consider a split application. The first application can be made when the first plants reach recommended staging. If necessary, a second application can be made when the remaining plants are ready to be sprayed. Refer to current crop protection guides to determine which products are registered for split application and recommended rates of application: http://www.gov.mb.ca/agriculture/crops/cropproduction/gaa01d01.html
• Consider the lateness of the season and frost-free days remaining. Be realistic with yield goals. If the crop is flowering late, is there enough time to gain a return on the fungicide investment?
• Bayer Weather Command Centre produces a risk map daily for sclerotinia infection based on weather data (temperature and relative humidity) collected from Weatherbug stations located throughout western Canada. If interested in viewing the risk map, visit the following link http://www.bayerweather.ca/ and login into the site with Canola as the ‘username’ and Grower as the ‘password’. Please take note that the login information must be typed with capital and lower case letters exactly as shown. The sclerotinia risk map is located under the risk analysis tab. Access to this site will be for a limited time only and anyone interested in long term access can email askus@bayercropscience.com.

The following link has good photos of a canola field progressing through flowering stages (10% to full bloom): http://www.ag.ndsu.edu/pubs/plantsci/crops/pp1410.pdf

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Insects Found but Not Needing to be Controlled Yet

There were still a couple of reports of cutworms in Saskatchewan this past week but it appears as if larval feeding is winding down as they are beginning to pupate. More information on cutworms is available at: https://canola-council.merchantsecure.com/canola_resources/product22.aspx

The cabbage seedpod weevil threat is also winding down in southern Alberta and southwestern Saskatchewan as many crops are well into or have finished flowering. Only fields that are just coming into flower are still at risk. Reports are that populations were lower than last year and in many fields were below threshold. The economic threshold for the weevil is 20 to 30 weevils in 10 sweeps, depending on crop price. More information is available in the cabbage seedpod weevil section at the following link: http://www.canola-council.org/contents10b.aspx

All across western Canada there were reports of increasing grasshopper populations, but the recent wet conditions seemed to have slowed their attack for the time being. Grasshoppers may become a concern in canola adjacent to fields 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

Insect monitoring traps collected 26 adult diamondback moths near Indian Head, SK recently. However, populations of larvae observed in parts of Saskatchewan are below the economic threshold of 100 to 150 larvae per m2 in immature and flowering fields or 200 to 300 larvae per m2 in flowering and podded fields. Scott Hartley, Saskatchewan Ministry of Agriculture, indicates it is getting too late in the season for multiple generations of this insect to become a threat. More information on diamondback moth is available at the following link: http://www.agriculture.gov.sk.ca/Default.aspx?DN=688b2f99-ad99-423d-900c-c01a1c45d8a1

Cabbage root maggots were reported in Saskatchewan and Alberta. A number of fields in central 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 (as many as 3 maggots per plant root). 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

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Rodents Running Rampant

A number of areas are reporting crop damage due to gopher feeding (as much as a couple of acres surrounding burrows in some fields). The following bulletin from Alberta Agriculture and Rural Development has more information on management and control: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3471

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Suspicious Bud Browning

A number of fields in the Peace region of Alberta (near Rycroft and Spirit River) are exhibiting signs of necrosis (browning and tissue dying) on bud clusters. Symptoms were first noticed on the primary branch. This week reports indicate that some secondary branches are also affected. It is unknown at this time if damage is the result of an environmental stress (e.g. cold temperature) or something else (e.g. herbicide injury). Fields are being scouted thoroughly and information is being gathered to try and determine the cause. If any crop scouts notice similar symptoms in other areas please notify your regional agronomy specialist, as a comparison of conditions and production practices may assist in identifying the problem.

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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, gutzket@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, Saskatchewan Canola Development Commission, 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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