Canola Watch

2006 Canola Watch Reports

Canola Watch Report No. 13 Western Canada – July 19, 2006

In this issue:
(click the bookmarked 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 advance rapidly due to above normal temperatures across most regions. Development ranges from the full bloom stage for late seeded fields up to the fully podded stage for early seeded fields, and continues to be a function of seeding date in most areas. Some early seeded fields in central, eastern and Interlake regions of Manitoba appear to be within a week or so of being ready to swath. Soil moisture conditions continue to deteriorate in most areas due to the combination of lack of general rain plus the above normal temperatures. Only spotty thundershowers were received in most areas again this past week with the exception of the central and northern Peace regions which received between 1-4 inches of rain. Crops in the north Peace, southern Alberta and parts of northern Saskatchewan look good at this point, but most other areas are in need of decent rain soon to be able to salvage close to average yields.

For current maps of moisture conditions from PFRA for western Canada, check the following links for precipitation from September 1 to July 15 and April 1 to July 15 respectively:
http://www.agr.gc.ca/pfra/drought/prpay06_e.htm
http://www.agr.gc.ca/pfra/drought/prpgs06_e.htm
http://www.agr.gc.ca/pfra/drought/pa_e.htm

The latest crop report from Manitoba Agriculture, Food and Rural Initiatives is available at:
http://web2.gov.mb.ca/agriculture/mwcr/

The latest crop report from Saskatchewan Agriculture, Food & Rural Revitalization is available at:
http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt060716.pdf

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

Heat stress (plants wilting and sometimes taking on a bluish grey hue), blossom blasting (flower or pod abortion) and a shortened bloom period continue to be reported across western Canada. The most likely cause in these areas is drought and/or heat stress. 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 improve. For more information on heat stress check the following link: http://www.canola-council.org/temp_frost_hail.aspx 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

Although most of the heat stress symptoms described above are likely due to the warm temperatures, it is important to scout the affected areas to see if there may be some other underlying contributing factors such as root damage from root maggots or clubroot, or stem damage from blackleg.

Hail damage from isolated scattered thundershowers was reported in several areas including eastern Manitoba. Potential canola yield losses will depend on stage of crop and the severity of the damage. Hail damage can also allow points of entry for diseases such as sclerotinia stem rot, alternaria black spot and blackleg to infect canola plants. Further information is available at the following link: http://www.canola-council.org/stress_hail.aspx

Remember to keep scouting fields on a regular basis to detect 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 at later crop stages. Also, for more information and tips on late season scouting for both diseases and insects, view the following Canola Advantage press release at http://www.canola-council.org/media_jun1906.html

Bertha armyworm moth numbers continue to increase in traps placed in canola fields throughout western Canada. Cumulative counts have exceeded 1000 in areas of northwest Manitoba in the rural municipality of Swan River, Saskatchewan near Lemberg, Govan, Biggar, Birch Hills and Tisdale and Alberta near Milo and Vulcan. As well increasing numbers were noted in eastern Alberta near Vermilion and Wainwright, and in northwestern Saskatchewan around North Battleford, SK. Many areas are reporting emerging larvae with spraying occurring in the north Peace near Keg River. Growers in all traditional canola growing areas should be on the alert for this pest and watch for further information.

For more information on the bertha armyworm, refer to the following link:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2521

For interpreting bertha armyworm trap numbers, refer to the following link:
http://www.gov.mb.ca/agriculture/news/insect/bertha/interpret.html
Refer to the following links for the current bertha armyworm count maps:
http://www.agr.gov.sk.ca/docs/crops/integrated_pest_management/insects/Berthamap20060712.pdf (SK)
http://ncrxeis4.agr.gc.ca/ppmnMaps/20060713_bertha_armyworm_ab.pdf (AB-BC Peace)
http://ncrxeis4.agr.gc.ca/ppmnMaps/20060713_bertha_armyworm_mb.pdf (MB)
http://ncrxeis4.agr.gc.ca/ppmnMaps/20060713_bertha_armyworm_pr.pdf (Overall Prairies)

Proper identification of bertha armyworm larvae is important as they can be confused with other larvae. For more information regarding bertha armyworm identification, please refer to the Canola Scouting and Sweep Net Insect ID Card and the following links:
http://www.canola-council.org/bertha.aspx
http://www.canola-council.org/PDF/sweepcard_pgs_04.pdf#page=1

Although yields may have been impacted negatively by the heat and drought in many areas, use appropriate thresholds to determine whether control of bertha armyworm larvae is warranted (Table 1). The larvae will eat plant material in proportion to their populations and crops with a lower yield potential will suffer similar yield loss (in terms of bu/ac) to a higher yielding crop.

Table 1. Economic thresholds for bertha armyworm on Argentine canola. For example, assuming a crop price of $8.00 per bushel and a spraying cost of $9.00 per acre, the table indicates an economic threshold of 19 bertha armyworm larvae per square metre. Spraying would not be economical if larvae counts are less than 19 per square metre.

For more information on the proper timing of bertha armyworm control, refer to the following MAFRI link: http://www.gov.mb.ca/agriculture/news/insect/miu06_07_17.html

Refer to the following link for more information on monitoring and control of bertha armyworm:
http://www.canola-council.org/berthamonitoring.aspx

Some spraying for lygus bugs was noted in parts of eastern Manitoba. As well, lower levels of lygus were also reported in parts of northeastern Alberta. The threshold for lygus bugs can vary greatly, depending on the crop stage and commodity prices. For more information on lygus bugs check the following links: http://www.canola-council.org/lygusmonitoring.aspx. Ensure that appropriate thresholds are reached before considering insecticide application.

If a pesticide application is made to control any pests in-crop, ensure that appropriate pre-harvest intervals are followed. Pre-harvest interval refers to the time from application of product until the point at which the crop is cut (swathed or straight cut). Ensure that the appropriate preharvest interval is followed to eliminate chances of excess residues appearing in the resulting crop, and damaging markets.

Clubroot was noted in fields near St. Albert, AB, with one field reported to have virtually 100% infection. Although there is nothing that can be done to control the disease in-crop, following a proper rotation can lessen disease severity and proper equipment sanitation can assist in reducing the spread of this disease from field to field. For more information on clubroot, refer to the following AAFRD link: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex8593.

At this time of the year, growers are beginning to prepare their bins for storage of the upcoming harvest. It is important to note that malathion and other similar insecticides should not be used to treat grain bins for insects prior to storing canola. Although this practice is common for cereal crops, oilseed crops like canola can absorb the malathion from the bin surfaces and the resulting residues have been found in crop delivered to elevators. Therefore, DO NOT use malathion to treat bins destined to store canola from the upcoming harvest. Refer to the following link for further information: http://www.canola-council.org/pesticide_link2.html

The recent hot and dry weather has caused purpling and premature plant colour change in many canola fields. This is a relatively normal response to stress and growers need to ensure that seed colour change is occurring when assessing the proper time to swath. The colour of mature plants and pods will vary among varieties as they mature. Some will appear ripe on the outside before the seeds are mature, so avoid using plant colour as a gauge to proper timing. Open up pods on the main stem and look at the colour of the seeds to accurately assess swathing timing.

Recent research indicates that the optimum stage to swath for both yield and quality is up to 60% seed colour change. This enables many growers to start swathing at 30% to 40% seed colour change without sacrificing significant yield or quality. It widens the "swathing days" window for all growers, including those with large canola acreages. When conditions are hot and dry, avoid swathing. Swath during cool evening hours, at night or early in the morning to allow plants to dry down at a slower rate. This reduces the chance of green seed.

When assessing seed colour, also check seed firmness. Under cool conditions, seeds near the top of the plant may continue to fill and become firm before the lower seeds begin to turn colour. Also, be conscious of disease-infected or hail-damaged fields and do not let the premature ripening of the diseased or damaged plants influence the time of swathing. Realize that the bulk of the yield is likely still coming from the healthy plants. A better strategy than swathing early to capture more yield is to swath during dew periods to prevent shattering of the damaged plants. To learn more about proper field assessment, refer to the revised Canola Council publication "Canola Time of Swathing Guide" or visit the Canola Council website: http://www.canola-council.org/pub_swathing.html

With swath stage approaching, consider a valuable weed control tool for next year's crop--pre-harvest glyphosate. It's the most consistent and effective treatment for many perennial weeds, providing an effective and economical alternative to in-crop control options. In early fall, perennial weeds are moving nutrients down into roots and rhizomes to prepare for winter. This period is when they are most vulnerable to herbicide translocation to the roots and better control is possible.

If a Roundup Ready canola variety has been grown, a pre-harvest application will assist in some dry down of green weeds and offer perennial weed control, but it will not dry down the crop. Apply when the crop has 30% or less seed moisture content. At this stage, the pods are green to yellow and most seeds have turned from green to yellow or brown. Wait three full days (72 hours) after application before swathing to allow thorough translocation of the herbicide to ensure extended long-term weed control. Do not use pre-harvest glyphosate on canola crops grown for seed.

If applying any preharvest chemicals prior to harvest with ground rig sprayers, the use of crop dividers can reduce the amount of crop loss due to trampling and shattering. In addition, traveling back and forth in the direction of prevailing crop lean will further reduce losses.

There are a number of growers considering straight cutting their canola this year. To be successful, consider the following factors:

Crop Canopy - the crop should be well knitted and slightly lodged to reduce the chance of pod shelling and pod drop. Remember that pod integrity (including petiole strength which influences pod drop) can be affected by frost and drought.
Disease - the crop should be relatively free from diseases including blackleg, fusarium wilt, sclerotinia and alternaria. These diseases can cause premature ripening, which can in turn cause pod shattering.
Hail - Crops affected by hail are poor candidates for straight cutting due to the probability of greater disease infection through damaged tissue and reduced pod integrity from physical damage. Also, any late season hail often causes greater levels of damage to standing crops than swathed crops.

Direct 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 agronomists or provincial oilseed specialists:

Derwyn Hammond, Agronomist, Manitoba,
hammondd@canola-council.org, 204-729-9011

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

Penny Pearse/Scott Hartley, Saskatchewan Agriculture, Food & Rural Revitalization,
ppearse@agr.gov.sk.ca / shartley@agr.gov.sk.ca , 306-787-4671 / 306-787-4669

Doug Moisey, Agronomist, Central Alberta,
moiseyd@canola-council.org, 780-645-3624

Jackie Heck, Agronomist, Peace River Region,
heckj@canola-council.org, 780-853-5261

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@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:

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.

Register today for Biodiesel: Powered by Canola The Westin Calgary July 17 - 18, 2006


« back