This Update is intended to assist you in your work with Saskatchewan canola growers. We at SaskCanola recognize and appreciate the role you play in providing support to producers and being a key link in the canola value chain.
Now that canola seed is getting into the ground, there are several post-seeding management practices that contribute to a high quality and high yielding canola crop. In this Update, we’ll be sharing a few of those practices with you.
We welcome your questions and comments about canola production practices. Feel free to contact us at any time.
Scouting crop fields throughout the season is essential to maximize yield and profitability. Early season scouting following emergence should be a high priority as this is when we can still "fix" problems.
Start the scouting process by going through last year’s crop records. These records can alert you to potential pest concerns for the upcoming year – when to anticipate different types of weeds, diseases, and insect pest issues.
How to scout
A field may look great from the road but perceptions can change when you take a closer look.
Be sure to carry a scouting kit with you. Important tools include: digital camera, small shovel, pocket knife or pruning shears, plastic bags, ties, vials and labels, rubber boots/boot covers, disinfectant, reference materials, and fact sheets.
Walk the field using a “W” or zigzag shaped approach. This will allow you to capture a more comprehensive overview of the field and potential problems.
Take good notes. Record the different types, locations, and number of weeds, insects, or diseases you found in each and every field, as well as the time and date. Keep this information for future reference.
Survey how individual plants look and determine their growth stage. Crop growth stage is important for determining the appropriate herbicide, and fungicide and insecticide application timing. It can also help for making decisions on replanting and top dress fertility application. Nutrient deficiencies that show up can be remedied early on.
Identify weed species and pressure. Be vigilant in checking fields for any weed growth for the first four weeks following crop emergence. This is critical in evaluating weed pressure and determining whether supplemental control measures are needed.
Find out if there is evidence of an insect problem. Scout fields weekly from pre-seeding to post-harvest, checking both high and low in the canopy and inspecting all plant parts, including roots. It is critical to scout for flea beetle damage when the canola crop is at cotyledon to 4-leaf stage. When insect pest numbers approach action threshold levels, sample more frequently. See the Canola Insect Scouting Guide.
Look for signs of disease. Accurate identification and long-term record keeping of disease information for each field will help growers better predict risk and evaluate, prioritize, and improve disease management programs in their fields. Most soil-borne pathogens strike as soon as the seed begins to take on water. Because seeds can germinate and emerge within 3-5 days under favorable growing conditions, post-planting is an ideal time to begin scouting plants for disease. For more on disease scouting, see the Canola Disease Scouting Guide.
Evaluate if replanting is necessary. Each year fields or portions of fields suffer from poor emergence or from damage after emergence by frost, hail, or insect damage. The crucial question to answer is whether reseeding will result in greater net profitability without significantly increasing risk.
“You can’t underestimate the value of boots on the ground,” says Ian Epp, a Saskatoon-based agronomist with the Canola Council of Canada. “Just after seeding is a good time to start checking your emergence, and scout for flea beetles and weeds. This can all be done in one scouting pass.”
Plants counts – a critical assessment tool
Assessing canola plant stands in every field, every year, will help identify challenges and improve plant establishment practices. A great time to assess is at two- to four-leaf stage once plants are fully emerged.
How to count
By length of row – Use a metre stick and count the seedlings per metre in the row. Take that number and multiply by 100 then divide by the seed row spacing in cm to get plants per square metre. For example, 25 plants per metre multiplied by 100 then divided by 25 cm (10” row spacing) is 100 plants per square metre. (Divide by 10 for a rough indication of plants per square foot.) Repeat.
Using hoops (rings) –Use a hoop with an inside diameter of 56 cm. This is equivalent to 0.25 of a square metre. Count the number of plants inside the hoop and multiply by 4 to get plants per square metre. (Divide by 10 if you want plants per square foot.) Repeat.
NOTE: Do not count volunteers! Plants growing outside the seed row and very early looking plants are likely volunteers. Double check by looking for the blue coat around the seed.
Achieving an optimal plant stand of 5-8 plants per square foot is important to achieving yield targets. Canola crops need 3-4 plants per square foot to maintain yield potential. Plant populations lower than this are more likely to have yield loss. That’s because crops with low plant densities and unhealthy plants are more vulnerable to losses from insects, weed competition and environmental stresses such as frost.
If the stand is spotty and thin, be more conservative with thresholds when protecting the crop from insects, diseases, and weed competition. Also, recording the average number of plants per square foot will help growers improve seeding methods for next year. A key part of stand assessment is to identify why the ideal plant population was not achieved. Was it directly related to the seeding operation? Or did insects, disease, or environmental factors (frost, wind, or flooding) reduce the stand after emergence?
Encourage the growers you work with to take part in this year’s Canola Counts initiative. This survey tool was developed by the Canola Council of Canada with funding by Alberta Canola, SaskCanola, and the Manitoba Canola Growers. It was built to help drive the adoption of plant establishment assessments while tracking progress towards the canola industry production goals of 52 bu/acre by 2025 without adding more acres.
SaskCanola, along with our provincial partners, is offering Plant Count Rings to support growers in reaching their optimal plant densities. To order your no-charge plant counting ring, contact the SaskCanola office at email@example.com.
Tips for early season weed controlWeed management is an essential practice. Weeds are highly competitive, and can quickly use up precious resources - moisture, nutrients, and access to sunlight - that the crop needs. Therefore, the main focus should be on early season weed control. However, as threatening as early season weeds are, a combination of pre-seed weed control and one in-crop application before the four-leaf stage is often enough to manage them.
Benefits of early weed removal in canola are supported by numerous research studies across Western Canada. This control strategy allows the crop to get established, and manages early emerging weeds before they take hold. Once the canopy has closed, the crop should outcompete weeds all on its own. Late in-crop applications at this point do not usually provide any economic benefit.
CCC agronomist Ian Epp says, “Our growing season is starting out as a dry one and there doesn’t seem to be unusual amounts of weed growth, but winter annuals and perennial weeds can take up a lot of moisture for crops to compete with. It’s not too late for many farmers to do a pre-burn run of glyphosate with a tank mix partner. A second post-emergence application will be critical for weed control.”
If pre-seed burn-off is missed, another option is to apply glyphosate or glyphosate with a tank mix partner post seeding and pre-emergence. However, this application window is very narrow. For perennial weeds that have escaped pre-seed and first post-emergence applications but are delayed relative to the crop, pre- or post-harvest glyphosate applications may be a better alternative than a second post-emergence spray, especially if the weeds are delayed enough to avoid seed set prior to swathing.