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 be ahead of normal in all regions due to hot and dry weather this season. The majority of the crop is well into podding with seed color change occurring in many fields. All areas report some swathing of early seeded fields but many do not anticipate general swathing for about one to two weeks. Swathing is most advanced in Manitoba (except for the northwest where swathing is just starting), southern Saskatchewan, southeastern Alberta and in the western Alberta Peace Region and B.C. Peace Region. There have been reports of some combining of early canola in central and eastern Manitoba, southwest Saskatchewan and south eastern Alberta. Soil moisture conditions continue to remain dry in many areas, but there was more rain again this past week with scattered showers in central and southern areas of the prairies to over an inch in parts of the Peace River Region, northern Saskatchewan and the Interlake and southeastern areas of Manitoba. Isolated but in some cases severe hail was reported south of Portage la Prairie and in the Interlake and eastern areas of Manitoba, and around Delisle and south and west of North Battleford in Saskatchewan.
For current maps of moisture conditions from PFRA for western Canada, check the following links for
precipitation from September 1, 2005 to August 7, 2006 and April 1 to August 7, 2006 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/crprpt060806.pdf
Additional moisture information for Alberta is available from Alberta Environment at:
http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf
Spraying for bertha armyworm larvae has subsided in areas with high moth trap numbers identified earlier throughout western Canada. Numerous acres were sprayed in areas of northwest Manitoba including the Swan River valley, Roblin and Russell and recently around Erickson, in Saskatchewan near Lemberg, Govan, Biggar, North Battleford, Rosthern, Birch Hills, Tisdale, Preeceville and Kamsack and in Alberta near Milo, Vulcan, Rockyford, Drumheller, Wainwright, Paradise Valley and Vermilion. High numbers (up to 10-15/ft2) have been found in some fields, but numbers and larvae stage vary widely from field to field.
In some areas, spraying for berthas has occurred but apparent poor control has been reported. The lack of control may be due to poor application (low water volumes or poor canopy penetration), very high numbers or poor timing. Remember that most insecticides will not achieve 100% control. In areas with very high numbers (10-15 ft2 or more), if one achieves 80% control, there still would remain 2-3 /ft2. Also, the moths laid their eggs over a period of time, therefore the larvae hatch over a similar period of time. Therefore, there may be more larvae emerging at later stages that were missed by the insecticide spray. Timing of application is also critical. It is important to ensure that the larvae are up on the middle to upper parts of the plant and feeding on the pods. If the larvae are still feeding on leaf material in the lower canopy or the leaf litter on the ground, there will be poorer control. Avoid spraying during high temperatures (above 25 degrees C), as the larvae are likely to be in the lower levels of the canopy. Also, use rates appropriate to the stage of the larvae. Most insecticides recommend a range of rates. Use higher rates when faced with high populations and/or larger stages.
Although spraying has subsided, many fields may still be at risk in the above mentioned areas. This most likely will be the case in later seeded fields where leaf material is just beginning to fall off. Frequent scouting for bertha armyworm is still critical to avoid significant yield loss. Scouting for larvae should occur in the cool parts of early morning or late evening when they are actively feeding. In crops with good vegetative growth remaining on the plant, the larvae will be found feeding on leaves in the lower part of the crop canopy. In crops where most of the leaves have fallen off, search for larvae under leaf litter on the ground, especially if scouting during hotter parts of the day. Although numbers may be high, if the larvae are at the lower canopy levels, insecticide application would be premature. However, once the larvae finish consuming the lower leaf material, they can move rapidly to the upper canopy and begin feeding on pods. Frequent scouting throughout the day is not unreasonable in these conditions and will enhance the effectiveness and timing of any required insecticide applications.
Due to the widespread bertha outbreak, availability and access to custom aerial applicators is at a premium. Growers must ensure that their crops and insects are at the proper stage before spraying. Spraying just because the plane is in the area is likely to achieve poor results. Although the use of high clearance ground sprayers will cause some losses from wheel tracking, timely and effective insecticide application may offset yield losses when compared to a poorly timed or staged aerial application. Ground sprayers will also allow for the use of higher water volumes and pressures that may enhance the effectiveness of the insecticide.
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/Berthamap20060726.pdf (SK)
http://ncrxeis4.agr.gc.ca/ppmnMaps/20060731_bertha_armyworm_ab.pdf (AB-BC Peace)
http://ncrxeis4.agr.gc.ca/ppmnMaps/20060731_bertha_armyworm_mb.pdf (MB)
http://ncrxeis4.agr.gc.ca/ppmnMaps/20060731_bertha_armyworm_pr.pdf (Overall Prairies)
Proper identification of bertha armyworm larvae is important as they can be confused with other larvae especially in their early development stages. 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/berthaidentification.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 $7.00 per bushel and a spraying cost of $10.00 per acre, the table indicates an economic threshold of 25 bertha armyworm larvae per square metre (approximately 2.3 larvae per square foot). Spraying would not be economical if larvae counts are less than 25 per square metre.
| Expected Seed Value - $/bushel | |||||||
| Spraying Cost - $/acre |
6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Number of Larvae/metre² | |||||||
| 7 | 20 | 17 | 15 | 13 | 12 | 11 | 10 |
| 8 | 23 | 20 | 17 | 15 | 14 | 13 | 11 |
| 9 | 26 | 22 | 19 | 17 | 16 | 14 | 13 |
| 10 | 29 | 25 | 22 | 19 | 17 | 16 | 14 |
| 11 | 32 | 27 | 24 | 21 | 19 | 17 | 16 |
| 12 | 34 | 30 | 26 | 23 | 21 | 19 | 17 |
For more information on the proper timing of bertha armyworm control and on how to determine appropriate thresholds, refer to the following MAFRI link:
http://www.gov.mb.ca/agriculture/news/insect/miu06_07_31.html
Refer to the following link for more information on monitoring and control of bertha armyworm:
http://www.canola-council.org/berthamonitoring.aspx
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. Refer to the following links for information on pre-harvest intervals for some common pesticides and description of the importance of following pre-harvest intervals:
http://www.canola-council.org/pre_harvest.html
http://www.canola-council.org/general_pesticide_link.html
For more information on registered insecticides for bertha armyworm control refer to the following links:
http://www.gov.mb.ca/agriculture/crops/cropproduction/gaa01d01.html
http://www.agr.gov.sk.ca/Docs/crops/cropguide00.asp
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 continues to cause purpling and premature plant colour change (click on link to last weeks' report for photo: (http://www.canola-council.org/Canola-Watch-Report-15.html ) in many canola fields, especially in the upper parts of the canopy exposed to the sun. 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. Refer to the following press release for more information on swathing in hot, dry weather:
http://www.canola-council.org/media_jul2606.html
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. Swathing at this time may also alleviate shatter losses from hail and bertha armyworm damage that many areas experienced this year.
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
As general swathing nears, there are many fields that have varying stages of maturity in them. Producers must estimate where the majority of the yield in the field will be. Swathing to avoid shatter loss on hill tops may not leave enough time for proper seed color change in greener low spots to occur. This may result in yield loss in the low spots where there is usually more yield.
Another valuable tool to consider as swathing approaches is the use of a pre-harvest glyphosate to control weeds for next years' crop. It's the most consistent and effective treatment for many perennial weeds, providing an effective and economical alternative to in-crop applications. Refer to last week's Canola Watch report for further comments on pre-harvest applications:
http://www.canola-council.org/seed/canola-watch/Canola-Watch-Report-14.html
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.
During fall scouting for proper swath timing and late insect scouting producers should watch for abnormal areas that have wilted, or for prematurely ripening plants within canola stands that are otherwise healthy. These areas may be indicators of diseases such as fusarium wilt, sclerotinia, blackleg and clubroot that restrict water and nutrient uptake by plants. It is important to accurately identify what is causing the damage and properly document the information for future reference and decision making.
New strains of blackleg have been found in Manitoba and eastern Saskatchewan in recent years. Efforts are being made to determine the occurrence and prevalence of these new strains. Growers who notice elevated blackleg levels in MR and R rated varieties and who would like to participate in the survey should collect samples and have them tested to determine what strain is present. Interested growers should e-mail Dr. Dilantha Fernando at d_fernando@umanitoba.ca for sampling and shipping instructions.
With combining starting in some areas it is important that the canola seed is
stored properly before marketing. Remember that freshly harvested canola seed
can respire for up to six weeks and can begin to develop moist and hot spots within the bin which
then cause the seed to heat. Canola should be stored in aeration bins whenever possible, and
should be below 15 degrees C and 8% moisture for longer term storage. Proper
conditioning will be critical for safe storage if harvesting conditions remain hot. Refer to the
following Canola Advantage press release for further information on canola storage:
http://www.canola-council.org/about-us/media-news/media-releases/media-aug2905.html
Direct questions regarding this report to David Blais, Agronomist, Western Saskatchewan,
blaisd@canola-council.org, 306-895-2122
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
Arvel Lawson, Manitoba Agriculture, Food & Rural Initiatives,
alawson@gov.mb.ca, 204-745-0340
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, 780-835-5261
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.