Story Posted: May 19, 2010

Canola Watch 4: A second pre-seed burn, glyphosate tips, scout for flea beetles

In This Issue: Not too late for pre-seed burnoff, Tips to get the most out of glyphosate, Tips to get the most out of CleanStart, When it's warm, flea beetles go everywhere, When is too late to seed canola?, Questions and contacts.

Issues of the week
May 19, 2010 - After a week of full-out seeding, canola seeded early last week is already emerging. Weed control is critical, especially if growers didn't do a pre-seed burnoff. Weeds, including volunteer canola, have been emerging over the past month, in many cases, and some plants are large. Control only gets harder and the damage more costly to canola yield and profitability the longer those weeds are left unsprayed.

Crop and weather update
Peace (B.C. and Alberta): Seeding will wrap up shortly in most areas. The earliest seeded canola has emerged, but many fields are still just germinating and haven't poked through the surface. Dry conditions are a concern in the central and east areas especially.

Alberta: In the southern region, seeding progress is nearing half way, but ranges from 10% in the wettest areas southwest of Lethbridge to 65% on the north side of Highway 1.
In the central region, canola seeding ranges from just started in the Coronation area to 90% complete north of Edmonton. Soil moisture is generally good, but ranges from fair-adequate around Mayerthorpe-Barrhead to excessive in areas east of Trochu. Some early seeded canola has emerged. Read the Alberta crop report.

Saskatchewan: Progress ranges from 2% seeded in areas around Strasbourg, Melfort and Tisdale to 70% seeded in areas around Carrot River and Aylsham in the east and Kindersley in the west. With forecasts for a warm week, the majority of canola should be seeded this week if all goes well. Read the Saskatchewan crop report.

Manitoba: Seeding is only 10% complete in some northwest areas, but generally around 50% for the province. Across the south, 20% to 30% of canola is emerged. Weed pressure is high, especially on fields that did not get a pre-seed burn and on fields seeded before the rains - which have kept sprayers off the field. Read the Manitoba crop report.

Quick Hitters
Sulphate fertilizer supplies are just keeping up with the demand. If your supplier runs out of sulphate when you are seeding, don't panic. You can broadcast ammonium sulphate up to the four leaf stage as an alternative to delaying seeding.

In fields where volunteer cereals are emerged ahead of the broadleaf weeds and the crop, the crop may benefit from an early grass herbicide application. Apply your grass herbicides as soon as possible and with rates in line with the stage of weeds.

Growers with cleavers in field seeded to Liberty Link canola should evaluate the stage of the cleavers and, if applicable, consider a high rate of Liberty with their first pass.

With the good yields and heavy crops last year, many growers have had trouble seeding into with heavy trash. Residue management such as harrowing or tillage may be needed. Some growers may resort to burning, in which case they should check with their RM office about fire bans and burning permits.

When scouting fields with stand establishment problems, look for the blue seed coat at or near the root of the seedling. This will indicate whether the affected plants are from the current year's seed or whether the plants may be volunteers from previous years. Refer to the CanolaFact "Factors affecting canola survival for seeding to 21 days after emergence" for more information on assessing a stand.

Some seed lots are very dry, which puts seed at higher risk of cracking as it moves through the drill. (See the photos.) Put a tube sock over a few hoses above the opener to check for cracking. Slowing down ground speed will reduce volume per second, and should reduce cracking. For double shoot openers, adjust air damper for seed delivery.

Not too late for pre-seed burnoff
We have conditions for fast and effective herbicide results: sunny, warm and humid. Good performance also depends on evening temperatures remaining well above freezing.

If growers haven't seeded yet, they should consider pre-seed burnoff - even at this date. If they just seeded, consider a post-seed, pre-emergent spray. Large weeds left standing to compete with the emerging crop, which won't be up for 10 days if you seed today, will take a huge bite out of yields - and will be that much harder to control.

What about a second pre-seed burnoff? If growers did an early pre-seed burn two weeks ago but haven't seeded the crop, they may want to consider a second pre-seed application. "That application can be the equivalent of an in-crop spray if it happens late enough in the spring," says Clark Brenzil, weed management specialist with Saskatchewan Ministry of Agriculture. "Canola growers make three herbicide applications now with their double shots, so how does this differ from making two burn-offs and one in-crop app? The diesel to run the sprayer is the same but the cost of herbicide will definitely be less."

Work by Neil Harker et al at the AAFC Lacombe Research Centre also shows that a second in-crop glyphosate application rarely pays off in terms of higher returns from the crop. The second in-crop glyphosate application, according to study results, did reduce weed biomass, but canola yield was not significantly different.

Tips to get the most out of glyphosate
Retail agronomists are getting asked whether it's OK to go in earlier than 1-3 leaf stage of canola with Roundup. The answer is yes. The qualifier is if the crop - and the weeds - are under stress. In that case, hold off until conditions improve for better weed control and to avoid stalling the crop.

On that topic, here's how to get the most out of glyphosate:

• Weeds should be actively growing.
• Use water volumes of 5-10 gallons/acre.
• Smaller weeds are easier to control. Growers want to make every effort to control species such as buckwheat, winter annual weeds at the 1-3 leaf stage.
• Sunny, warm and humid are optimum performance for top performance. This includes warm temperatures well into the evening.
• Avoid spray speeds that will create dusty conditions. Tip from Clark Brenzil: If this can't be avoided, spray from downwind to upwind to minimize the dust deposition on unsprayed leaves.

Click here for a PDF of the table "Maximize glyphosate performance" (from the Alberta Reduced Tillage Linkages website.)

Tips to get the most out of CleanStart
Canola volunteers are a weed that should be controlled ahead of your canola crop. CleanStart is the only pre-seed burnoff registered for use ahead of canola that can control Roundup Ready volunteers. There has been lot of interest in using Clean Start as a pre-seed burnoff, most likely due to producers pushing rotations. CleanStart is a mix of glyphosate plus group-14 carfentrazone. Carfentrazone is a contact herbicide with photosynthetic inhibitor activity. It is non residual, which means cropping flexibility. Here are tips to get the most out of CleanStart:

• Coverage is critical. Use no less than 10 gallons/acre of water. Use higher water volumes when weeds are dense.
• Weed staging: Smaller is better. You can spray Roundup Ready canola volunteers at the 1-3 leaf stage.
• Spray when conditions are warm, sunny and humid.
• Do not use additives that alter spray water pH. The formulation contains its own compounds to bring spray water to the proper pH for optimum performance.
• Note: Weeds stressed by drought, hot or prolonged cool temperatures (less than 15°C) and poor fertility are more difficult to control as these conditions can affect the leaf surface and minimize movement of the herbicide into the plant.

When it's warm, flea beetles go everywhere
In warmer temperatures, flea beetles are more mobile - so the technique of scouting only at field edges no longer applies. It will be important to scout throughout fields for flea beetle hot spots.

Spray only when damage reaches the action threshold - which is 25% of leaf area eaten or damaged. (See the photo at the top.) With canola seeded last week and emerging this week, seed treatment should still be protecting the crop from flea beetles. But scout anyway. Canola seeded three weeks ago and just emerging now could be at higher risk because the seed treatment protection will be tapering off.

We also caution growers who tank-mix herbicide routinely with insecticide without first checking that flea beetle pressure is at the threshold can increase the risk of flea beetles developing resistance.

When scouting: Also watch for feeding on stems and undersides of leaves where damage is less obvious. (See the photos at the bottom.) "Stems are not the feeding site of choice, leaves are," says Julie Soroka, entomologist with AAFC in Saskatoon. She adds that stem feeding is more common in cool conditions. We saw serious damage from stem feeding about eight years ago, she says. "It's not common, but it can happen."

When is too late to seed canola?
Troy Prosofsky, CCC agronomy specialist in southern Alberta, is getting this question a lot. Southern Alberta often seeds canola about two weeks before everyone else on the Prairies, and by mid to late May growers are wondering whether to skip canola and plant barley instead. To answer the question whether it's too late, consider the profit potential of the option crop. All crop yield potential drops with late seeding. Also consider local trends for first fall frost. And finally, check for crop insurance cutoff dates.

For background, click here to watch an the interview with Ross McKenzie on realagriculture.com. Lethbridge studies show that canola yield drops 1.7% per day for every day seeding is delayed after May 1, says McKenzie, agronomy specialist with Alberta Agriculture and Rural Development. When conditions are right for seeding, "I'd probably seed canola first," he says. "And seed shallow. Just scratch it in."

Questions and contacts
If you have general questions about Canola Watch, direct them to Jay Whetter, whetterj@canolacouncil.org or 807-468-4006.

If you have questions on regional issues, contact one of the following Canola Council of Canada regional agronomists or provincial oilseed specialists:

• Derwyn Hammond, senior agronomy specialist, Manitoba, hammondd@canolacouncil.org, 204-729-9011
• Jim Bessel, senior agronomy specialist, Central Saskatchewan, besselj@canolacouncil.org, 306-373-6771
• Tiffany Martinka, agronomy specialist, Eastern Saskatchewan, martinkat@canolacouncil.org, 306-231-3663
• Clint Jurke, agronomy specialist, Western Saskatchewan, jurkec@canolacouncil.org, 306-821-2935
• Troy Prosofsky, agronomy specialist, Southern Alberta, prosofskyt@canolacouncil.org, 403-332-1412
• Doug Moisey, senior agronomy specialist, North East and East Central Alberta, moiseyd@canolacouncil.org, 780-645-9205
• John Mayko, senior agronomy specialist, West Central Alberta, maykoj@canolacouncil.org, 780-764-2593
• 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, B.C. Ministry of Agriculture and Lands, Kerry.Clark@gov.bc.ca, 250-784-2559
• Venkata Vakulabharanam, Saskatchewan Ministry of Agriculture, Venkata.Vakulabharanam@gov.sk.ca, (306)787-4668
• Ingrid Kristjanson, Manitoba Agriculture, Food and Rural Initiatives, ingrid.kristjanson@gov.mb.ca, 204-746-7504

This report is supported by each of the provincial canola grower associations. For more information on some of their activities, check out the following links:

• The Alberta Canola Producers Commission (ACPC) has a free e-newsletter called Alberta Canola Connections. Visit canola.ab.ca and click the sign-up icon on the right site of the homepage.
• In Manitoba, sign up for the Manitoba Canola Growers Association newsletter at Canola Growers E-update by visiting www.mcgacanola.org.

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