|
|
Story Posted: February 07, 2011 Canola Watch: New drill tips, Spoilage increase, Cleavers In This Issue: Take time now to prep new drill, Wider rows can increase damage from seed-placed N, Why canopy closure matters, More heated canola than usual, Snow cover benefits cleavers, Soil testing in winter, Coming events, Questions and contacts. Take time now to prep new drill For more pre-season drill prep, click here to read a Canola Council of Canada factsheet and click here for an article from the Alberta Reduced Tillage Linkages archive.
Use a urease inhibitor (Agrotain) or polymer coated nitrogen (ESN). These products slow the release of ammonia and ammonium from urea fertilizer, which increases seed safety and allows for higher rates of nitrogen to be placed with the seed. They work in different ways to achieve this result. ESN's polymer coating wraps urea prills in plastic that lets water in slowly, and then slowly releases ammonia and ammonium back out into the soil. This keeps the concentration of ammonia and ammonium lower early in the season when seedlings are most sensitive. The urease inhibitor in Agrotain slows the hydrolysis of urea into ammonia and ammonium, reducing concentrations early in the season. Agrotain, the company, says Agrotain allows for safe seed placement of nitrogen at rates up to 50% higher than provincial recommendations for seed-placed nitrogen. A study by Saskatchewan Soil Conservation Association in 2000 compared seed-placed nitrogen treatments, and found that Agrotain and polymer-coated urea reduced seedling mortality and improved crop yield when compared to untreated urea. "Polymer coating tended to be more effective for improving emergence, seed yield and N uptake than the Agrotain coating and the effect was significant in some cases," the study report says. A current nine-site Alberta study, led by Alberta Agriculture in Lethbridge, is looking at canola stand establishment and yield for seed-placed ESN compared to seed-placed untreated urea. The researchers have completed only three of the four years and the study results are not yet published, but so far it appears that ESN provides a significant improvement in seed safety with higher rates of seed-placed nitrogen. (A recent but as yet unpublished study from AAFC in Saskatchewan came to the same conclusion.) Ross McKenzie, lead researcher in the Alberta study, says growers could safely apply up to 60 pounds of ESN per acre in the seed row. This is based on 10% seedbed utilization, which would be a one-inch knife on 10-inch centres - for example. A drill with one-inch knives on 12- or 14-inch centres will need lower ESN rates to maintain the same degree of seedling safety. Seed into moisture. With moist soil conditions, water dilutes the concentration of nitrogen molecules around the seed and seedling. Water also disperses nitrogen molecules throughout the soil, reducing concentrations around the seed. In dry conditions, seed-placed nitrogen fertilizer tends to produce higher concentrations of ammonia and ammonium that can damage young seedlings. Seed placed nitrogen rates should be lowered when conditions are drier than normal. Remember, thinning can occur with any rate of nitrogen placed with the seed, so seed-placed nitrogen, in general, does have an element of risk. The higher the rate, the higher the risk.
Why canopy closure matters Neil Harker, research scientist with AAFC in Lacombe, Alta., spoke at Farm Tech in Edmonton in January about the benefits of canopy cover as a weed management tool. Simply put, plant leaves absorb red light, which is a trigger for germination of light-sensitive seeds. Without red light hitting them, these seeds don't germinate. Dandelions are a prime example. Harker cited a Polish study by Tadeusz Gorski showing that with light, 64% of dandelion seeds emerged in the first four weeks and 86% emerged within eight weeks. But if those weeds were under a crop canopy, 0% emerged over an 8-week period. Annual sow thistle was not included in Gorski's study, but Harker says it is another important light-sensitive weed in Western Canada.
More heated canola than usual As our canola industry grows, on-farm storage will become ever more important. Growers have to prepare to keep canola for 12 months, so "selling" it early won't be an option for everyone. Protecting that valuable crop means checking bins often and turning them over before winter and again in the spring. Canola crush plants will often cycle stored canola every week, even if it's dry and cool, just to make sure it doesn't spoil. Growers may not need to cycle bins every week, but crushers provide a valuable hint. Crushers can't afford to lose a bin. Can you?
Snow cover benefits cleavers Some elevators in Eastern Saskatchewan have reported higher than usual cleaver counts in canola samples. These elevators say they may have to start downgrading more canola unless cleaver counts start to come down. With all the cleavers, some elevators are losing their ability to blend canola to nullify the downgrading effect of weed seeds. No.1 canola must have less than 1.0% of other seeds that are conspicuous and that are not readily separable from canola. This includes cleavers. The cut off is 1.5% for No.2 and 2.0% for No.3. The Canadian Grain Commission says that most of the canola samples downgraded because of "conspicuous admixture" did contain cleavers, but overall, the number of canola sample downgraded for this reason has not been unusually high this year. Click here to see the grading guide. Increase the preseed glyphosate rate for cleavers. With cost-effective glyphosates on the market, increasing the rate of glyphosate in the preseed window is a good option and will result in increased control of both annual and winter annual cleavers.
Soil testing in winter The key is to keep the sample cool, 5°C to 10°C, not frozen, and get it to the lab within a couple days. Don't put it in a tight sealed container. The Soil Analysis Handbook states that "field-moist soil, when placed in an air-tight container, can undergo significant biological changes at room or elevated temperatures" within days. Growers would use winter sampling only if they missed sampling in the fall. By sampling now, growers can get soil test results back in time to modify your fertilizer rates as needed. Remember, whether you use random sampling throughout the field (all mid slope locations), benchmark sampling (going back to same acre each time) or point benchmark sampling (going back to same square metre each time), soil test labs recommend you combine 15 cores and draw your representative sample from that combination. If soil is in icy chunks and too frozen to blend, you may not get a good sample. Labs don't have much experience with samples that started in icy blocks before being melted and blended. Melting such wet soil could start microbial activity and the soil analysis will likely give inaccurately high results.
Coming Events Alberta marketing courses. ACPC is offering marketing courses this month: February 14-17 in Pine Lake, and February 14-March 3 in Drumheller. Click here for more details. SaskCanola regional producer meetings. Dates are February 9 in Melfort, February 10 in Rosetown, February 15 in the Battlefords, February 16 in Humboldt, February 17 in Estevan. Click here for more details and registration information. Combine Clinic. Manitoba Canola Growers Association will hold its AGM and a Combine Clinic on March 1 in Brandon. Click here for more information about the clinic and to register. Only 360 spots are available. Unseeded acres webinars. SaskCanola will host four webinars in March on topics related to unseeded acres. Topics and dates are Fertility March 1, Field management March 3, Disease management March 8, and Weed management March 10. Click here for more details and registration information.
Questions and contacts If you have questions on regional issues, contact one of the following Canola Council of Canada regional agronomists or provincial oilseed specialists:
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:
|
|||||||||||||||||||||||||||||||||
![]() |
![]() |
|