With the possibility of a few nice weeks after combining and before winter, canola growers will have a few of the following jobs on their minds.
1. Check your plant stand
Field surveys in Alberta in 2011 found that only 54% of canola fields averaged 5 plants or more per square foot, and only 28% of fields had a stand with consistently 5 plants or more per square foot. The ideal plant stand is 7 to 14 plants per square foot, and anything below 5 plants is not reaching its yield potential. A fall count of stems provides an end-of-season assessment of this year’s stand.
To do a stem count, growers can (1) count the stems per metre of 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 to get plants per square foot. Another way is to (2) use a hoop with an inside diameter of 56 cm. This is equivalent to 0.25 of a square metre. Count the stems inside the hoop, and multiply by 4 to get plants per square metre. Then divide by 10 if you want plants per square foot. Repeat counts a few times throughout the field.
2. Volunteer canola management
Canola crops leave an average of 2-3 bushels per acre of seed in the field, or at least 20 times the seeding rate. Swaths flipped and rolled by heavy winds can increase this number significantly. Leaving seeds undisturbed so they germinate in the fall or get eaten by birds and insects is a good way to reduce the volunteer seedbank. When tillage is necessary, hold off for a few weeks if possible to allow predation and seed germination before seeds are buried. Also keep in mind that burying the seed can induce seed dormancy, keeping that canola seed viable longer in the seedbank , possibly for years.
3. Soil tests
With soil analysis results in hand before winter, growers have more time to plan their fertilizer program for next year, to order fertilizer, and to take advantage of reduced pricing opportunities that may occur. For fall results that most closely predict spring residual levels, the ideal time is to take samples when soil temperatures drop below 7 C. Tests done right after combining can indicate whether this year’s crop had enough nutrients. Read more.
4. Weed management
Post harvest is a good time to control winter annuals, biennials and perennials. For best results, weeds must be actively growing with new supple leaf area to target, so give time after harvest or frost for plants to recover. Ideally, you want to apply at a time when temperatures are above 10 C and rising on days with predicted highs above 15 C but preferably higher. Sunshine is as important as temperature. If applying on days where temperatures are at the minimum, it is critical that the sun is shining brightly.
5. Residue management
Spreading residue evenly across the field is critical for accurate and consistent canola seed placement next spring. If the combine didn’t do a good job, harrowing dry straw is an option. Keep in mind that aggressive harrowing can often rip out standing stubble, which you may want to keep in place to trap snow if soil conditions are dry.
6. Scout stems for clubroot and blackleg
Clubroot galls will break down fairly quickly after harvest, but the week after combining can be a good time to pull up stems to check for presence of the disease. Clubroot continued to spread to new areas in 2012. Growers who discover clubroot early can use a combination of machinery sanitation, crop rotation and variety selection to limit its spread and impact on future canola crops. For blackleg scouting, cut stems just above the root crown to look for darkened stem tissue. Ideally, this should happen within a few days of harvest. As the plants die, other saprophytic breakdown — decay — may look like blackleg and confuse the diagnosis.
