We all know what a difficult summer this has been for growers. With drought and prolonged heat in most parts of the province, crops are maturing quickly and seed heads are not filling. Yields are expected to be lower than usual, but there is good news with high canola prices.
Many growers have started to harvest and now is the time to remind them about ways to maximize yields, despite less than ideal growing conditions. This update focuses on canola harvest management and contains information you can use when working with customers to help them get as much as they can out of their canola crop.
Growers can potentially maximize both yield and quality by waiting until the canola crop is at 60% seed colour change (SCC) on the main stem to swath. Targeting 60% SCC on the main stem for swath also enables many growers to delay the start of swathing on their first fields until at least 30-40% SCC to capture most of the yield potential and seed quality.
“To get the most yield, 60% plus on seed colour change is needed,” states Shawn Senko, Agronomy Specialist with the Canola Council of Canada. “Some low spots will still have a decent yield and the hills will be shelling, but it’s still important to hang on because a lot of areas won’t be ready to go.”
Tips for assessing seed colour change:
Start inspecting canola fields approximately 10 days after flowering ends. The end of flowering is defined as the stage when only 10% of plants have flowers.
Take time to assess a field. Sample various parts of the field to make an accurate assessment of the overall maturity of the crop. Stand on the road or in the back of your truck box to compare low-lying areas to higher elevated areas of the field to note early maturing and late maturing parts of the field.
Walk out and sample at least five plants in each of those areas. Isolate the main stem and open pods from the bottom, middle and top of the stem. Seed in pods on the bottom third of the main stem mature first and will change colour much sooner than seed in the pods of the top third of the main stem.
Use swath timing images to assist in determining seed colour percentage on the main stem. Most of the seeds in the top pods will be firm and roll without being easily crushed between the thumb and forefinger. Also include seeds with small patches of colour (spotting).
For fields that has low plant populations with many secondary branches, assess the main stem and side branches to ensure seeds are still green are firm with no translucency.
Once all areas are sampled, calculate the average SCC for that field.
Continue inspections every 2-3 days until the field is ready to swath. Average SCC will typically increase about 10% every 2-3 days. Under hot, dry conditions, SCC can occur more rapidly. When conditions are cool, seed colour change can take longer. See the Canola Swathing Guide for more information on assessing seed colour change.
Swath or Straight Cut?
Both swathing and straight-cutting are effective ways to manage canola harvest. Each method has advantages and disadvantages.
Given pod drop issues due to environmental stress this year, swathing may be the best and least risky option to manage extreme variation in maturity. Uneven crops can also be left for straight combining when managed well. While early maturing plants may start to shell out, late maturing plants have more time to mature.
Rapid crop advancement due to hot, dry conditions can mean the driest pods become brittle in a short amount of time, which is risky for plants without pod-shatter tolerance. Hot, dry conditions could reduce the ability for late seeds to fill out before shriveling up. Swathing earlier than 60% SCC is probably the wrong move, especially if the later areas have higher yield potential. Plants in lower areas could also be rooted into moisture at depth, which means seeds could still be filling despite dry conditions.
Varieties with a degree of shatter tolerance can make it easier to delay swathing, letting the least mature areas catch up as much as possible. Keep in mind that mature canola can be more prone to blowing and damage because it is fluffier and difficult to anchor in the swath.
If growers prefer to straight-cut, the questions then is whether to let the uneven canola crop ripen naturally or spray a harvest aid product. With an uneven crop, desiccation may be required to dry down weeds and those very late canola plants to facilitate straight combining. Hold off on desiccation as long as possible to let the crop mature, then go in with desiccant a few days before harvest. More information on using pre-harvest aids on uneven fields
Swathing has no clear advantage over straight combining for lodged canola. It often comes down to personal preference.
Senko emphasizes, "Whether you choose to swath or straight cut comes down to time management at harvest, but there’s no perfect answer. What’s going to work for you? What’s less risk? Plan your harvest. If you think we won’t get at harvesting canola quickly, straight cutting might be better.”
Grasshoppers can thrive in hot, dry conditions. If grasshoppers are a problem this year, be sure to scout to assess whether thresholds have been reached (threshold values found here). And don't forget to consider pre-harvest intervals. See the Spray to Swath Interval Calculatorto help you determine the minimum number of days that must pass between product application and cutting the crop by swathing or straight-cutting.
Minimizing Combine Loss
"Canola producers can lose higher than usual amount of yield as harvest loss if the combine isn’t adjusted properly," says Senko. “Losses will double this year – 2 bushels of loss will be $40 on the ground. You need to catch every bushel because you don’t want to have more than a 2% loss.”
Here are tips to measure combine loss and make adjustment to limit those losses and put more canola in the bin.
Check for leaks. Losses do not always come out the back end. Before making any adjustment to cylinder speed, concave spacing, fan speed or sieve spacing, check over the combine to make sure you don’t have any leaks. Look for holes and cracks on the pickup, feeder house, elevator, shoe seals, separator covers, and the grain tank.
Feed the combine properly. Rotaries work best with a narrow windrow. Conventional walker combines work best with a wider swath that creates an even mat over the full width of the cylinder and walkers. In PAMI research conducted by Les Hill, where an even mat resulted in losses of 2.2%, losses rose to 7.5% when the bulk was concentrated down the middle and 12.3% when the bulk was on one side. The simple reason is that air can’t move through the mass and the mat carries unseparated grain out the back.
Slow down. It may take just a small decrease in speed – say 0.2 or 0.3 mph – to provide a significant reduction in losses, Hill says. The loss curve tends to remain fairly flat until ground speed reaches a critical point when combine capacity is taxed, then the loss curve can rise steeply. “When a combine hits that wall, a lot of the time it’ll start dumping grain out the back,” Hill says. When testing for your combine’s sweet spot, reduce speed in small increments and keep throwing out the pan to check losses.
Make adjustments. If losses are far too high, try starting out with the manual’s suggested settings and go from there. Change only one variable at a time and check losses in between so you can be sure what has either helped or hindered the loss situation. Check that automatic settings are properly calibrated. For instance, if the chaffer setting on the monitor says 18mm, take a ruler and check that the chaffer spacing is in fact 18mm.
The CCC’s Combine Optimization Tool walks the user through a step-by-step process to diagnose combine issues- whether losses, productivity, or sample quality.
“Making sure your combine is in prime working order can make a big difference to yields,” stresses Senko. “The settings used in a normal year won’t be the same as this year. There will be seed size differences and different biomass going through the combine.”
Harvest is the ideal time to check for clubroot and blackleg.
This year, SaskCanola and the Saskatchewan Ministry of Agriculture are offering free testing for both clubroot and blackleg to Saskatchewan canola growers.
Clubroot: Clubroot soil testing can be used to detect low levels of the clubroot pathogen. Early detection and proactive clubroot management strategies help keep spore levels low and minimize yield losses. As part of this program, a grower or an agronomist can request a clubroot soil sampling bag, collect soil from the intended field and submit it for testing at no cost. More information
Blackleg: This year, we have expanded our disease monitoring program to include blackleg. The first 200 registered canola growers who are apply are eligible for a FREE blackleg race ID test.
Race testing blackleg infections can help growers and agronomists select the most effective blackleg resistance genetics. SaskCanola will cover the testing cost, valued at $190 each.