Seeding isn’t late. Take it slow

After a week or more of idling due to cool and wet conditions, growers want to get rolling. We remind them that it still pays to slow down to improve placement. Do everything right to take advantage of prime timing and soil moisture conditions. That means seed shallow, check that each drill run is on the same plane, and slow down. With an average maturity of 100 days, canola seeded this week will mature mid to late August. This isn’t late.

For more on this topic, listen online to ACPC’s radio reports. And if you missed it last week, go to ACPC's YouTube site and watch CCC agronomist Doug Moisey explain why slowing down can help.

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Calibrate the drill between seed lots

Canola thousand seed weight (TSW) can range from less than 3 grams up to 6 grams or more. This can have a dramatic effect on seeding rate. Click here to see a CCC video on the topic. To calculate an appropriate pound per acre seeding rate for each seed lot, use this formula:

Seeding rate (lb./ac.) = [9.6 x desired plant density (plants/ft2) x TSW (grams)] ÷ estimated seed survival (%, expressed as a whole #).

For example, if TSW is 4 grams, desired plant population is 10 plants per square foot and estimated seed survival is 50%, then the formula goes like this: (9.6 x 10 x 4) ÷ 50 = 7.7 pounds per acre.

Once the appropriate seeding rate has been determined, check that seeding equipment is properly calibrated to deliver the desired pounds of seed per acre. Consult the operator’s manual for recommended calibration instructions, or follow the following procedure:
1. Measure out 100 feet.
2. Collect the seed from several drill runs over this
distance. Weigh the collected seed.
3. Calculate the seeding rate using this formula: Grams of seed ÷ number of drill runs collected ÷ row spacing (inches) x 12 = seeding rate (lb./ac.)
For example, if the grower collects 18.75 g from 5 drill runs and row spacing is 9”, then the actual seeding rate is 18.75 ÷ 5 ÷ 9 x 12 = 5.0 lb./ac.

Adjust the seeder and recalibrate until the target seeding rate is achieved. Then record the drill settings, TSW and seeding rate. For more detail, click here to download the factsheet Plant Populations for Profitability and click here for tables that give a seeding rate based on TSW, target plant stand and estimated seed survival.

On that note, with the size of hybrid seed today — 5 to 6 grams per 1,000 seeds is typical — growers are looking at 7 pounds or more per acre to hit the target minimum stand of 7 plants per square foot. That’s based on a survival rate of 50%. Since most growers plant 5 pounds per acre, or less, they need a survival rate of 70% or 80% to hit the target plant stand. That may be possible this year, given the moisture conditions, but only if they do everything else right. See article 1.

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Hit those cleavers early

Cleavers have emerged and are growing rapidly in scattered fields across the Prairies. Derwyn Hammond, CCC agronomist for Manitoba, says some are three inches tall already. “If growers wait until in crop to control those large cleavers, they’ll have trouble,” he says.

Know the weed spectrum for each field before seeding. If cleavers and other weeds are large or the weed spectrum includes species that aren’t controlled effectively with approved rates of the in-crop product a grower plans to use, a pre-seed burn to control these weeds can preserve the canola yield and profit potential in that field.

As we emphasized in last week’s Canola Watch, early weed control in general contributes to higher canola yields. Pre-seed burnoff controls weeds when they’re smaller and easier to manage and reduces the competition for young canola plants.

For some products, growers can seed the same day they spray or the day after. For larger weeds, growers may want to give the herbicide an extra day or two to translocate to the growing points. Check provincial guides to crop protection products for rates for larger weeds and recommended seeding delays. For your guide, click your province: Alberta Saskatchewan Manitoba

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Rotate herbicide systems in tight rotations

Some growers are looking at tighter rotations for this year, seeding canola on fields that were in canola two years ago or, in some cases, last year. This is not a best practice for well-known reasons of disease build up and lower yields. In Manitoba, for example, canola on canola stubble yields 83% of the average canola yield for the province, according to Manitoba crop insurance data. Canola on canola also raises the issue of volunteer canola control. Growers who choose to seed canola on canola should rotate herbicide-tolerance systems on that field. For example, if they seeded Roundup Ready canola two years ago, this year use a different system on that field. This provides an important opportunity for post-emergent volunteer control, especially if growers missed an opportunity to apply CleanStart (the only pre-seed burnoff registered to control Roundup Ready volunteers) before seeding.

Volunteer Roundup Ready canola is not a benefit in a Roundup Ready crop. Volunteers are often in clusters, particularly in strips where the windrows were the fall before. That means elevated plant counts in those strips, which lead to lodging and sclerotinia infestation. Volunteers are also usually at different stages than the crop, which makes it difficult to time disease control and harvest. And volunteer seed is untreated, so it can contribute to the build up of seed and seedling diseases in the soil. Volunteers, as second generation seed from original hybrids, also yield less than the original hybrids. F2 seed (second generation) averaged 13 per cent less yield than F1, according to Agriculture and Agri-Food Canada research. Finally, we know that herbicide-resistant weeds have evolved, and it usually happens in fields where the same herbicide groups are used year after year.

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Limit nitrogen in the seed row

Many growers strive to apply all their fertilizer during the seeding pass. This one-pass system is a good way to save fuel, minimize soil disturbance and maintain the integrity of the seed bed, but it does present challenges for seed and fertilizer separation. Putting all seed and fertilizer down a single-shoot opener presents a high risk of seedling injury and a greatly reduced canola stand.

Growers need to keep nitrogen out of the seed row, for the most part. When applying 100 pounds of actual nitrogen per acre, for example, most or all of it should go in a side band, paired row or mid-row band away from seed and young emerged seedlings. Canola at its earliest stages needs very little nitrogen. When it needs nitrogen in larger amounts, it has the roots in place to go get it. Too much nitrogen at early stages can burn seed and seedlings, causing them to lose vigour and perhaps die. Nitrogen toxicity can also hinder early roots from accessing phosphorus — a nutrient the crop needs for early growth.

So how much seed placed nitrogen is too much? As this table (see below) from a Saskatchewan Ministry of Agriculture factsheet shows, tolerances for nitrogen in the canola seed row range from zero to 40 pounds per acre, depending on row width, row spacing, and soil conditions. For example, using a one-inch knife on 9-inch spacing and seeding in medium textured soil, seed-placed urea should not exceed 10 pounds of actual nitrogen (22 pounds of urea) per acre. Urease inhibitors and coated time-release prills make it safer to apply higher rates in the seed row, but even then growers still have a large amount of N to apply in a side band, paired row or mid-row band.

Click here for Manitoba seed-placed nutrient recommendations, which tend to be more conservative due to more calcareous soils.

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Suspected cutworm actually a cranefly larva

Here’s another example why proper pest identification is important. The “suspected” redbacked cutworms found in the Carrot River area last week turned out to be cranefly larvae, commonly called “leatherjackets.” They were the same size as cutworms but were at a more advanced stage than redbacked cutworms would be at this time of year. They didn’t curl into a ball the way cutworms do. See the photos below. The second photo shows the cranefly larvae beside a wireworm.

Cranefly and cranefly larvae are not known to cause economic damage in canola, so insecticide control is not warranted. Craneflies overwinter as larvae in the soil quite close to the soil surface. They feed on decaying vegetation and crowns, underground stems, or roots of a variety of plants. Grasses are preferred, but they actually have a broad host range. Juliana Soroka, entomologist with AAFC in Saskatoon, has seen them damaging potatoes around Outlook, Sask.

Had they been cutworms, the grower may have prepared to spray. When dealing with any pest, identify it correctly before making a control decision.Growers in this region will be on the lookout for cutworm this year after a bad outbreak in some fields last year. For more on cutworm, including photos, click here. Alberta Agriculture and Rural Development is collecting cutworms to grow to adulthood and identify. Growers and agronomists who find cutworms and would like to identify them, contact Scott Meers entomologist with AARD.
  

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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
For information on activities in Saskatchewan, visit SaskCanola at www.saskcanola.com.

 

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