Crops and moisture conditions run the gamut

Crop development ranges from just past the full bloom stage for late seeded and reseeded crops to the pod stage with significant seed colour change for the earliest maturing fields. Canola is most advanced in parts of southern Manitoba, southwestern Saskatchewan and southern Alberta, where the earliest crops are at or within a few days of swathing. The rest of the crop is, on average, five to ten days behind and one to three weeks away from swathing.  However, above normal temperatures would hasten maturity.

Scattered and highly variable showers dropped trace to 75 mm of rain over the past week. Moisture conditions range from excessive in Manitoba (Ste. Rose and parts of the Interlake) to critically dry in the central and western areas of the Peace region. Many of the previously dry areas received moisture that has alleviated some stress, but accumulations were variable and some dry pockets remain.

For current maps of moisture conditions from the Prairie Farm Rehabilitation Administration (PFRA), check the following links: 

Since Sept. 1, 2007 - http://www.industrymailout.com/Industry/Redirect.aspx?u=113406&q=82918425&lm=11426940&r=106317&qz=4267706548dd0baf29d3578128ce9514

Since April 1, 2008 - http://www.industrymailout.com/Industry/Redirect.aspx?u=113407&q=82918425&lm=11426940&r=106317&qz=495bdb42d2961d49e188f879f93ce120

The latest crop report from Manitoba Agriculture, Food and Rural Initiatives (MAFRI) is available at: http://www.industrymailout.com/Industry/Redirect.aspx?u=113408&q=82918425&lm=11426940&r=106317&qz=ba515b3e0a47c6904136ba479c924c7d

The latest crop report from Saskatchewan Agriculture is available at:

http://www.industrymailout.com/Industry/Redirect.aspx?u=124025&q=82918425&lm=11426940&r=106317&qz=4ca42ebe0867720b93819dfc1f42ef96

 Additional moisture information for Alberta is available from Alberta Environment at: http://www.industrymailout.com/Industry/Redirect.aspx?u=113410&q=82918425&lm=11426940&r=106317&qz=1c50b90bcd4cb91ed4784de533593a3e

http://www.industrymailout.com/Industry/Redirect.aspx?u=113411&q=82918425&lm=11426940&r=106317&qz=4204520e2baa2c64fa5e9dc5b633eb2a

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Some areas still seeing lots of lygus

Growers in parts of eastern Manitoba, southern Alberta near Taber, Olds,  Didsbury, and Strathmore, and the Peace region near Spirit River are either contemplating spraying or are spraying for lygus bugs. Counts are as high as 50 per 10 sweeps in some fields. However, in many cases a large proportion of the population is still young nymphs that will do very little damage until they mature to later instars or adults, so consider crop stage when deciding whether or not to spray. Later maturing fields may still be at significant risk but fields that are nearing maturity may reach the swathing stage before these younger lygus bugs can do economical damage. Fields nearing maturity will also be less vulnerable as the pod texture becomes rubbery and tougher for lygus bugs to pierce. It is critical to remember that the preharvest interval for all insecticides registered for control is at least 7 days.  The pre-harvest interval is the time between application and cutting of the crop.

Adult lygus bugs are pale green to reddish brown/black, with a "V" mark one third of the way down their backs.  Young nymphs are pale green and resemble aphids, but with five small black dots on their backs and no cornicles.  Lygus cause damage by feeding on leaves, stems, flowers and pods, resulting in flower blasting and shrivelled seeds. The revised economic thresholds (using current crop and treatment costs) are about 4-15 lygus per 10 sweeps (or 0.4-1.5 per sweep) depending on crop stage, crop price and the cost of control. For each grower this threshold will be different. To effectively evaluate your lygus bug threshold, go to: http://www.industrymailout.com/Industry/Redirect.aspx?u=115753&q=82918425&lm=11426940&r=106317&qz=93dff749621ffefabdbe3def7dcda1ff

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Diamondback moth larvae still observed

Diamondback moth larvae are still showing up in parts of eastern Manitoba, in southern and west central Saskatchewan and in east central Alberta. Be on the lookout for diamondback during the podding stage. Given higher crop values this year, using numbers of around 20 per square foot, is likely appropriate. This threshold number may be slightly lower if early leaf drop forces  larvae to feed primarily on pods or if hot and dry conditions increase both insect activity and stress on the crop. For more information on diamondback moths refer to the following link: http://www.industrymailout.com/Industry/Redirect.aspx?u=114557&q=82918425&lm=11426940&r=106317&qz=88eb139d2dddcaeef36ba318bceb33ae

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Grasshopper questions

High grasshopper populations in southwestern Manitoba and northwestern and southeastern Saskatchewan are resulting in some questions about thresholds in canola. Canola is not a preferred food source for grasshoppers but they will cause damage to the crop in some instances. Often there will be an edge effect as grasshoppers move into canola from other preferred host crops, however it is important to scout throughout the field to determine the extent of the infestation. The recommended threshold for control in canola is about 7 to 12 per square metre but it is important to confirm that the species present are pest species. For more information regarding grasshoppers check the following link:

http://www.industrymailout.com/Industry/Redirect.aspx?u=124026&q=82918425&lm=11426940&r=106317&qz=107044c74d2ce99b527d832e47ca6383

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Bertha larvae emerging

Bertha armyworm moth trapping is now winding down as trap counts at many locations continue to decline. At this time there are a number of locations in Saskatchewan, including areas north of Tisdale, northeast of Saskatoon and several spots north and east of Regina, where the moth numbers are of concern. Young larvae are starting to emerge in some of these areas, so it is time to start scouting fields more intensively. When determining the number per square metre, make the assessment in various parts of the field and be sure to beat the plants together to dislodge all the larvae. Then thoroughly inspect the soil surface, including areas beneath leaf litter, to get an accurate count. Check the revised insect threshold link below for more information on appropriate economic thresholds.. For further information, go to the bertha armyworm section at the following link: http://www.industrymailout.com/Industry/Redirect.aspx?u=124027&q=82918425&lm=11426940&r=106317&qz=5de34ec0a27bc89caf6b2b60c28759bb

Prairie-wide bertha armyworm moth maps are in development, and web links for the Manitoba, Saskatchewan and Alberta are: 

MAFRI:

http://www.industrymailout.com/Industry/Redirect.aspx?u=121112&q=82918425&lm=11426940&r=106317&qz=a912fbba6d51102325909a4669c24687

SAFRR:

http://www.industrymailout.com/Industry/Redirect.aspx?u=122474&q=82918425&lm=11426940&r=106317&qz=9bc8ec5e8895846272be07cec91b7eaa

AAFRD:

http://www.industrymailout.com/Industry/Redirect.aspx?u=121114&q=82918425&lm=11426940&r=106317&qz=3ba1929762da67e8eedf86976ec69452

Moth numbers in the above maps are cumulative, which means the total moth count to date is reported. Trap counts are still being collected and added to the maps so keep checking for updates even in areas showing low risk because these numbers may still increase to a level of higher risk.

Remember these maps are an indication of risk in a region. Field scouting is still required to ensure economic damage does not occur in individual fields.

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Revised insect thresholds

Due to higher commodity prices, a committee of provincial entomologists has revised economic thresholds for several insects. A link outlining those revisions is available at: http://www.industrymailout.com/Industry/Redirect.aspx?u=124028&q=82918425&lm=11426940&r=106317&qz=fcf2323fd5eedd9b8b8248b74e55dd40

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Start watching for late season diseases

In addition to the blackleg symptoms noted in previous Canola Watch reports, some other late season diseases are starting to show up. Premature ripening resulting from these diseases may make plants much more susceptible to pod shatter, so knowing how prevalent they are will be important for making harvest management decisions. There have been a few reports of alternaria black spot in Manitoba, with fairly significant development of the small black spots on pods and stems in some cases. As well, some sclerotinia symptoms of premature ripening and bleaching of infected plants have been reported in parts of Manitoba and the Peace region. It will also be important to check the roots of crops as clubroot has begun to show up in some of the counties around Edmonton where it has been prevalent the last couple of years. Damage to roots from fairly widespread root maggot feeding also has the potential to provide a point of entry for root rots as well. For more information on these various diseases check the appropriate section of the Canola Growers’ Manual at the following link: http://www.industrymailout.com/Industry/Redirect.aspx?u=124029&q=82918425&lm=11426940&r=106317&qz=5c562b787f5d1e83f4c07231408f15ba

For pictures of symptoms of blackleg (and other canola diseases) check out our image library: http://www.industrymailout.com/Industry/Redirect.aspx?u=124030&q=82918425&lm=11426940&r=106317&qz=9da9457353724963d66cd1dfa66bd051

For growers and crop scouts in areas affected by clubroot you may be interested in the Clubroot Management Tour taking place next week, so check the following link: http://www.industrymailout.com/Industry/Redirect.aspx?u=124031&q=82918425&lm=11426940&r=106317&qz=a6c983b2487c31b927e8fe11d1deb010

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Deciding when to swath could be challenging

With crops nearing maturity, it is becoming clear that the early season stresses in many areas have contributed to a lot of variability in plant maturity within fields. While this may make it difficult to stick to the traditional swathing stage recommendations, growers still need to ensure that seed colour change is occurring when assessing the proper time to swath. The colour of plants and pods will vary among varieties as they mature. Do not use plant colour to gauge proper timing as some pods will appear ripe on the outside before the seeds are mature. Open up pods on the main stem and look at the colour of the seeds to accurately assess swathing timing.

Research indicates that the optimum stage to swath for both yield and quality is up to an average of 60% seed colour change (SCC) within the field. Unfortunately this year in some fields an average of 60% SCC may mean that a large proportion of the plants are at 80+% SCC and very prone to shattering. However, swathing much earlier may mean many plants are swathed prematurely increasing the potential for green seed issues and yield loss from shrinkage of immature seed. In these situations the best approach is likely to swath when the most mature plants are at about 60% SCC, provided that the least mature plants are showing some seed colour change at the base of the main stem and that the seeds in the upper pods (and branches) are dark green and firm inside. That will minimize yield loss from seed shrinkage, and improve the odds that the seed will cure although it will likely take longer and may require some moister conditions.

If the range in maturity is wider than this then growers will need to determine which plants represent the majority of the yield, to determine whether it is better to delay swathing and sacrifice a bit of yield to shattering or swath a little early and sacrifice some of the translucent seed in the least mature plants. Either way, avoid swathing during the hottest part of the day to minimize shattering of mature plants and slow dry down of less mature ones. This reduces the chance of green seed. This strategy will also help in situations where hail or insect damage is present or diseases such as alternaria black spot have predisposed the plants to shattering. If damage from these factors is fairly severe and shattering risk is high, growers may need to consider swathing earlier in these situations as well, but should try to wait for at least 20 to 25% average seed colour change if possible. To learn more about proper harvest field assessment, refer to the revised Canola Council publication "Canola Time of Swathing Guide" or the following link: http://www.industrymailout.com/Industry/Redirect.aspx?u=124032&q=82918425&lm=11426940&r=106317&qz=7b5427adf208597cd83062a2f48b0389

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Thinking about straight cutting?

There are a number of growers considering straight cutting their canola this year. To improve the odds of success, 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, drought and insect damage (e.g. exit holes from cabbage seedpod weevil, pod feeding by diamondback moth or bertha armyworm larvae).
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 Risk – canola seed in the pods is at significant risk for fall frost damage until the seed moisture drops below 20%. This will take much longer in a standing crop than in the swath, making late maturing standing crops much more vulnerable to yield loss and downgrading from frost damage. Late maturing crops are therefore not good candidates for straight combining.

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Considering chemical applications to assist crop dry-down?

Growers who have decided to straight combine some of their canola may also be considering pre-harvest weed control or desiccation, particularly in fields with uneven maturity. It is important to recognize that these products do not hasten the maturity of the less mature canola plants; they simply kill those plants off. It is also important to understand that these products are not designed to seal the pods against pod shattering, and may in some cases make the crop more vulnerable to shattering if harvesting is delayed. Be prepared to harvest as soon as the crop is ready, as the more rapid dry down will leave the crop vulnerable to shattering much sooner than if it is left to mature on its own. If applying any pre-harvest chemicals prior to harvest with ground rig sprayers, the use of crop dividers can reduce the amount of crop loss due to trampling and shattering. In addition, traveling back and forth in the direction of prevailing crop lean will further reduce losses.

If a Roundup Ready canola variety has been grown, a pre-harvest glyphosate application will assist in some dry down of green weeds and offer perennial weed control, but it will not dry down the crop. For other types of canola, it will be even more critical not to apply the product too early. Apply when the crop has 30% or less seed moisture content. At this stage, which is past the typical swathing timing, the pods are green to yellow and most seeds have turned from green to yellow or brown. For a faster acting desiccant like Reglone, it is even more important to delay application to allow seeds to reach physiological maturity. The recommended stage is when an average of 60 to 75% of seed (on the whole plant) has turned brown. Keep in mind that this will be well past 75% seed colour change on the main stem.

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Watch pre-harvest intervals and keep bins insecticide free

Before considering any further applications of fungicides or insecticides, remember to allow for the required pre-harvest interval for any products being considered. Growers need to ensure that the appropriate pre-harvest interval is followed to eliminate chances of excess residues appearing in the harvested seed, and damaging markets. Refer to the following links for information on pre-harvest intervals for some common pesticides and description of the importance of following pre-harvest intervals: http://www.industrymailout.com/Industry/Redirect.aspx?u=124033&q=82918425&lm=11426940&r=106317&qz=8ed2d781131e77e9c9efe3e0502be249

As growers prepare bins for storage of the upcoming harvest, it is important to note that oilseed crops like canola can absorb malathion from bin surfaces, and the resulting residues have been found in crop delivered to elevators. 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.industrymailout.com/Industry/Redirect.aspx?u=124034&q=82918425&lm=11426940&r=106317&qz=df65825745775c852b0810300183d002

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It’s not too early to think about weed control for next year

With swathing and harvest of other crops approaching, consider a valuable weed control tool to set up for next year's canola crop -- pre-harvest glyphosate. The challenging conditions this spring have resulted in less than ideal control of perennial and winter annual weeds in some fields so fall may be an opportune time to control them for next year. It's the most consistent and effective timing for many perennial weeds, providing an effective and economical alternative to in-crop applications. In early fall, perennial weeds are moving nutrients down into roots and rhizomes to prepare for winter. This is when they are most vulnerable to herbicide translocation to the roots and better control is possible. Wait three full days (72 hours) after application before cutting to allow thorough translocation of the herbicide to ensure extended long-term weed control. Keep in mind that generally the use of pre-harvest glyphosate on crops grown for seed should be avoided.

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Questions & Contacts

Direct questions regarding this report to Derwyn Hammond, Agronomy Specialist, Manitoba with the Canola Council of Canada at hammondd@canolacouncil.org, 204-729-9011.

Direct specific questions regarding regional issues to one of the following Canola Council of Canada regional agronomists or provincial oilseed specialists:

Ingrid Kristjanson, Manitoba Agriculture, Food and Rural Initiatives, Ingrid.Kristjanson@gov.mb.ca,
204-746-7504
David Vanthuyne, Agronomy Specialist, Eastern Saskatchewan, vanthuyned@canolacouncil.org,  
306-946-3588
Venkata Vakulabharanam, Saskatchewan Agriculture, Venkata.Vakulabharanam@gov.sk.ca  
306-787-2594
John Mayko, Senior Agronomy Specialist, Parkland West (West Central AB), maykoj@canolacouncil.org ph/fax: 780-764-2593

Doug Moisey, Agronomy Specialist, Parkland East (East Central AB & NW SK), moiseyd@canolacouncil.org, 780-645-3624
Matthew Stanford, Agronomy Specialist, Chinook (Southern AB & SW SK), stanfordm@canolacouncil.org,
403-327-4832
Erin Brock, Agronomy Specialist, Peace Region, brocke@canolacouncil.org,
780-568-3326
Murray Hartman, Alberta Agriculture and 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 and Rural Initiatives; Manitoba Canola Growers Association; United Farmers of Alberta; Viterra; Saskatchewan Ministry of Agriculture; Saskatchewan Canola Growers Association; Saskatchewan Canola Development Commission; Alberta Agriculture and Rural Development; Alberta Canola Producers Commission; BC Ministry of Agriculture and Lands; Agriculture and Agri-Food Canada, and the Canola Council of Canada