#18 Western Canada – August 29, 2007
In this issue:
Harvest progress slowed by cooler weather
Frost may have damaged some canola crops
Wait a few days to assess frost damage
Late season diseases showing up
Growers asked to report new blackleg strains
Scout often to check for crop disease
Assess seed colour change before swathing
Avoid swathing when seeds are translucent and watery
Swathing early to avoid frost?
Assess crop conditions before deciding to straight cut
Straight cutting tips
Reduce risk of wind blown swaths
Fungus feeders found in freshly harvested canola
Use diatomaceous earth products correctly
Keep malathion far away from canola bins
Keep stored canola cool and dry
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
Harvest is progressing slowly in many areas due to the generally cool weather and precipitation of this past week. Swathing is just getting started in parts of west-central Alberta and the Peace region, whereas combining is up to 60% done in parts of central and eastern Manitoba. Cool weather continues to delay maturity and seed colour change in standing crops and rain delays continue to limit combining progress in many areas. Most regions received some moisture and a continuation of cooler temperatures last week, with rainfall amounts ranging from a trace to over 60 mm. Hail was reported in some areas of central and eastern Manitoba as well as across many areas of western and east-central Saskatchewan.
An overview of prairie vegetation conditions is available at (use the “start the prairies application” button on the left hand side): http://www26.statcan.ca/ccap/ccaphome_en.jsp
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/crprpt070825.asp
The most recent crop report from Alberta Agriculture and Food is available at:
http://www.gov.ab.ca/acn/200708/219388E83E90E-E64B-1ADF-29551428876161F9.html
For current maps of moisture conditions from PFRA, check the following links for precipitation since September 1 and April 1 respectively:
http://www.agr.gc.ca/pfra/drought/prpay07_e.htm
http://www.agr.gc.ca/pfra/drought/prpgs07_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
Frost was reported this past week in many areas of western Saskatchewan including Meadow Lake, Leask, Battleford, Biggar and Herschel, as well as central Alberta and the Peace region. Although the frost damage was light in many areas, some low lying areas likely experienced more damage. Frost damage evidence was reported from the Quill Lake region of Saskatchewan which experienced a frost about two weeks ago.
Wait a few days to accurately determine frost damage. To determine when to swath frost damaged canola, check the extent of damage 2-3 days after the frost. The condition of frost affected areas will likely fall into one of three main categories, with appropriate swathing strategies for each category. Carefully assess each field and note which scenario the majority of the plants falls into.
Scenario 1: 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 are mostly intact. Check the colour of the inside of the seeds as well. If the outsides of the seeds are turning brown, the insides should be yellow or a light lime-green. If seeds are still green on the outside and the insides of the seeds are still watery, the outside seed coats should remain intact and turgid. In these cases, leave the crop to mature until enough seed colour change occurs.
Scenario 2: There are only white specks on the outside of the pods; 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 seed has been damaged by the frost and the inside of the seed remains dark green. Check the following link for a photo of moderate crop damage, including premature browning of seed vs. normal seed:
http://www.canola-council.org/production/Frost/frost.html
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.
Scenario 3: There is considerable whitening of the outside of the pods on most of the plants. Check the previous link for a photo of severe crop damage. In this case, the pods will begin to shrink and desiccate rapidly, and swathing should begin immediately using the dew to reduce pod shelling and pod drop to conserve seeds. In all cases, monitoring should be done daily or every other day to evaluate further crop development and conditions, especially if warmer temperatures and sunshine return.
For more information on assessing frost damaged canola refer to the following links: http://www.canola-council.org/PDF/sept20_canola_fact_sheet_r3.pdf
http://www.agr.gov.sk.ca/docs/production/frost_greenseed.asp
Reports of late season diseases continue, including: high levels of sclerotinia in untreated fields in parts of Manitoba, northern Saskatchewan, central Alberta and the B.C. Peace; aster yellows across all areas; clubroot around Edmonton, Leduc and St. Albert, AB; alternaria in northwestern SK and north central AB; and fusarium wilt and blackleg in south central MB. Fields that received hail damage appear to be more prone to secondary disease development. Although there is nothing that can be done at this point in the season, records of disease incidence can assist in rotation and other management decisions for next year.
To keep track of new strains of blackleg, 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 fernando@cc.umanitoba.ca for sampling and shipping instructions.
During fall scouting for proper swath timing, watch for abnormal areas that have wilted or for prematurely ripening plants within canola stands that are otherwise healthy. Post swathing (within approximately 3 days after swathing) is another ideal time for disease scouting. Prematurely ripening areas may be indicators of diseases that restrict water and nutrient uptake by plants. It is important to accurately identify what is causing the damage and properly document the information for future reference. Identification of clubroot will allow growers to take steps to limit soil (and associated spore) movement to other fields through equipment sanitation. Fields with alternaria will be poor candidates for delayed swathing and should not be straight combined as pods will be prone to shattering.
The hot and dry weather earlier this summer has caused purpling and premature plant colour change in many canola fields. This is a relatively normal response to stress and growers need to ensure that seed colour change is occurring when they assess the proper time to swath. The colour of mature plants and pods will vary among varieties. Some will appear ripe on the outside before the seeds are mature, so avoid using plant colour as a gauge to proper timing. Open up pods on the main stem and look at the colour of the seeds to accurately assess swathing timing.
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. Avoid swathing when a significant portion of the seed in the top pods and side branches remain translucent and watery. 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.html
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 where the seeds are all firm and intact for a week or longer, but little to no seed colour change has taken place. If the short-term weather forecast remains cool and/or cloudy with a high risk of frost then it may be better to begin swathing these fields as early as 10% seed colour change. The risk of yield loss from early swathing will be reduced if all the seed is firm, but the risk of grade loss from frost damage if the crop is left standing is relatively high. 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.
More growers are considering straight cutting their canola this year. To be successful, consider 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 and drought.
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.
Straight cutting has been successfully done with all types of headers, but most consistent success has come from the use of flex headers or rigid headers with extensions such as the Biso header attachment. Draper headers can also work well, but take care with the transition areas from the drapers to the feeder house, as gaps in these areas can allow for seed loss to occur. With any headers, adjust the reel as far back as possible, so that any seed shattered by the reel has a chance of being recovered by the table below. Adjust reel speed to match ground speed and keep the reel as high as possible to reduce the chances of shattering seed. Combine as soon as crop condition will allow. This will reduce the time the crop is prone to damage in the field. As a result the crop may be tough or damp, especially if no preharvest glyphosate or desiccant was used. This will likely require more threshing power as well as increase the moisture content of the seed. Ensure that adequate aeration or drying facilities are available to condition the crop properly for storage.
There were more reports of wind blown swaths this week. Usually the worst affected fields were swathed at right angles to prevailing winds. Growers with fields still to swath are encouraged to swath their fields parallel to prevailing winds to reduce the risk of wind blown swaths and resulting crop loss from shelling. Cut as high as possible (just below the lowest pods) and consider using a swath roller to help anchor the swath into the stubble.
There are reports from parts of central and western Saskatchewan regarding insects in newly harvested canola. Although there were concerns that these insects were rusty grain beetles, initial reports indicate that these insects are fungus feeders not rusty grain beetle. These beetles feed on fungus that grows on crop residue or damp seeds. Fungus feeding insects and mites cannot survive in dry grain. Chemical control is not necessary for fungus feeding pests in stored grain. Do not apply malathion or other chemical insecticides to your canola. Conditioning grain to ensure that it is dry and cool should be all that is needed to control such pests. Information to help identify and control insect pests of stored grain can be found at the following links: http://res2.agr.ca/winnipeg/storage/pages/princ_e.htm
http://www.gov.mb.ca/agriculture/crops/cropproduction/faa06s00.html
There have been some questions from growers wondering about mixing diatomaceous earth products such as “Protect-It’ or ‘Insecto’ into their canola for insect control. These products should only be used to treat bin floors and walls prior to storing grain, as they are not registered for use on stored canola. Proper conditioning of the grain to “dry” moisture content and cool temperatures should be all that is required to control these fungus feeders.
At this time of the year, as growers prepare bins for storage, it is important to note that oilseed crops including canola can absorb malathion from bin surfaces, and the resulting residues have been found in crop delivered to elevators. Therefore, Do NOT use malathion to treat bins destined to store canola from the upcoming harvest. Refer to the following link for further information: http://www.canola-council.org/pesticide_link2.html
For those growers combining canola during warm temperatures, canola storage can also be a concern even at seed moisture levels of 8% or lower. This can be compounded by the presence of insects such as grasshoppers and ladybugs in the grain. 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, chaff or insects. Use aeration to bring down the temperature of the binned canola. For more information on safe storage and conditioning canola, check the following link: http://www.canola-council.org/media_aug2306.html.
Direct questions regarding this report to John Mayko, Senior Agronomy Specialist, Parkland West (West Central AB), 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 agronomy specialists or provincial oilseed specialists:
Derwyn Hammond, Agronomy Specialist, Manitoba, hammondd@canola-council.org, 204-729-9011
Arvel Lawson, Manitoba Agriculture, Food & Rural Initiatives, Arvel.Lawson@gov.mb.ca, 204-745-0340
David Vanthuyne, Agronomy Specialist, Eastern Saskatchewan, vanthuyd@canola-council.org, 306-946-3588
Jim Bessel, Senior Agronomy Specialist, North-central/eastern Saskatchewan, besselj@canola-council.org, 306-373-6771
Penny Pearse/Scott Hartley, Saskatchewan Agriculture, Food & Rural Revitalization, ppearse@agr.gov.sk.ca / shartley@agr.gov.sk.ca , 306-787-4671 / 306-787-4669
Doug Moisey, Agronomy Specialist, Parkland East (East Central AB & NW SK), moiseyd@canola-council.org, 780-645-3624
Matthew Stanford, Agronomy Specialist, Chinook (Southern AB & SW SK), stanfordm@canola-council.org, 403-758-6660
Anne Vos, Acting Agronomy Specialist, Peace Region, av@summit-ag.com, 780-835-4632
Murray Hartman, Alberta Agriculture, Food & Rural Development, murray.hartman@gov.ab.ca, 403-782-8024
Kerry Clark, BC Ministry of Agriculture and Lands, Kerry.Clark@gov.bc.ca, 250-784-2559
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; 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.