In this issue (click the bookmark
links below to move to specific sections of this
report):
Crop development
| Frost | Time
of swathing related to frost | Time
of swathing related to early planted canola
| Insects | Sclerotinia
| 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 variable across most of
the Prairies. Cool weather continued to slow crop
development. In Manitoba, some swathing of early
seeded fields has started, but overall swathing
progress is less than 10%. Swathing progress in
Saskatchewan is less than 5% overall, but up to
60% complete in the Swift Current area. Swathing
in Alberta ranges from virtually complete for
the irrigated area of the south up to just about
starting in the Edmonton area. Overall crop development
in western Canada ranges from several days to
three weeks behind normal, with the delay increasing
from west to east. Most areas received rainfall
over the past week ranging from a trace up to
2".
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/crprpt040823.pdf
Additional moisture information for Alberta is
available from Alberta Environment at:
http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf
Widespread
frost was reported across much of Saskatchewan
(other than the southwest) and Manitoba late last
week. As well, early last week, frost was reported
in Alberta near Bonnyville and Vermilion. Damage
assessment 3-4 days after the frost indicates
damage ranges from very light to severe, although
in many cases the cool and wet conditions delayed
the appearance of symptoms. In Manitoba, the area
enclosed in a triangle ranging from Russell/Roblin
in the northwest, southeast to Killarney and west
to the Saskatchewan border reports the most damage.
In Saskatchewan, some of the hardest hit areas
include Broadview, Kelvington, Lintlaw, Lestock,
Cupar and Wadena. The amount of frost damage is
dependent on various factors including crop stage,
degree and length of frost, relative humidity,
and presence of rain or dew. For a more detailed
discussion on the effects of frost, refer to the
following SAFRR link:
http://www.agr.gov.sk.ca/docs/crops/frostdamage.pdf
The recent frosts have raised many questions regarding the time of swathing as it relates to the frost damage. In normal years, the optimum stage to swath for both yield and quality is up to 60% seed colour change. However, the early frosts and abnormally cool weather may have altered the decision making process. The condition of the frost affected areas fall into three main categories, with appropriate swathing strategies for each category. Carefully access each field and note which scenario the majority of the plants fall into.
Scenario 1: when there is little evidence of frost damage. The pods remain mostly green or tan-green, with few, if any, white spots on the outside of the pods. The seeds inside are mostly intact. Check the colour of the inside of the seeds as well. If the outside of the seeds are starting to turn, the insides should be yellow or a light lime-green. If seeds are still green on the outside and the inside of the seeds are still watery, the outside seed coats should remain intact and turgid. In these cases, leave the crop to continue to mature until further seed and or pod colour change occurs.
Scenario 2: when there is considerable
whitening of the outside of the pods for a majority
of the plants.
In this case, the pods will begin to shrink and
desiccate rapidly, and swathing should begin immediately
to reduce pod shelling and pod drop and conserve
any seeds in those pods.
Scenario 3: when there are
only white specks on the outside of the pods,
or only a few seeds in immature pods are not intact,
or only a few seeds in the upper plant parts are
prematurely browning.
Premature browning occurs when the outside of
the seeds have been damaged by the frost and the
insides of the seed remains dark green. In these
cases, the fields should be left and monitored
on a daily basis to evaluate further crop changes.
If no further damage is evident, the remaining
crop may continue to fill and mature. If the seeds
continue to deteriorate and/or pod integrity declines,
begin swathing to conserve seed volume.
In all cases, monitoring should be done on a daily or bi-daily basis to evaluate further crop development and conditions, especially if warmer temperatures and sunshine return.
Also, there have been a number of reports of crops that were planted early (late April or early May) where the seeds are all firm and intact for a week or longer, but little to no seed colour change has taken place. These fields may be good candidates to begin swathing (as early as 10% seed colour change), especially if the short-term weather forecast remains cool and/or cloudy. In many of these cases, the crops have been in the ground for up to 120 days and the seeds may be physiologically mature, although outside seed colour remains green
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.
Spraying
for bertha armyworm larvae continues in
the central Peace near Wanham and Eaglesham and
in central Alberta near Vermilion. Flea beetles
continue to be reported from southwestern Manitoba.
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 has been reported
in western Manitoba near Virden, but ample supplies
of grass and cereals should keep damage to canola
to a minimum.
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
Sclerotinia
continues to be reported in Manitoba, Saskatchewan
and southern and central Alberta. For assistance
in identifying diseased plants, refer to the following
page:
http://www.canola-council.org/sclerotiniasymptoms.aspx
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. 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.
There are some questions regarding the use of Reglone or glyphosate to speed up and even out crop development. Remember that application of either product results in eventual killing of the plant. Application of either product too early will cause similar problems to swathing too early, with the additional possibility of increased herbicide residues in the crop. Be diligent in following label directions with regards to timing of product application.
Direct questions regarding this overall report
to John Mayko, Agronomic Research & Extension
Manager with the Canola Council of Canada at maykoj@canola-council.org
or ph/fax: 780-764-2593.
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.