Canola Watch Reports

2007 Canola Watch Reports

#10 Western Canada – July 5, 2007

In this issue:
(click the bookmark 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

Crop development continues to vary widely. Earlier seeded crops in Manitoba, Saskatchewan and southern Alberta are into full bloom and early podding, whereas crops in other areas seeded in early-mid June are at the seedling stage. Seasonal temperatures have advanced the crop in most areas, but parts of central and northern Saskatchewan and Alberta are 1-2 weeks behind last year in terms of average crop stage.

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 Agriculture, Food & Rural Revitalization is available at:
http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt070702.asp

The latest crop report from Alberta Agriculture & Food is available at: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/sdd11486.

Variable precipitation from trace amounts to over 125 mm was received across many parts of the west. Many areas continue to suffer from excess moisture, but other areas such as southern Alberta and the Peace near Lacrete and Beaverlodge are getting quite dry and would welcome some rainfall soon. For current maps of moisture conditions from PFRA for western Canada, check the following links for precipitation since September 1 and April 1 respectively:
http://www.agr.gc.ca/pfra/drought/prpay07_e.htm
http://www.agr.gc.ca/pfra/drought/prpgs07_e.htm

Additional moisture information for Alberta is available from Alberta Environment at: http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf

Excess moisture continues to be the most common crop development issue across western Canada. Most of Manitoba, southeastern, north-central and northeastern Saskatchewan, central Alberta between Didsbury and Ponoka and the central Peace near St. Isadore, Rycroft, Eaglesham and Fairview continue to suffer crop damage from wet conditions. The wet conditions continue to delay weed and disease spraying operations. For more information on the effects of excess moisture, refer to the June 20 report at: http://www.canola-council.org/canola_watch_report_2007_08.html

In some later seeded crops in Alberta and Saskatchewan, growers are considering their second application of either glyphosate or Liberty. Prior to automatically applying the second herbicide pass, first consider whether or not the second pass is warranted given the remaining weed pressure. Also, if the canola canopy is starting to reach complete ground cover, the herbicide may not reach targeted weeds. Growers are cautioned when applying late first applications or the second applications of herbicides when the crop is at or past the bud stage, as late spraying could potentially lead to crop stress and blanks on the main stem. Refer to the following Canol@Fact (http://www.canola-council.org/PDF/Jun13_Canola_Fact_Sheet.pdf )for more information on weed control timing including second applications and to the following Canol@Fact at http://www.canola-council.org/PDF/May24_How_Many_Weeds.pdf for more information regarding weed populations and economic thresholds.

Remember to keep scouting fields on a regular basis to detect crop development problems early. Consider establishing a scouting tramline by driving an ATV in an ‘X’ or ‘W’ pattern in the field to establish pathways for crop scouting. This will allow for easier scouting with minimal trampling at later crop stages, especially once the crop is blooming.

The hot weather forecast for many areas this week may identify plants within a field that are wilting prematurely. These prematurely wilted plats should be dug up to determine the cause of the wilting, which could be caused by clubroot, as well as other factors such as sclerotinia and root maggots. For more information on identifying clubroot, refer to the following link: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex8593

Extensive spraying for cabbage seedpod weevils continues in southwestern Saskatchewan and throughout southern Alberta south of Hwy. 1. Sweep counts in many fields report up to 15-20 weevils per sweep. For more tips on scouting and controlling cabbage seedpod weevil, refer to the following links: http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/agdex2538
http://www.directfocus.com/canolamanual/chapter10b.html#ch10b_sec7

Diamondback moth larvae continue to be found in fields across central Manitoba, southern and eastern Saskatchewan, and southeastern Alberta. Numbers of up to 6 larvae per plant have been noted in Saskatchewan and insecticide spraying has occurred. However, larvae in Manitoba were noted to be entering the pupal stage, so growers in all areas should be withholding spraying when the larvae begin pupating. The pupal stage lasts from five to 15 days depending on environmental conditions, then adult moths of the next generation emerge, begin laying eggs and the cycle repeats, with the eggs hatching in about five or six days. Growers should then be on the alert for damage from this next generation.

Growers should use caution before spraying for diamondbacks at this early stage because spraying is likely to destroy beneficial parasitoids, which help in reducing damage from subsequent generations. For a picture of a parasitic wasp of diamondback, refer to the following link: http://www.canola-council.org/parasiticwaspsid.aspx

For more information on diamondback moth, refer to the following SAFRR link:
http://www.agr.gov.sk.ca/docs/production/Diamond.asp

Grasshoppers continue to be reported in many parts of the Peace region. Although most damage from grasshoppers usually occurs on cereals and forage grasses, damage to canola can occur if other food sources are not present. Scout carefully to determine whether the species noted are actually pest species and whether damage is occurring to canola. For more information regarding identification of grasshoppers, refer to the following web link from Dr. Dan Johnson at the University of Lethbridge: http://people.uleth.ca/~dan.johnson/htm/dj_gh_guide.htm

Monitoring of bertha armyworm moths is taking place across the prairies, with increasing moth numbers reported in some areas. Once the bertha armyworm moth maps are developed, their web links will be reported in future Canola Watch reports.

Heavy root maggot populations are being reported in some fields near Vermilion, AB. Although there are no effective methods of in-crop control, there are some agronomic practices that can be used to try to reduce damage in future years. For further information on root maggots, refer to the root maggot section in the following link: http://www.directfocus.com/canolamanual/chapter10b.html#ch10b_sec16

Slugs have been reported in north-central Alberta near Barrhead, Neerlandia and Westlock. Damage from slugs has been noted occurring as either complete plant disappearance or feeding of leaf tissue. Slugs are not normally a problem in canola crops in western Canada and the reasons for this local outbreak are currently under investigation. There are no registered insecticides for slug control in western Canada, so growers should not be spraying insecticides for this purpose.

The high levels of soil moisture in many areas combined with warm temperatures and crops at full ground cover, creates conditions that are conducive to sclerotinia development. However, with warmer and drier weather in the forecast for many areas, risk levels may change, so producers should carefully consider all of the factors highlighted in the sclerotinia stem rot checklist before making this decision. These factors include how heavy their crop canopy currently is, the amount of moisture received in the two weeks prior to flowering and potential for future rainfall, years since last host crop, disease incidence in the past, and the presence of apothecia in neighboring fields where host crops were grown previously. Target yield, fertility program and expected value of the canola crop are also points to consider.

A publication called the Canola Disease Identification and Sclerotinia Risk Assessment Card is available to assist growers and crop scouts with this decision. It includes the stem rot checklist and pictures to aid in accurately identifying the apothecia of the sclerotinia fungus. A PDF version can be found at http://www.canola-council.org/PDF/canola_plant_disease_risk.pdf#page=1 or contact your local Canola Council Agronomy Specialist.

If a producer’s risk assessment based on checklist results and/or petal testing suggests that spraying may be warranted, splitting fungicide applications may be an option. An initial reduced fungicide application at 20 to 30% bloom will help control early onset of the disease. If conditions become drier, a second application may not be needed. However, if this approach is taken and conditions remain wet and humid, a second application will be needed to maximize the benefits of spraying the fungicide. Producers should assess these factors and consult their local agronomist or chemical representative to determine if a single or a split fungicide application is best for their particular situation.

For growers who have decided to apply a fungicide to control sclerotinia, determining the bloom stage of the crop is important. The optimum stage for a single fungicide application is when the maximum number of flowers is open but little if any petal drop has taken place, usually at or slightly above 30% bloom. Typically at this stage in B. napus canola there is an average of about 20 flowers open on the main stem, with some flowers open on secondary branches but little or no pod formation. Some early seeded fields are past the 50% bloom stage and into pod formation, and are now too advanced for effective fungicide application. For more information on bloom stage identification check the following link: http://www.canola-council.org/sclerotiniachemical.aspx.

Direct questions regarding this report to John Mayko, Senior Agronomy Specialist, Parkland West (West Central AB), 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 agronomists or provincial oilseed specialists:

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; 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.