In this issue (click the bookmark
links below to move to specific sections of this
report):
Crop development
| Frost
| Insects
| Fusarium wilt
| Sclerotinia
| Field scouting
| Swathing/Assessing seed colour change
| 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. Manitoba continued to experience
cool conditions this past week, which hampered
crop advancement. Some early seeded fields have
been swathed, but there are concerns that many
of these fields may have been swathed too early.
Many later seeded fields remain in the latter
half of the bloom stage. Most areas in Saskatchewan
are well into pod development, with only the odd
late seeded field still in bloom. Dry conditions
in central areas near Davidson and Watrous have
caused the crop to advance more rapidly. Some
swathing has started south of Regina near Yellow
Grass, but concerns remain that many of these
fields have been swathed too early. Overall, crop
development in Saskatchewan is rated at 10 to
21 days behind normal. Swathing is not expected
to become general for another 10 to 14 days. In
southern Alberta, swathing is quite general with
up to 30% complete. Combining is expected to begin
by the end of this week in some areas near Medicine
Hat. In central Alberta, pod development is advancing,
with only the odd late seeded field still in bloom.
General swathing is not expected for another 10
days. In the Peace, most areas report some swathing
of early seeded fields, with the Falher-High Prairie
area being slightly behind the rest of the Peace.
Many fields of Polish varieties have been swathed.
High temperatures in the Peace this past week
have advanced crop development rapidly. The varying
stages of crop development are complicating decisions
regarding time of swathing. Moisture remains adequate
to excessive across most areas, but dry areas
persist in parts of central Saskatchewan, east
central Alberta near Coronation and Hanna and
the north Peace.
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/crprpt040816.pdf
The latest monthly crop report from Alberta Agriculture,
Food & Rural Development is available at:
http://www.gov.ab.ca/acn/200408/
1693142EFA7B8-1E67-4461-B49D4EDFDF7B8E8B.html
Additional moisture information for Alberta is
available from Alberta Environment at:
http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf
Frost
has been reported in areas east of Vegreville,
AB. The amount of damage will depend on numerous
factors including the degree and length of frost,
relative humidity, presence of rain or dew, and
crop stage. Wait for several days before determining
the amount of damage, especially on the immature
seeds and pods. For more information on the impact
of frost, refer to the following link:
http://www.canola-council.org/stress_frost.aspx
Spraying for bertha armyworm larvae continues in the central Peace near Wanham and Eaglesham and in the north Peace near Lacrete. Flea beetles continue to be reported in the Fairview and Hines Creek areas of the Peace, as well as from Manitoba near Swan Lake, where some pod stripping has been reported. Although no economic thresholds exist for fall populations, use the fall flea beetle numbers as an indicator of potential risk for the upcoming season. If pod stripping becomes severe, increased shattering may result, so consider earlier swathing to reduce flea beetle feeding. Reducing insect damage may override potential yield losses from early swathing. Grasshopper activity has been reported in drier areas of western Saskatchewan where spraying of field margins has taken place. One case of diamondback moth larvae in the field margins has been reported near Andrew, Alberta. Increasing levels of lygus bugs (up to 10-20 per sweep) continue to be reported in southern Alberta and the Peace near Fairview. There are concerns about crop damage from lygus, but growers need to carefully assess crop stage before considering insecticide application. In some cases, there may not be an adequate pre-harvest interval for insecticide application, and growers may be better off to advance their time of swathing to reduce lygus damage. Use a sweep net to determine lygus pressure. 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. Firm seed will result in less damage than watery, immature seed. 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 if thresholds for these insects have been exceeded.
For more background information
on bertha armyworm moth monitoring, check this
AAFRD sample map and discussion of how to interpret
the moth counts at:
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/prm2521
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 as well as in Saskatchewan from Wadena to Kamsack.
Classic premature ripening symptoms have been
reported in some of the Saskatchewan incidences.
For more information on identifying fusarium wilt,
visit this page:
http://www.canola-council.org/fusarium.aspx
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
As the crop completes 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 indicators of diseases such as fusarium wilt, sclerotinia, blackleg and clubroot that restrict water and nutrient uptake by plants. When scouting fields, be aware of what is causing the damage and properly document the information for future reference and decision-making. Scout for insects, 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 the fertility plan worked, and to help make important fertility decisions in the upcoming season.
Although
swathing has started in southern Alberta
and southwestern Saskatchewan on Argentine canola,
and on Polish canola in the Peace region, most
other areas are 10 to 21 days from swathing. Premature
swathing has been reported in Manitoba, southern
Saskatchewan and southern Alberta. Although the
crop is behind in many areas and the risk of potential
frost damage increases with each passing day,
resist the urge to swath early. In the past year,
time of swathing recommendations have been changed
to reflect research results obtained after several
years of Canola Council 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. It 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,
it is late in the season, and frost is forecast,
consider swathing as early as 10% seed colour
change to minimize green seed. Refer to the following
link for more information on frost dates for various
locations:
http://www.canola-council.org/stress_frost.aspx
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 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. This type of field
would be a much better candidate for earlier swathing
than one where seed colour change is beginning
to occur on the lower pods, but seeds in the upper
pods and side branches remain mushy or translucent.
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 and a better strategy to capture more yield
than swathing early 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 page:
http://www.canola-council.org/pub_swathing.html
With swath stage approaching, consider a valuable weed control tool for next year’s crop--pre-harvest glyphosate. It’s the most consistent and effective treatment for many perennial weeds, 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.
There are some questions regarding the use of Reglone (diquat) or glyphosate to speed up and even out crop development. However, 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 for product application timing.
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.