Canola Watch

2006 Canola Watch Reports

Canola Watch Report No. 5 Western Canada – May 25, 2006

In this issue: (click the bookmarked links below to move to specific sections of this report)Canola seeding close to complete

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 seeding progressed rapidly this past week across much of western Canada. Seeding is completed or close to wrapping up in many areas except for parts of northwestern Manitoba, northeastern and east-central Saskatchewan and the eastern part of north-central Alberta with about 25-75% completed. Wet conditions and regular precipitation continue to limit rapid seeding progress in these areas.

Soil moisture conditions continue to range from poor to excessive across western Canada. Precipitation this past week ranged from a trace up to over 50 mm. Areas of east-central and northern Saskatchewan and northwestern and southeastern Manitoba remain wet. Small pockets of dryness continue to remain in parts of southwestern Saskatchewan and parts of central Alberta near Red Deer continue to experience dry topsoil moisture. Most of the Peace Region received more rain (10-25 mm) this past week which will assist in germination and early crop development but most of the subsoil remains dry.

For current maps of moisture conditions from PFRA for western Canada, check the following links for precipitation since September 1 and May 22:
http://www.agr.gc.ca/pfra/drought/prpay06_e.htm
http://www.agr.gc.ca/pfra/drought/prpgs06_e.htm

The latest crop report from Manitoba Agriculture, Food and Rural Initiatives is available at:
http://web2.gov.mb.ca/agriculture/mwcr/

The latest crop report from Saskatchewan Agriculture, Food & Rural Revitalization is available at:
http://www.agr.gov.sk.ca/docs/reports/crop_report/crprpt060521.pdf

Additional moisture information for Alberta is available from Alberta Environment at:
http://www3.gov.ab.ca/env/water/WS/data/precipmaps/weekly.pdf

Prolific weed growth continues due to favorable soil moisture conditions and warm soils in most of the prairies. Many areas report more pre-emergence glyphosate applications this year than in the past. In-crop spraying of early seeded crops started in earnest this past week, with wild oats, volunteer cereals and other grassy weeds especially noted.

For more information on current product recommendations, check the following links from the provincial governments for their respective Crop Protection Guides:
http://www.gov.mb.ca/agriculture/crops/cropproduction/gaa01d01.html
http://www.agr.gov.sk.ca/DOCS/crops/cropguide00.asp
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex32?opendocument

Growers should consider the use of check strips to assess herbicide performance and weed pressure. Refer to the following Canola Council press release for further information on establishing check strips:
http://www.canola-council.org/about-us/media-news/media-releases/media-may1606.html

For further weed control and spraying tips, refer to the May 17/06 Canola Watch report at: http://www.canola-council.org/seed/canola-watch/watch06-may17.html

More frost was reported this past week in parts of Manitoba, eastern Saskatchewan and the Peace region near Fairview. Although damage was light in most instances, some reports of considerable crop blackening and subsequent re-seeding were noted in southeastern Manitoba. The amount of frost injury will depend on moisture conditions, rate at which thawing occurs, the growth stage of the plant, and the amount of cold temperature hardening the plant has experienced.

Canola seedlings will usually recover from a light spring frost that does not damage the plant’s growing point. A light frost that wilts the leaves, but does not cause any browning, will not severely damage the plants. Some discoloration of the leaves may occur, usually a yellowing or whitening especially under drought conditions.

Remember that a proper assessment of frost damage cannot be made for several days--until it can be determined whether new growth is appearing from damaged plants.

For further information on assessing spring frost damage, refer to the May 17/06 Canola Watch report.

Growers who still have canola left to seed should be reassessing the maturity suitability of their chosen varieties. The accumulation of temperature or Growing Degree Days (GDDs) has a major influence on days to maturity for canola. In the short and mid season zones of western Canada, maturity for B. napus varieties will range from 95 to 125 days, depending on the growing season heat accumulation. B. rapa varieties usually range from 80 to 115 days to maturity.

First, find out how many days to maturity are required for the variety that is to be seeded. Usually the variety will be rated as; number of days earlier (minus) or later (plus) or equal to the check. Using a typical first fall frost date, count back the days to maturity to get to the safe seeding date. For example, if the first frost is August 25 on average and maturity of the check in the area is 103 days, counting back gives a safe seeding date of May 17. If the variety to be seeded is five days earlier in maturity than the check, this means that in a typical year, seeding up to May 22 would be acceptable for that variety. If the variety does not meet the requirements, ask your local retailer to suggest other suitable varieties.

Manitoba growers can check the following link to determine their frost-free days:
http://www.gov.mb.ca/agriculture/climate/waa50s00.html

Alberta growers can check the following link to determine their frost-free days:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex10

Remember to begin scouting fields by 7 to 10 days after seeding to detect germination problems early. With ample moisture and warm soils emergence can begin to take place within a week. Refer to the following Canol@Fact for more information: http://www.canola-council.org/PDF/seed_to_21days.pdf#zoom=100

Flea beetles continue to be reported in central and northwestern Manitoba, in southeastern, south-central and western parts of Saskatchewan, in central Alberta near Wetaskiwin and in the Peace region. Many of the reports continue to be noted on volunteer canola and wild mustard, or on fields with tight canola rotations or where no insecticide seed treatment was used.

Following are tips for monitoring and assessing flea beetle damage of emerging crops. Scout fields daily in the spring, especially in areas with high flea beetle pressure last year, and assess damage to cotyledons and the first true leaves of seedlings. Continue scouting for the first 14 days after emergence, especially on sunny, calm days when temperatures exceed 14°C; scouting twice a day may be warranted when weather conditions are ideal for flea beetle feeding. Determine the extent and distribution of damage by collecting plants at random while walking across the field, as well as checking all field and slough margins where the insects over-winter. Estimate the foliage damage, utilizing the following visual aid in assessing leaf area damage more accurately. Flea beetles generally invade canola fields from the field edges. Damage and flea beetle numbers may be higher at the field edge than farther into the field.

Canola seedlings can withstand 50% leaf loss. However, flea beetles can locate attack and quickly injure or destroy seedlings shortly after emergence. Therefore, the action threshold for flea beetle feeding on canola is when there is 25% defoliation and flea beetles are present. Make sure to check the entire plant for signs of flea beetle feeding, the stem may also have signs of damage. Applying controls at 25% defoliation will reduce the risk of flea beetle damage reaching a level where yield loss and plant development are substantially reduced. If damage only exceeds threshold levels near the field edges, a foliar spray around the field edges may provide sufficient protection. However, on hot and calm days flea beetles are capable of moving farther distances and may cause significant damage further into the field.

When assessing economic thresholds, also consider growing conditions. When flea beetle feeding is combined with poor plant growth during hot, dry weather, canola can tolerate less feeding than if plants are growing rapidly under more ideal growing conditions.

It has been noted that in some cases this spring, spraying for flea beetles has been occurring before threshold levels have been reached. There are examples of this occurring on farm saved seed where producers did not have access to insecticide seed treatments. Another situation where insecticide application has been seen is where product “bundling” has made insecticide tank mixing with first in crop herbicide application very inexpensive. If crop staging and environmental conditions are favourable for flea beetle, and the window of protection from the seed treatment you have chosen has almost run out, only then should a foliar insecticide be considered.

Beneficial insect populations are very sensitive to insecticides, and unwarranted insect spraying may cause damage to beneficial populations. Diadegma insulare is believed to be the main predator of diamondback moth larvae, and is believed to be the cause of the diamondback population crash last year. Spraying needlessly in the spring may allow harmful insects to get a head start on beneficials, making a later season insecticide application necessary where it may not have been before.

Cutworms have been noticed near Craik, SK, where one large field was recently reseeded due to damage. Be especially vigilant in areas that had cutworm damage last year. Scout canola fields from early-May to mid-June to determine whether bare areas with no seedlings have resulted from cutworm damage. Check the edges of bare areas for cut-off plants. Wilted, dead or cut-off plants (weed or crop seedlings) will be seen. Dig around the roots of these plants for cutworms. To collect cutworm larvae, a garden trowel and a soil sifter are useful tools. Cutworms may be found in dry surface soil down to about 5 cm (2") below the soil surface. The small, worm-like larvae curl up or attempt to hide in the debris. Pale western cutworm larvae are greenish or slate-grey with a brown head, while mature red-backed cutworm larvae are dark grey with two broad, dull, brick red stripes along the back. Cutworm control may only be necessary in small areas of the field, when bare patches appear and large numbers of the insect are still actively feeding. Be sure to note the size of the larvae you see in the field. Large specimens (over 25 mm long) will soon stop feeding and pupate and are also more difficult to kill. If cutworms are still small, and numerous enough to warrant control, apply one of the registered insecticides. Apply surface treatments in the evening, preferably under warm, moist conditions, as cutworms are active at night and these treatments will only control surface-feeding larvae. Do not disturb the soil for five days after treatment.

Also refer to the new Canol@Fact on cutworms:
http://www.canola-council.org/PDF/May4_2FS_Controlling_Cutworms.pdf#zoom=100

Wireworms continue to be observed in northwestern Manitoba and in central Saskatchewan. It is important to scout fields where wireworms have been seen or suspected in the past, as they can potentially spend 4 or more years of their life cycle as larvae in the soil. Wireworms prefer cool, moist soil and tend to be actively mobile in the top six inches of the soil. Early in the growing season, they are attracted to the carbon dioxide produced in the germination process and will come to the surface to feed on emerging plants. This is the time when they will cause the most damage to crops, usually by shredding below ground plant tissue. Whole potatoes buried in marked locations in a field in the spring or from early to mid August will indicate whether wireworms are present. Bury the potatoes 10 to 15 cm deep then dig them up after a couple of weeks, and examine them for wireworm tunnels. Monitor your fields each year. Another suggested method for using grain bait stations for monitoring of wireworm is outlined in the following web link from OMAFRA:
http://www.omafra.gov.on.ca/english/crops/pub811/6wire.htm#technique

To sample for larvae, sieve the soil through a screen. Mark out areas 50 cm x 50 cm and sieve the soil to a depth of 15 cm (6 inches). Repeat in different areas of the field to determine an average number of larvae per square metre. If wireworms are found to have significant populations on a particular field, canola should not be planted there as there are no chemical controls for wireworms in canola.

Due to the warm and dry weather in many regions, early hatches of grasshoppers have been noted in isolated areas, some up to the 3rd or 4th in-star stage already. Any grasshoppers emerging at this time of the year are unlikely to be pest species. For more background information on grasshoppers, including identifying pest and non-pest species, refer to the following website from Dan Johnson at the University of Lethbridge:
http://people.uleth.ca/~dan.johnson/htm/dj_gh_guide.htm

For the latest grasshopper forecast map for 2006, refer to the following link:
http://www.canola-council.org/PDF/map_grasshoppers_2005.pdf

Direct 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 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

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, Agronomist, Central Alberta,
moiseyd@canola-council.org, 780-645-3624

Jackie Heck, Agronomist, Peace River Region,
heckj@canola-council.org, 780-853-5261

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@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; 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.

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