Soil moisture
conditions remained dry throughout
many areas of the prairies during
the past week, with only scattered
showers reported. Significant rainfall
accumulations were limited to northwest
Saskatchewan where rainfall amounts
ranged from 7 to 125 mm (3/10 to 5"),
as well as eastern and northwest Manitoba
where as much as 60 mm (2.5")
was received. However, even in these
areas the rainfall was highly variable,
with the greatest accumulations limited
to relatively small areas. There was
also some hail associated with the
storms in northwestern Manitoba, in
the areas southwest of Dauphin, MB,
and between Russell and Binscarth,
MB.
For current PFRA maps of moisture
conditions, check these Web pages:
http://www.agr.gc.ca/pfra/drought/drprec4_e.htm
http://www.agr.gc.ca/pfra/drought/drprecw_e.htm
http://www.agr.gc.ca/pfra/drought/prgrowing_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
The latest crop
report from Saskatchewan Agriculture,
Food & Rural Revitalization is
available at:
http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt030622.asp
?firstPick=Reports&secondPick=Crop%20Report
Crop development in most areas has advanced significantly due to heat and dry conditions, with swathing under way in all regions. Swathing is most advanced in southwest Saskatchewan where it is nearly complete, and is nearing the halfway point in southwest and eastern Manitoba and southern Alberta. A few of the earliest maturing fields are already being combined in southern Alberta and eastern Manitoba. The Peace region remains the least advanced, with much of the crop still about two weeks away from swathing. The hot, dry weather continues to cause concern in most regions. These conditions may prevent pods from filling properly and may cause small seed size and reduced seed yield. The potential is also high for locking in green seed.
Typically, it has been recommended that swathing begin when the plant has reached approximately 20% seed colour change (SCC), with the majority of the crop being swathed at or near the recommended time for optimum seed yield and quality. This is when the average seed moisture content is 30-40%, or the whole plant has reached about 35% seed colour change (SCC). To learn more about proper field assessment please refer to the Canola Council publication "Time of Swathing Guide" or visit our Web site.
Under the current hot and dry conditions seed colour change can be rapid, changing as much as 10% or more per day. Following typical recommendations for stage of swathing may not be appropriate, since swathing in hot (high 20’s to 30oC temperatures), dry and windy conditions may stop chlorophyll clearing due to rapid desiccation of swaths. This may result in some green seed problems since the enzyme responsible for clearing the chlorophyll requires moisture. This smaller, less mature seed can also shrivel up, which can result in throw-over during combining and lost yield. Delaying swathing to ensure that the bulk of the crop has reached at least 30% SCC may help reduce potential yield and quality losses in these situations. Swath during the cool evening hours, at night, or early in the morning to allow the seed to dry down at a slower rate and further reduce the risk of both green seed and shattering losses.
Uneven crop maturity, either among plants or through increased branching due to lower plant densities, can make judging when to swath more difficult. Proper assessment of a field involves checking maturity in several areas, in order to determine not only the average maturity but also the proportion of plants at various growth stages. If a large proportion of the plants are at the same stage, time of swathing should be judged on the maturity of those plants. However, it may not be clear which plants will produce the majority of the yield. In this case waiting a few days after the most mature plants are ready to swath can allow less mature plants or branches to ripen, at least beyond the stage where the seed is still translucent. This will reduce the chances of green seed problems and yield losses.
As swathing approaches, keep in mind that seed colour change is very different from pod colour change. Over the past week, many fields have experienced sun scalding or pod bleaching that may cause the crop to appear mature. Insect damage and varietal differences will also contribute to the ripening appearance of canola fields. It is important not to be fooled by the colour of the straw and/or pods. Pods that appear ripe and ready to swath may still have green and translucent seeds. Conversely, pods that do not appear ripe may contain mature seeds that have changed colour. Walking fields and examining seeds within pods is the only way to truly assess crop maturity.
Insects reported in the past week include bertha armyworm larvae in southwestern Manitoba and other isolated areas with some insecticide applications reported in Manitoba. Grasshoppers continue to be a problem in many areas with spraying of canola reported in Manitoba and northwestern Saskatchewan, as the hoppers move from ripe cereal crops into green canola fields. Diamondback moth larvae are now being found in most areas, but not generally at threshold levels. High numbers of flea beetles have now emerged in areas throughout much of Manitoba, Saskatchewan and southern Alberta, with some spraying to prevent pod stripping in eastern Saskatchewan and the Interlake region of Manitoba. Other insects noted over the past week include beet webworm, lygus bug, aphid and cabbage seedpod weevil (southern Alberta).
As canola reaches
the final stages of pod ripening,
it is important to recognize that
the crop will become less susceptible
to yield loss from insects such as
flea beetles, beet webworm, lygus
bug, aphid and cabbage seedpod weevil.
However, insects such as bertha armyworm,
grasshopper and diamondback moth that
can chew large holes in pods or devour
them entirely can still be a threat.
If insecticide applications are being
considered at this stage, it is important
to be aware of the preharvest interval
for the product selected. The preharvest
interval is the number of days that
must pass between the last application
of a pesticide and harvest. Harvest
is the cutting of the crop or removal
of the seed from the plant. Under
this definition, harvest includes
direct combining, cutting (swathing)
or grazing; not picking up a crop
already in the swath or baling for
hay. Leaving a preharvest interval
ensures that residues in the plant
will not exceed the maximum residue
limit set by Health Canada. The preharvest
interval can range from seven to 60
days for foliar products registered
for use in canola. Check the label,
consult with a company representative,
or check the crop protection guide
to confirm if it is safe to use a
particular product. The canola insecticide
section of the crop protection guide
is available at:
http://www.gov.mb.ca/agriculture/crops/cropproduction/pdf/gcp2006/cpg2006insect.pdf
For more information
and images of the moth and larvae,
visit these Web pages:
http://vc55moths.topcities.com/imagearchive/pyralid/loxostegesticticalis.htm
http://www.canola-council.org/images_insects.html
Lygus bug, diamondback
moth and sweep net scouting:
http://www.canola-council.org/seed/canola-watch/watch-jun25.shtml
http://www.canola-council.org/PDF/sweepcard_04.pdf
http://www.canola.ab.ca/acpc/lygus.shtml
For more information on bertha armyworm including latest monitoring results, check the following links:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/prm2521
http://www.agr.gov.sk.ca/DOCS/crops/
integrated_pest_management/insects/Berthawo.asp
?firstPick=Crops&secondpick=Integrated%20Pest%20Management
&thirdpick=Insects
http://www.agr.gov.sk.ca/docs/crops/
integrated_pest_management/insects/berthamap0107.asp
?firstPick=Crops&secondpick=Integrated%20Pest%20Management
&thirdpick=Insects
http://www.gov.mb.ca/agriculture/crops/insects/fad03s00.html
Anyone scouting fields planted to a canola variety rated moderately resistant (MR) or resistant (R) who finds blackleg infected plants, is asked to send the infected plants to Dr. Dilantha Fernando. To submit a sample, cut the stem 2" on either side of the lesion, put the cutting in a paper bag (not a plastic bag) and mail it to: Dilantha Fernando, Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2. For more information, call him at 204-474-6072 or e-mail fernando@ms.umanitoba.ca. University researchers are studying the blackleg races present to determine whether any have been able to overcome the resistance in current varieties.
For those growers starting to combine canola in these warm temperatures, canola storage can also be a concern. Growers should be aware that canola binned at high temperatures may be susceptible to heating and spoilage even though it may test dry, particularly if it contains green material such as weed seeds or chaff. Aeration to bring down the temperature would be recommended. For more information on safe storage conditions click here.
Direct overall questions regarding this report to Derwyn Hammond, Agronomist – Manitoba, hammondd@canola-council.org, ph/fax: 204-729-9011.
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 Blais, Agronomist, Western Saskatchewan,
blaisd@canola-council.org,
306-895-2122
David Vanthuyne, Agronomist, Eastern
Saskatchewan, vanthuyd@canola-council.org,
306-782-7799
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 &
Southern Alberta, moiseyd@canola-council.org,
403-553-2829
Christine Mardell, Agronomist, Peace
River Region, mardellc@canola-council.org,
780-518-1513
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 Crop 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, James Richardson International, 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.