|
 |
|
|
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
Story Posted: June 01, 2011 Canola Watch: Fragile stage, Wild oats, Volunteer crop Issues of the week: With most canola seeded and starting to emerge across the western Prairies, scouting becomes a top priority. This is a canola crop's most vulnerable stage, and through scouting you can address threats early. Some growers in Manitoba and southeast Saskatchewan are taking desperate measures to seed canola. This includes aerial seeding. Unless you can get on the field immediately afterward to harrow, this is a high risk practice - especially if the field has any residue cover. Crop and weather update Alberta: Seeding is 85-95% complete. Northeast Alberta needs rain while the central and south regions have adequate moisture. Growers in the south need a week of dry conditions to finish seeding. Crop in the dry regions is slow growing and having a hard time keeping ahead of flea beetles. Frost hit the central region a few times in the past week, with lows of -8 C reported near Calmar. Some growers reseeded. Alberta crop report. Saskatchewan: Seeding is nearly complete for most areas of northern Saskatchewan, but that region needs rain. Frost hit across the north, and some fields have been reseeded. The south has had excessive rain, which continues to delay seeding. Canola seeding ranges from around 70% done in the southwest, to 35-50% around Regina to even less in the southeast. In response to the late season, Saskatchewan Crop Insurance Corporation has extended its seeding deadlines. Please call the SCIC toll free customer service line at 1-888-935-0000 or visit the local SCIC office for specifics for your region. Saskatchewan crop report. Manitoba: After another wet week that included hail, snow and frost in some areas, seeding progress is still slow. Across the province, canola seeding is probably around 30-40% complete, but that ranges from as low as 0-5% in parts of the southwest to 90% in some central regions. Manitoba crop report. Protect canola at this most fragile stage Walk into each newly emerged field and take a scan of hill tops, side slopes and low spots. Did the crop emerge evenly throughout the field and do the plants look healthy? If not, this is when you start looking for clues as to why. Look at the above ground foliage. Are flea beetles the cause of missing plants and heavy damage? Has wind blown seedlings out of the dry ground? Did a hard frost hit the field? Or do yellowed, misshapen and weakened plants suggest herbicide carryover damage? After the surface scan, start digging. Is seeding depth consistent? Do you see cutworms or wireworms? Are the roots healthy? Scouting may be required every day for at-risk crops, especially if a threat such as flea beetles seems to be building. At a minimum get out to each field a couple times per week during this fragile period. Growers may not have all the answers to problems they see. The key is to know your fields and get help when necessary. Below is an example of a one-page scouting check sheet to fill in with each visit to the field.
Start scouting the day after a frost Patience is most important when the extent of damage is questionable and you're struggling with the decision to reseed. It takes several days to allow new growth to be visible, which is the only way to accurately determine the proportion of plants that will survive. Even if 1-2 plants per square foot survive, that thin stand can have more yield potential than a reseeded crop that will take a week to emerge. At this date, a week adds significantly to the risk of fall frost losses. If growers do decide to reseed, click here for steps to speed emergence and shorten maturity. Another reason to wait: With recently emerged crop, growers may find that a sizable percentage of the stand had still not emerged when the frost hit. While losses may be high for emerged plants, the late-emerging plants could fill in to provide a stand with earlier maturity and better yield potential than a reseeded crop. Crop insurance wild card. While 1-2 plants per square foot may be enough for a decent yield, crop insurance may choose to write off a stand that thin. However note that in 2011, SCIC in Saskatchewan created a new establishment plant count category for hybrid canola. The “choice range” for hybrid canola is from 12-40 plants, which is wider than the range for open pollinated canola. If a Saskatchewan grower chooses to leave a crop with plant counts in this range it would be carried to full yield loss coverage. If the grower chooses to reseed a crop in this range, they would be paid the establishment benefit. Check with the local insurance office for the policy in your province.
Wild oats going gangbusters If wild oats are the one problem weed in a Liberty Link canola field, one option is to apply a grassy weed product (Centurion or Select) alone while waiting for emergence of other weeds prior to the Liberty application. But walk the field and take a close look at the weed spectrum before making this decision to ensure that delaying the Liberty application won't lead to reduced control of other weeds that are present. For example, a few cleavers that escape control due to their advanced stage can represent a big problem for canola quality at harvest. Also, since all weeds are easier to control early in the season, small broadleaf weeds are best controlled now. If you're taking the time to spray, putting Liberty in the tank along with the grassy product is probably the most effective and efficient step. Applying the graminicide alone is OK if there really are no broadleaf weeds emerged. But look closely to be sure. Weed control in cool, wet conditions Cool humid conditions are also prime conditions for herbicide injury to the crop. The leaf cuticle (waxy layer) is thinner allowing more rapid uptake of herbicide into the plant and cool conditions reduce the speed at which the herbicide is inactivated in the crop. This can lead to a flash of injury in the crop. This injury is temporary in most cases and once good growing conditions return, the crop recovers and yield loss is rare. Talk to your local product rep to see how they will support the use of their product when applied in cool temperatures. Set expectations according to weather conditions. Volunteer canola as a crop? High risk, low potential! There are many reasons to avoid this: 1. It may violate your contract with the seed company. Is one poor-yielding volunteer canola crop worth risking this business relationship? Talk to the seed rep before investing time and money on this crop. 2. Yield potential is likely to be very poor, probably around 25% of your typical crop based on Manitoba Agriculture, Food and Rural Initiatives experience from 1999 and 2005. 3. The stand is not uniform. Volunteer canola is often way too thick in some places (windrows) and too thin in others. This will means highly variable plant sizes and maturity, creating a challenge for disease control and harvest timing. 4. No seed treatment. Flea beetle losses could be huge. Will it pay to spray insecticide on a crop with low yield potential? 5. No fertilizer. Canola has high nutrient requirements. Without a fertilizer top up, yield potential is very low. Is this crop worth a fertilizer investment? 6. No crop insurance. In Manitoba, MASC will not insure a volunteer crop but growers are still eligible for excess moisture insurance. SCIC in Saskatchewan will not insure volunteer canola. If you can control the volunteers and seed a proper crop before the crop insurance deadline, this is the better option. Check with your local insurance agent for details. 7. F2 traits uncertain. Second generation canola (F2) from hybrid seed will not have hybrid vigor and not all plants will have inherited the herbicide tolerance trait. The first spray will wipe out these susceptible plants. 8. High blackleg risk. On fields that had blackleg last year, the disease may have already infected seedlings. Early season fungicide may be required to keep the disease from wiping out the volunteer crop and preventing a huge spike in blackleg inoculum for future canola crops. 9. Rotation risk. Given the lower yield potential for canola on canola, leaving the volunteer crop may contribute to an increase in many pests and diseases. This has the potential to compromise the economic viability of canola on those fields in future years when conditions and yield potential may be much better. Harrowing essential after aerial seeding If it's too wet for a floater, it will be too wet for harrows and sprayers. After broadcast seeding, including aerial seeding, fields must be harrowed to loosen the soil surface and provide seed to soil contact. Canola seed is very light and does not embed into the soil, even if dropped from an airplane at high speed. This is especially true for seed broadcast onto stubble. Crop residue can be a barrier preventing seed to soil contact. Seed applied by airplane or helicopter will not push through this layer. Click here for last year's article on aerial seeding, which included comments from an experienced applicator. Do you see sulphur deficiency symptoms?
A top up with ammonium sulphate may be required in fields that have not received regular sulphur applications. Sulphur content can be highly variable across a field, so while an aggregate soil test may show adequate amounts, many areas of the field could actually be deficient. Comparing tissue tests from canola plants in healthy versus deficient looking areas of the field can help determine whether sulphur is the cause. Contact a soil test lab to get its instructions on how to take and submit a tissue sample. (The image below is one lab's guideline.) Do tissue tests early enough in the season to provide ample time to take corrective action. Sulphur top ups should be applied before first flower and the earlier the better. Even if visual analysis or a tissue test suggests an early sulphur deficiency, a top up may not be necessary if you have been applying good rates of sulphur fertilizer. In this case, the sulphur may have simply leached a little lower in the soil profile. Canola may be able to recover on its own from early deficiency when its roots grow enough to access these sulphur reserves.
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.
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
|
|
|
|
