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Story Posted: May 11, 2011 Canola Watch: Spray now, Hold off on broadcasting Issues of the week: It will be a busy week of seeding in Alberta and western Saskatchewan as long as the weather holds. Soils are warm and seeds are germinating quickly. Rain delays continue in eastern Saskatchewan and Manitoba, but growers are reminded that canola seeded this week or next week will still have high yield potential. Many growers are enquiring about broadcast seeding, which can work but risks are high in no-till situations. Early reports of cutworms in the Vegreville area of Alberta are an important reminder that growers in central Alberta - and elsewhere - need to monitor fields closely and be prepared for early control. Watch the Friday webinar for tips. Crop and weather update Alberta: Seeding is underway and the province looks set for a busy week in the fields. Alberta crop report. Saskatchewan: Western Saskatchewan should see a lot of land seeded this week. Eastern Saskatchewan continues wet and is well behind the western region. Saskatchewan crop report. Manitoba: Rains this week add to already very wet conditions. Many growers have not seeded anything, and general seeding is not likely to start for another 10 days or more. Manitoba crop report. Try the drill before broadcast seeding Before jumping to the broadcast option, try the drill first to assess the seed placement situation. It may work, but consider the following:
If growers decide on broadcast seeding, know the risks. Agronomics and economics must both be part of the decision. Click here for broadcast seeding tips and risks. Consider split fertilizer when soggy seeding John Heard, fertility specialist with Manitoba Agriculture Food and Rural Initiatives, prepared an article called "Options for applying nitrogen fertilizer in a wet, late spring." The article says top-dressing nitrogen allows for uncomplicated, quick seeding. Growers don't have to put as much fertilizer in the drill tank, which extends the time between fills. Nitrogen options for post planting application are urea, blends of urea and ammonium sulphate (to try to reduce volatile loss potential with straight urea), dribble band UAN, urea treated with Agrotain, and UAN treated with Agrotain. Ammonium sulphate (15-0-0-21) also provides a sulphur top up, which could be valuable if growers did not apply all the sulphur they needed at seeding. Urea's average performance is still acceptable for top dressing, Heard says, especially with good soil contact and favorable moisture. If rain is not in the forecast, Agrotain will limit losses until rains come. Band stripping of dry urea will minimize surface contact and may reduce volatilization potential. Performance of broadcast UAN solution may not be as high as for other forms of nitrogen, but Heard says spoke-wheel injection or dribble application will improve UAN performance. ESN is not recommended for post seeding applications. How much to apply? Growers may need to top dress up to 30 pounds per acre of actual nitrogen to see a noticeable difference with the naked eye. Adding liquid nitrogen to the tank when herbicide spraying provides less than 10 pounds per acre, which will likely not be sufficient if early applications were conservative and the crop is truly deficient. When trying this, consider a test strip to see if it has any effect on final yield. Nitrogen rate calculators. As growers head to the field, they have a chance to make some last minute adjustments to their nitrogen rates. Here are links to two calculators that can help with the decision: MAFRI Alberta Agriculture Spray weeds now, even if seeding is delayed Even if growers don't expect to seed for 10 days or more, they may want to consider a pre-seed burnoff now (as long as fields can support a sprayer) to get weeds at smaller stages. For more information on CleanStart and pre-seed glyphosate, click a province for a link to its guide to crop protection: Alberta Saskatchewan Manitoba. Growers who have already seeded and intend to apply a post-seeding/pre-emergence burnoff will want to act fast. The window of opportunity could be narrow this year. In Alberta and Western Saskatchewan, warm moist soils are encouraging rapid crop emergence. Click here for an ACPC radio program on early season weed control tips. Consider herbicide residue before switching canola fields Wet soil conditions can create unexpected herbicide carryover. With the lack of oxygen in saturated soils, herbicides that rely on aerobic (oxygen loving) bacteria for breakdown may not have broken down as effectively as expected. In some severe cases, breakdown may be as limited as under drought conditions. Check with the manufacturer of residual herbicides used in past seasons and ask whether they are comfortable with canola as a follow crop when field conditions have been saturated. Tips to help canola mature faster Next, look at days to maturity for the variety, adjusting for regional differences, and work back from the frost date. For example, if the mean date for first fall frost in northeast Saskatchewan is the week of August 31 to September 6, then a variety with 100 days to maturity should be seeded by May 20 to be at lower risk of fall frost damage. If growers decide that measures to hasten maturity are warranted, here are steps to consider: Switch to an earlier-maturing variety. Switching from a long-season to an early-season napus variety can gain a week. Switching to a rapa variety can gain two weeks, but rapa has lower yield potential to start with and doesn't offer the weed control options. Also note that seed exchange opportunities may be limited give the high demand for canola seed. Seed shallow. Canola seeded half an inch deep can emergence 3 or 4 days earlier than canola seeded deeper. It may be necessary to slow down to achieve this consistency. Because of changing soil conditions and the potential for mechanical issues with drills, check the seeding depth periodically, particularly when moving field to field. Increase the seeding rate. A higher rate leads to a denser stand, less branching and hence earlier maturity. This can gain a day or two. Put phosphate with the seed. Pop-up phosphate fertilizer applied with the seed can gain a day or two, if levels of readily available P in the soil are inadequate. Reduce nitrogen rates, keeping in mind a realistic yield potential. Avoiding excessive nitrogen availability can reduce the duration of early vegetative growth leading to earlier maturity by a day or two. If weather turns around and June is hot and dry, canola can make up for lost days earlier in the season. Growers may consider a post-emergence fertilizer application - as long as they're comfortable there is still time in the season for the crop to mature. Thanks to Murray Hartman, oilseed specialist with Alberta Agriculture and Rural Development, for help with this article. Start insect scouting right after seeding
Fields emerged first could be at higher risk for flea beetle damage. If you are noticing flea beetle activity, make notes as a reminder to check those fields more often. When checking seeding depth also check around for cutworms. As for wireworms, growers need to scout fields before seeding canola if they suspect a wireworm problem. No insecticides are registered for wireworm control in canola. Wireworm seed treatments are available for cereals, so that might be a better option for fields infested with wireworms. Canola that gets off to a quick start and grows vigorously will be better able to tolerate wireworm feeding.
For more information, contact a Canola Council of Canada agronomy specialist in your region:
This media release is supported regionally by: Alberta Canola Producers Commission; SaskCanola; Manitoba Canola Growers Association; Canola Council of Canada; Peace River Agriculture Development Fund; B.C. Ministry of Agriculture & Lands.
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