Soil Moisture – Extremely Dry to Excess

Several storms brought much needed rain to parts of southwest, central and northwest regions of Manitoba. Soil moisture is adequate in most of these regions but additional rainfall will be needed again soon to support the rapid crop growth and development. Parts of the eastern and Interlake regions of Manitoba are still wet from the large rainfall event 10 days ago and signs of excess moisture stress are beginning to appear (crop yellowing and drowning out in low lying areas). Much of Saskatchewan received rain in the last week but only enough to support the crop for a limited time. A significant general rain is needed shortly to continue advancing the canola crop. Parts of southern Alberta also received rain (minimal shower to two inches) which is providing temporary relief from the poor soil moisture conditions. However, many areas are surviving from shower to shower and are in need of a significant general rain or continued regular showers. The extremely dry conditions continue in the area north of Medicine Hat along the Saskatchewan/Alberta border (Hanna and Oyen areas) since no rainfall was received. Other parts of central Alberta received scattered thundershowers in the past week, but rainfall amounts were highly variable. The southern Peace region of Alberta did receive much needed rainfall (one inch) and the BC Peace region received about two inches. The western areas of the northern Peace region received rain but not eastern areas where conditions are dry.

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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Variable Crop Staging

Canola staging continues to be quite variable within an area and within a single field in some areas. Re-seeded and late seeded fields range from 4- leaf to rosette stage. Rainfall in areas that were extremely dry is resulting in a ‘second flush’ of germinating canola, resulting in staging from cotyledon to bolting in the same field. Where canola is stressed (e.g. excess moisture in Manitoba or extremely dry in Alberta), pre-mature bud formation and bolting is occurring from small, unthrifty plants. Where soil moisture is adequate, good growing conditions over the past week have helped advance canola development. Earliest seeded fields are at the bolting stage to early flowering stage with the very earliest seeded fields in full flower. Most areas continue to report overall crop development as later (about two weeks) than normal. Continued warm weather and a return to more average moisture are certainly needed 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/crprpt090702
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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Lots of Hail

With the rainfall last week, came hail to a number of areas (Dauphin, Treherne and Notre Dame, MB; Duck Lake, Frontier, SK; Claresholm, Spirit River, AB). Hail stones were large in some areas (golf ball size at Frontier, SK) and fell for a significant period of time (hail fell at supper time at Claresholm, AB and hail stones were still present on the ground at noon the next day). Obviously hail damage in these situations is expected to be significant. In other areas, smaller hail stones for a brief period of time will result in much less crop damage. A well established root system and the ability to develop secondary flower clusters will help the plants recover. At the rosette stage, yield loss will be mainly related to lost leaf area. A general rule of thumb is that lost yield will equal about a quarter of the percentage of leaf area lost. When buds and flowers are lost due to injury, the plant recovers rapidly by the development of flowers that normally would have been aborted. The plant also develops flowering branches from growth buds lower down on the plant, replacing to a degree, the lost buds, flowers and pods. However, one concern this year will be the additional delay in maturity until plants recover. There are reports that some crops received 100% damage. If crops have been totally destroyed, there may still be time to seed green feed and qualify for crop insurance. Consult your local insurance agency for more information.

The following link has good information on assessing hail damage on canola: http://www.canolacouncil.org/contents5.aspx

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Sclerotinia – Assessing the Risk

Canola is beginning to flower in many areas and now is the time to begin assessing risk for sclerotinia stem rot infection 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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Sclerotinia – To Spray or Not to Spray with Variable Staging

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.
• Many areas have experienced dry conditions lately. Sclerotia require good soil moisture (one to two inches of rain in 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. 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.
• 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?

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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Number of Insect Pests Found

There were a couple of reports of cutworms in Saskatchewan 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

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 three provinces report increasing grasshopper populations although it appears as if few, if any, canola fields have been sprayed to date. 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

Few diamondback moth adults have been caught in monitoring traps throughout western Canada this year. 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. 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

Red turnip beetle was sprayed on a limited number of acres via perimeter spraying in the Peace region of Alberta. This insect moves into a field by migrating from a neighboring field that was in canola last year. As a result, control can usually be achieved with spraying field edges. More information on this insect is available at:
http://www.agriculture.gov.sk.ca/Default.aspx?DN=4cc8d2a0-9fb3-4459-8e63-e306abfb9530

Lygus bugs were reported near Raymore, SK, Morinville, Grimshaw, and La Crete, AB. The population at La Crete was sprayed. Other populations are below threshold and being monitored. The economic threshold of lygus bug in canola ranges depending on crop price and cost of control. Fields should be monitored during flowering but there is no scientific evidence that yield loss occurs at this stage. Control is economical when the crop is podded and populations exceed the economic threshold. There may be an opportunity for some migration of lygus bugs into canola from alfalfa crops now being cut for hay. More information on lygus bugs is available at the following link: http://www.gov.mb.ca/agriculture/crops/insects/fad12s00.html

Cabbage root maggots were reported in Saskatchewan and Alberta. A couple of fields in central Alberta had considerable 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

Bertha armyworm adult moths have been caught in traps across western Canada recently. Moth numbers at all locations are low resulting in a low risk assessment at this time. Trap results will continue to be reported in Watch in the coming weeks. More information on bertha armyworm is available at: http://www.agriculture.gov.sk.ca/Default.aspx?DN=defc273b-db17-48fd-a341-32a7c541fbe0

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Aster Yellows To Appear Later?

Leaf hoppers in relatively high populations have been found south of Red Deer, AB. This insect is not of economic importance in canola but rather may be an indicator that Aster yellows may be prevalent later in the season. Aster yellows is caused by a phytoplasma, a plant pathogenic micro-organism. The phytoplasma is carried from plant to plant by sap-sucking leafhoppers. Infected plants are easily seen because they tend to stand taller, are discoloured and have squashed, bladder pods present. Although highly visible, aster yellows is not usually present on a large enough percentage of plants to cause economic losses. This is partly because even when leafhopper numbers are high the proportion of the leafhopper population carrying the phytoplasma is typically very low. More information on aster yellows is available at the following link: http://www.agriculture.gov.sk.ca/Default.aspx?DN=8ae6ce2b-1684-48b5-a307-20ba8ee5c485

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Crop School Season is Here

Up for a great learning experience? There are a number of crop training events organized across western Canada to challenge even the most seasoned agronomist. For more information or to register refer to the list at the following link: http://www.industrymailout.com/Industry/Redirect.aspx?u=114562&q=136265941&lm=19904645&r=156796&qz=0c48f657fb9d7b0440d6714ddff2becf

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Recruiting Disease Survey Participants

Faye Dokken, Provincial Specialist – Plant Diseases with Saskatchewan Ministry of Agriculture is looking for cooperators to participate in a canola disease survey this summer. Representatives from the Ministry would like permission to enter canola fields and collect a soil sample (for clubroot screening). While at the field, representatives will also take note of other canola diseases that may be present. Interested producers can contact Faye at (306) 787-4671 or Faye.Dokken@gov.sk.ca.

In Manitoba a similar disease survey is also planned, so interested co-operators in that province can contact Anastasia Kubinec (Oilseed Business Development Specialist, MAFRI) at 204-745-5645 or Anastasia.Kubinec@gov.mb.ca or Dr. Debra McLaren (Scientist, Crop Production Pathology, AAFC) at 204-578-3561 or dmclaren@agr.gc.ca.

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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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