In this issue (click the bookmark
links below to move to specific sections of this
report):
Crop development
| Flower blast
| Insects | Sclerotinia
| Fusarium wilt
| Field scouting
| Swathing | Pre-harvest
glyphosate
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 remains varied across most of
the Prairies. Manitoba continues to be divided
between the late seeded fields still blooming
to the earlier fields at the end of flower to
full pod development. Most areas in Saskatchewan
are at the end of bloom and entering pod development
with the exception of late seeded fields, which
are still in full bloom. Most areas of Alberta
are in the pod development stage with the odd
field that is nearing the end of bloom whereas
southern Alberta and Polish varieties in the Peace
have ripened. The B.C. Peace region is experiencing
a second flush of flowers after moisture this
past week. Recent rains and cool temperatures
have slowed the crop development in most areas
of Saskatchewan and Manitoba, and crops are currently
2-3 weeks behind compared to the 2003 crop year.
Thundershowers were also reported in Saskatchewan,
central Alberta and the Peace regions. Soil moisture
conditions are improving in the dry areas of the
north and B.C. Peace and are becoming excessive
in central and eastern areas of the Peace with
heavier soils. A dry area remains in central Saskatchewan
where yield may be impacted.
For current moisture condition maps across western
Canada, visit this PFRA page:
http://www.agr.gc.ca/pfra/drought/drprec7_e.htm
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/crprpt040802.pdf
Additional moisture information for Alberta is
available from Alberta Environment at:
http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf
Cooler
temperatures this past week across the prairies
will have reduced the risk of flower blast
and poor pod development. However, areas where
the canola is still blooming (Manitoba and Saskatchewan)
may still be at some risk if the temperature increases.
Air temperatures in excess of 30°C
during flowering can result in flower abortion
and reduced pod formation, and gaps (no pod formation)
on the main stem. Hail, lack of available sulphur
or insect feeding (for example, lygus bugs and
cabbage seedpod weevils) may also result in gaps
on the main stem. More information is available
in the Canola Growers Manual in Chapter 5 pages
506 and 507.
Check
this Canola Council page for a photo of flower
blast.
Spraying for bertha armyworm larvae continues in the central Peace near Wanham and Eaglesham. Counts vary from 10 to 200 larvae/m2 with the majority of the fields around 30-larvae/m2. Low levels of insect activity are being reported in most areas. Striped flea beetles are being found in the Fairview area of the Peace region, mainly on canola fields that were not sprayed with an insecticide this spring. Although no economic thresholds exist for fall populations, use the fall flea beetle numbers as an indicator of potential risk for the upcoming season. Grasshopper activity is increasing in parts of Manitoba, southern Alberta and the northern B.C. Peace region where spraying of field margins is taking place. Low levels of lygus bugs continue to be reported in Saskatchewan and Alberta, but no chemical control has been reported. However, it is very important to keep scouting for these insects as the crop finishes flowering and starts podding. It is at the early podding stage that the crop is most vulnerable to economic losses from these insects. It is also important to use proper techniques when scouting for various insects. Use a sweep net to determine thresholds for lygus. Economic thresholds may vary from 30 to 50 lygus in a 10-sweep sample. However, be aware of the lygus stage. If a large number of nymphs are very small (aphid-sized), wait a week and sample again. The larger the lygus, the higher the potential damage. Also sample in the good areas of the field as higher numbers will be found in poor or thin areas. ‘Sap spots’ are also a good indicator of lygus damage. A sweep net cannot be used for determining thresholds for diamondback moth, bertha armyworm, beet webworm or alfalfa looper larvae. An estimation of the number of these larvae within a square meter is a more accurate method of determining thresholds for these insects.
For more background information
on bertha armyworm moth monitoring, check this
AAFRD sample map and discussion of how to interpret
the moth counts:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2526?opendocument
The current bertha armyworm moth map can be found
at:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2526?opendocument
For current trap count information in Saskatchewan,
visit this page:
http://www.agr.gov.sk.ca/docs/crops/
integrated_pest_management/insects/berthamap0107.asp
Fusarium
wilt has been reported in fields near Vegreville,
AB. For more information on identifying fusarium
wilt, visit this page:
http://www.canola-council.org/fusarium.aspx
As the crop is nearing pod development, be vigilant in the frequency and intensity of field scouting. Watch for abnormal areas that have wilted or prematurely ripening plants within canola stands that are otherwise healthy. These areas may be early signs of diseases such as fusarium wilt, blackleg and clubroot that restrict water uptake by plants. When scouting fields be aware of what is causing the damage and be sure to properly document the information for future reference and decision making aides. Scout for insects and diseases and nutrient deficiencies since these will become more evident as the crop matures. Pay close attention to misses, corners and overlaps or check strips to help determine if your fertility plan worked, and to help make important fertility decisions in the upcoming season.
Sclerotinia
continues to be reported in Manitoba, Saskatchewan
and southern and central Alberta.
Refer to the sclerotinia
checklist in the new Canola Growers Manual.
To assist in assessing the crop for the proper
bloom stage for fungicide application, check to
the following BASF page:
http://www.agsolutions.ca/basf/agprocan/agsolutions/WebASLibrary.nsf/CropProductionWest?OpenView
For the current list of recommended fungicides
for sclerotinia control, check the 2006 Crop Protection
Guide:
http://www.agr.gov.sk.ca/Docs/crops/CropProtGuideAddendum2006.pdf
For assistance in identifying diseased plants,
refer to the following page:
http://www.canola-council.org/sclerotiniasymptoms.aspx
Swathing
has started in southern Alberta and southwestern
Saskatchewan on Argentine canola and on Polish
canola in the Peace region. All other areas are
1-3 weeks from swathing. In the past year, time
of swathing recommendations have been changed
to reflect research results obtained after several
years of Canola Production Centre trials. 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. This widens the "swathing days"
window for all growers, including those with large
canola acreages. When conditions are hot (30°C)
and dry, avoid swathing. Swath during the cool
evening hours, at night or early morning to allow
plants to dry down at a slower rate. This reduces
the chance of green seed. If conditions are cool
and it is late August or early September and frost
is forecasted, consider swathing as early as 10%
seed colour change to minimize green seed. Refer
to the following risk maps for the average date
for fall frosts in Manitoba:
http://www.gov.mb.ca/agriculture/climate/waa50s00fig5.html
http://www.gov.mb.ca/agriculture/climate/waa50s00fig6.html
http://www.gov.mb.ca/agriculture/climate/waa50s00fig7.html
The colour of mature plants and pods will vary between varieties as they mature. Some will appear ripe on the outside before the seeds are mature. Seed colour is more important than the overall plant/pod colour when determining the stage of maturity. When field topography, soil type and soil moisture levels are uneven, the flat areas of the field may have 30% seed colour change, hilltops 70%, and low lying areas 5% seed colour change. This will make the decision of when to swath more difficult. Also, be conscious of sclerotinia infected fields and do not let the premature ripening of the diseased plants influence the timing of swathing. Realise that the bulk of the yield is still coming from the healthy plants and a better strategy to capture more yield than swathing early is to swath during dew periods to prevent shattering. To learn more about proper field assessment, refer to the revised Canola Council publication "Canola Time of Swathing Guide" or visit the Canola Council page.
With swath stage approaching, growers should consider a valuable weed control tool for next year's crop--pre-harvest glyphosate. It is the most consistent and effective treatment for many perennial weed problems, 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. Here’s the level of weed control the year after pre-harvest glyphosate for several perennial weed species:
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 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 seed crops.
Direct questions regarding this overall report
to Christine Mardell, Agronomist, Peace River
Region with the Canola Council of Canada at mardellc@canola-council.org
or ph:780-518-1513 or fax:780-402-3937
For specific questions regarding
regional issues associated with this report, consult
one of the following Canola Council of Canada
regional agronomists or provincial oilseed specialists;
For specific questions regarding regional issues associated with this report, please consult one of the following Canola Council of Canada regional agronomists or provincial oilseed specialists;
Derwyn Hammond, Agronomist,
Manitoba,
hammondd@canola-council.org,
204-729-9011
Rob Park, Manitoba Agriculture
& Food,
rpark@gov.mb.ca,
204-745-5665
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
Bill Greuel, Saskatchewan Agriculture,
Food & Rural Revitalization,
wgreuel@agr.gov.sk.ca,
306-787-2756
Doug Moisey, Agronomist, Central
Alberta,
moiseyd@canola-council.org,
780-645-3624
Christine Mardell, Agronomist,
Peace River Region,
mardellc@canola-council.org,
780-518-1513
Nancy Muchka-Dahl, Agronomist,
Southern Alberta,
muchkan@canola-council.org,,
403-625-3406
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@gems9.gov.bc.ca,
250-787-3213
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; Cargill; 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.