In this issue:
(click the bookmarked links below to move to specific sections of this report)
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
Canola crop development in many areas is progressing slowly due to the cool weather and precipitation received this past week. Many areas (except for southwestern Manitoba) received from 5 to 75 mm of rain this past week. Some areas in northwestern Saskatchewan near Maidstone and east central Alberta near Hardisty received much larger amounts approaching 175 mm. Swathing of early seeded canola continues slowly in northern and western Saskatchewan and most of Alberta north of Hwy. 1. However, areas of southwestern Manitoba and southeastern Saskatchewan are up to 90% swathed. Some combining of early seeded canola has occurred in southwestern Manitoba, southwestern Saskatchewan and southeastern Alberta. Reports continue of pod abortion and shallow pod depth caused by high temperatures and lack of rainfall in July and early August. These conditions will likely reduce yields compared to the amount of biomass produced. Normally, these lower levels of soil moisture are not a problem, but the generally shallow root systems of many of this year’s canola crops have predisposed the canola to moisture stress.
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 and soil moisture map from Saskatchewan Agriculture, Food & Rural Revitalization is available at:
http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt050828.pdf
Although there were no reports of frost this past week, damage from earlier cases of freezing temperatures is being noted, especially in parts of the Peace region including the Fairview-Hines Creek area. Please refer to the previous Canola Watch report (http://www.canola-council.org/seed/canola-watch/watch05-aug24.shtml) for a discussion on canola crop management after a frost.
Bertha armyworm activity has slowed considerably but continues to be noted on late seeded fields near Viking, Wainwright and Lloydminster, AB and stretches eastward toward North Battleford, SK. Remember to use appropriate thresholds before deciding on an insecticide application. The lower the canola price, the higher the appropriate threshold for treatment. Use the following link from MAFRI to assist in calculating the appropriate threshold: http://www.gov.mb.ca/agriculture/news/insect/miu05_08_15.shtml
If numbers are exceeding threshold levels and an insecticide treatment is needed, be sure to choose a registered insecticide with an appropriate pre-harvest interval. This is especially true for canola that needs more than one insecticide application and/or is close to reaching maturity. Do not jeopardize your farm’s revenue and Canada’s reputation by taking short cuts! As crops reach maturity, the pods become drier and tougher and less appetizing to insects. Crops that are swathed will dry down further, thereby making them even less appealing for insect feeding.
For fields that are either currently being swathed or have been swathed very recently, post-swathing scouting can be very useful, particularly if plants have developed poorly or ripened prematurely. Also, watch for abnormal areas that have wilted, or for prematurely ripening plants within canola stands that are otherwise healthy.
It’s an opportune time to add valuable information to the farm records that may influence some decision making in the upcoming season. Be on the lookout for weeds, insects and disease incidence. Fall weed identification can help you plan weed control next spring.
This is also a critical time for insect pressure and may give an indication of future pressures. For example, high flea beetle numbers this fall may indicate similar pressures next spring. As a result, consider seed treatments with extended flea beetle control.
Scouting for disease is also very important during this time. The cut stubble allows for an accurate assessment of diseases such as fusarium wilt, sclerotinia, blackleg and clubroot that restrict water and nutrient uptake by plants. Proper identification and assessment of disease incidence may be valuable information for assessing potential risk in next year’s crop.
Alternaria black spot continues to be found in canola crops across the prairies and is at higher levels in western regions of Manitoba and north-central Alberta near St. Albert, Morinville and Smoky Lake. Crops with black spot lesions covering a large proportion of pod surfaces are at increased risk for shattering and are poor candidates for delayed swathing or straight combining. For more information on Alternaria black spot refer to the following link:
http://www.canola-council.org/alternariasymptoms.aspx
New strains of blackleg have been found in Manitoba and eastern Saskatchewan in recent years. Efforts are being made to determine the occurrence and prevalence of these new strains. Growers who notice elevated blackleg levels in MR and R rated varieties are encouraged to collect samples and have them tested to determine what strain is present. Interested growers should e-mail Dr. Dilantha Fernando at d_fernando@umanitoba.ca for sampling and shipping instructions.
Clubroot has been found in fields northwest of Edmonton near St. Albert, Legal and Bon Accord. Some of these fields have high levels of infection. Although there is nothing that can be done for these infected crops, growers should employ recommended field sanitary procedures including thorough cleaning of soil and plant residues from equipment to reduce transfer of contaminated material from infected fields to other fields. Avoid using straw from infected fields. For more information on diagnosing clubroot and a discussion on management practices, refer to the following factsheet from AAFRD: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex8593
Last year, time of swathing recommendations were 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 and dry, avoid swathing. Swath during cool evening hours, at night or early in the morning to allow plants to dry down at a slower rate. This reduces the chance of green seed.
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. 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. A better strategy than swathing early to capture more yield 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 website: http://www.canola-council.org/pub_swathing.shtml
In normal years, the optimum stage to swath for both yield and quality is up to 60% seed colour change on the main stem. However, as the season progresses there are an increasing 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 and if a frost is likely. 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. Growers considering early swathing to avoid or reduce green seed levels from frost need to remember that swathing prior to 15-20% seed colour change will likely lose some yield potential. Also, the canola has to dry down sufficiently to reduce freezing damage and the canola may need to be swathed for several days before this stage is reached, especially if conditions are cool and damp.
Remember that under cool and wet conditions, swath curing will take longer than usual. Expect to have the crop in the swath for at least three weeks to allow for curing and as much de-greening as possible before combining. It is important to utilize swath rollers to anchor the swaths into the remaining stubble in order to limit the potential for wind damage to the swaths. However, growers are encouraged to avoid excessive packing from swath rollers, allowing as much air movement through the swath as possible to facilitate curing and limit disease spread in the swath.
There continue to be many questions regarding swathing timing for canola fields with variable growth caused by uneven emergence or stress from early season flooding. As well, some areas that had flooding damage earlier in the season are re-flowering. Growers should assess where the majority of their yield will come from and manage accordingly. If the majority of the field is still green, swathing should start when adequate seed colour change occurs in these areas. In fields where green and mature areas are more equal in size, be sure that seeds in the green areas are firm and no longer translucent. Swathing should be delayed as long as possible to allow for seed colour change to start in the green areas. However, in areas that still have plants that are flowering, ignore these plants at this time as these plants are unlikely to produce decent quality seed. To minimize losses in the ripe areas, growers should consider swathing in the evening or early morning.
Growers still considering straight cutting their canola this year should keep in mind the following factors:
Crop Canopy – the crop should be well knitted and slightly lodged to reduce the chance of pod shelling and pod drop. Remember that pod integrity (including petiole strength which influences pod drop) can be affected by frost.
Disease – the crop should be relatively free from diseases including blackleg, fusarium wilt, sclerotinia and alternaria. These diseases can cause premature ripening, which can in turn cause pod shattering.
Hail - crops affected by hail are poor candidates for straight cutting due to the probability of greater disease infection through damaged tissue and reduced pod integrity from physical damage. Also, any late season hail often causes greater levels of damage to standing crops than swathed crops.
Frost – crops left standing will be vulnerable to frost damage as long as the seed moisture is high. Therefore, late maturing fields will likely be poor candidates for straight cutting.
Send questions regarding this report to John Mayko, Agronomic Research & Extension Manager with the Canola Council of Canada at maykoj@canola-council.org ph/fax: 780-764-2593.
Direct specific questions regarding regional issues to 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 & Rural Initiatives,
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
Matthew Stanford, Agronomist, Southern Alberta,
stanfordm@canola-council.org, 403-758-6660
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.
« back