Soil moisture conditions remained dry throughout most areas of the prairies during the past week, with only scattered showers reported.
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
Additional moisture information for Manitoba is available from Manitoba Agriculture at:
http://www.gov.mb.ca/agriculture/news/
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 continued heat and dry conditions, with swathing under way in all regions. Swathing is nearly complete in southwestern Saskatchewan and eastern and southeastern Manitoba. Most other areas are at least 50% swathed. Central and north central Alberta and the Peace region remain the least advanced with swathing just getting under way. Combining of early swathed canola has begun in Manitoba, Saskatchewan and southern Alberta. 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 risk also remains 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 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. Smaller, less mature seed can also shrivel up, which can result in throw-over during combining and lost yield. Consider delaying swathing to ensure that the bulk of the crop has reached at least 30% SCC. This 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.
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. During recent hot weather, 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 continue to be a problem in many areas. Grasshoppers continue to damage crops as the hoppers move from ripe cereal crops into green canola fields. Diamondback moth larvae continue to be found in many areas, but not generally at threshold levels, except in pockets in eastern Alberta. High numbers of flea beetles continue to be found throughout much of Manitoba, Saskatchewan and southern Alberta, with some pod stripping occurring in southern Alberta.
As mentioned in earlier reports, 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
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 check the following link.
Under average weather conditions, canola can typically be ready to combine in 10 days to two weeks after swathing. This time period is normally required for the seed to properly cure and clear green seed. Under the hot, dry and windy conditions experienced in many areas, the crop may dry down much faster than normal. However, the chlorophyll in the seed may not have had a chance to clear adequately. Under these conditions, growers should consider leaving the crop in the swaths for a longer period of time to allow the chlorophyll to clear properly.
Direct overall questions regarding this report to John Mayko, Agronomic Research & Extension Manager, maykoj@canola-council.org, ph/fax: 780-764-2593.
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.