Canola in the Pacific Northwest: An opportunity crop
The Pacific Northwest is different from any other canola production region in the U.S. and Canada in that both spring and winter canola can be grown successfully, opening the door for crop rotation opportunities with canola in a wide range of environments and cropping systems. Spring canola production is concentrated in the annual cropping regions of eastern Washington and northern Idaho, and all of Montana. Winter canola is grown in lower rainfall, crop-fallow regions of Idaho, Oregon, eastern Washington, and scattered areas of Montana, as well as the Willamette Valley in western Oregon. It is also utilized as a deficit irrigation crop where water is limited, e.g. deep-well areas of eastern Washington.
Yield potential of winter canola is often cited as double that of spring canola; however, that figure can vary widely depending on several factors, primarily available water during the growing season. In the low rainfall, wheat-fallow regions, winter canola can yield from 1,500-3,000 lbs/acre (30-60 bu/acre). Deficit irrigated winter canola average yield is 4,000 lbs/acre (80 bu/acre) while in the Willamette Valley of western Oregon yields of 4,000-5,500 lbs/acre (80-110 bu/acre) have been reported. Spring canola may only yield 1,000 lbs/acre (20 bu/acre) or less in a dry year, and with higher rainfall average can yield up to 3,000 lbs/acre (60 bu/acre).
If you have not yet tried canola, keep in mind when working through the decision making process that there is no one ‘right’ answer to a lot of questions you may have about growing canola. It is important to network with other canola growers and learn from their experiences, go to field tours and workshops, and peruse canola production information on this website and others. ‘Canola is an opportunity crop’ is a common statement from seasoned canola growers – and can be defined by economics, planting conditions, crop rotation, and other factors, and when most or all of those line up, take advantage of the opportunity!
The information below contains strategies, links to publications, and other insights that can be utilized whether you are a first-time or experienced canola grower, crop consultant, or input supplier. It is not intended to be comprehensive, but rather an evolving source of information over time. During the next 6-12 months this information and more will be compiled into a PNW Canola Production Guide. If you have suggestions for additional information to include, or are willing to share anything you have learned from growing canola please email email@example.com.
Once the decision has been made to include canola in your crop rotation, what are the next steps to get started? The following statement from a canola grower in eastern Washington sums up a bigger picture perspective about canola production:
“Growing canola requires a different way of thinking, from a systems approach - chemical systems, cropping systems, rotational systems.”
Why Grow Canola? Benefits
The benefits of growing canola are well documented in the Pacific Northwest. While not an exhaustive list, the following benefits are often listed by farmers for reasons they started and continue to grow canola in the PNW:
- Crop rotation – canola is a broadleaf crop that introduces diversity, particularly in the cereal-dominated cropping systems common to the PNW.
- Chemical rotation – canola provides an opportunity to use herbicides that aren’t used in cereal rotations.
- Improved weed management – the ability to use different chemistries, and different timing of weed control than in a monoculture rotation can significantly improve control of problem weed populations and decrease the chance of herbicide resistance.
- Yield increase in subsequent wheat/cereal crop – while there are a few reports of reduced yield in crops following canola, most growers comment on improved yield the year after canola, and often two years after canola.
- Economics – with canola markets holding fairly steady compared to other commodities such as wheat and garbanzo beans, most enterprise budget calculations end up with a positive bottom line when canola is in the crop rotation.
- Break disease and pest cycles – canola serves as a ‘break crop’ in wheat and other cereal rotations where disease and pests have built up to economically damaging levels.
- Irrigation timing – in deficit irrigation systems, canola needs water at different times than when potatoes or wheat need water
- Improved soil structure and health – the taproot of canola can break up tillage and hard pans, and the entire root system is very efficient at taking up nutrients that are not accessible by wheat roots.
- Snow capture and residue decomposition – standing canola stalks are great for catching snow, and also decompose fairly readily, allowing for easier no-till seeding.
- Increased water infiltration – the taproot opens up more channels for water to move down into the profile, reducing the chance of erosion and improving soil structure for subsequent crops.
- No need to purchase new equipment – while modifications may need made to existing equipment, you can use what you do for wheat and other crops.
- LOCAL demand – having processors in MT, OR, and WA reduces transportation cost for many growers in the PNW.
The single most important detail to know before planting canola is the herbicide history of the field, preferably from at least 3-5 years prior. Canola is very sensitive to Group 2 herbicides, which include ALS inhibitors imidazolinone (IMI) and sulfonylurea (SU). In general, IMI’s degrade faster at higher soil pH while SU’s persist longer in higher pH soil. Fortunately, there are herbicide residual tolerant varieties available but the field history still needs to be known to make accurate variety selection decisions. If the ground has been recently acquired and the chemical history is unknown, take the time to conduct a bioassay before committing to planting an entire field to canola.
- Plan ahead! A bioassay should be done a minimum of 30 days ahead of seeding to be able to observe any plant injury and allow time to make variety selection and purchase decisions.
- Collect several soil samples from the field in question and mix well. Do the same from a field that is known to be free of Group 2 herbicides. Samples should be taken from the top 3” of soil unless there has been cultivation to a deeper depth. Keep the two field samples separate. Collect enough soil to fill several 4” pots for each field.
- Plant susceptible and herbicide tolerant canola seeds in both sets of pots and place in a sunny window or greenhouse. Keep the soil moist but not waterlogged.
- Let the plants grow for 2-4 weeks and observe any symptoms on leaves, stems, and roots such as yellowing, stunting, or other abnormalities.
- Once a determination has been made about the presence or absence of residual herbicide, the next step is to choose the variety that will potentially perform best on your farm.
- Rotational Restrictions for Canola (pdf, WSU, applicable to PNW)
- Herbicide Carryover Info sheet (pdf, NDSU)
- Herbicide Classification poster (pdf)
- Photo Gallery - examples of a bioassay showing residual herbicide injury symptoms under Diagnostics
“Always question your fieldman: ‘what windows will I close if I use that chemical?’” – Steve Swannack, Lamont, WA
Winter and spring canola genetics have improved considerably in the last 5-10 years. The number of hybrids and open-pollinated varieties available to growers has expanded to include a range of conventional and herbicide-tolerant choices, and specialty canola (high oleic and high omega). One example is the development of Clearfield residual tolerant canola, which can follow Clearfield wheat varieties that are popular choice for Pacific Northwest growers (see photo).
Technology traits to handle residual herbicides in the soil are SURT = SU-Residual Tolerant (not IMI tolerant), and Clearfield (CL) = IMI residual tolerant (most are also SU residual tolerant).
The classification of non-GMO and GMO canola is as follows:
- Roundup Ready (glyphosate tolerant)
- Sulfonylurea-Roundup Ready (SU and glyphosate tolerant)
- Liberty Link (glufosinate tolerant)
Take a look at variety trial data from the PNW to see which entries perform well over several years, attend canola field tours near your farm, and talk to experienced canola growers in your area to see what varieties have done well for them. Tailor your final decision based on residual herbicides (if present), crop rotation, performance, cost, and availability. Note that in some cases seed supply can dwindle rapidly based on high demand in other parts of the country and in Canada.
***Note that ID, OR, and WA all have requirements in place from the Department of Agriculture in each state in regards to all canola seed sold having documentation (e.g. phytosanitary certificate, bag tag) declaring the seed to be certified black leg free. Do not purchase seed that does not have the proper documentation.
- Seed Supplier page for availability of spring and winter canola from PNW outlets
- PNW and National Variety Trial Results page to aid in making variety selection decisions
- Video Library to hear grower experiences and production strategies
“We have never been disappointed with canola in our rotation.” – John Hinnenkamp, Colfax, WA
The decision to grow canola can be intimidating because it is so different from cereal crops, or even pulses, hay, and other more familiar crops of the PNW. Economics matter, and the primary question to answer is if including canola in rotation will improve your bottom line? With other commodities struggling to remain profitable, canola certainly is worth considering. A simple exercise to compare the costs and returns of including canola vs. another crop in rotation is an enterprise budget. WSU has developed spreadsheet-based enterprise budgets for low and intermediate rainfall regions that allow input of as little or much information as you’d like, e.g. fertilizer costs, land costs, yield, and market price. Another publication has a chart that directly compares the feasibility of winter canola in rotation with winter wheat in intermediate rainfall areas.
The opening of canola processing facilities in MT, OR, and WA in the last 5-7 years has been a game changer in the economics of canola production in the PNW by providing a local market that reduces transportation costs for many growers. The facilities are also sourcing locally grown canola as much as possible, and that is often translating to a steadier market price than elsewhere in the U.S. and Canada.
- Economics section of the PNW Canola Publications page
- Local Cash Bids & Marketing page
- Video Gallery (see the Canola Marketing and Grower Assessment of Economics video in the ‘Other’ category)
“Four out of five years I make more money off my canola than my wheat.” – Curtis Hennings, Ralston, WA
Equipment: When it comes to planting canola, the old adage ‘one size fits all’ does not apply to equipment. Whether you have a disc drill, an air seeder, a singulating planter, or pretty much any make and model, it can be used to plant canola. The ‘right’ choice is what works best with the tillage system and soil on your farm. The objective is uniform, consistent seed placement to achieve an even emerging stand. *** A critical factor is that seed needs to be placed INTO moisture (not just to moisture) so there is moist soil above and below the seed. Talk to other growers, attend field demonstrations of equipment, and check online canola forums to learn about what drill modifications other growers have tried that may improve seed placement and stand establishment. Following are examples from several PNW canola growers of what they have observed and learned over the when it comes to equipment and seeding:
- “It is important to have a drill/planter configuration that clears residue from on top of the seed row. This results in better seed to soil contact, and once the seed germinates it has a better chance of the growing point being below or at the soil surface.”
- “The two things that I’ve learned regardless of the drill I’ve used is to go slow, and to calibrate!”
- “I found the coulters on one of my drills were too deep on the downhill side, causing slow emergence. I switched to my double disc drill that worked much better on the hills with more even emergence.”
- “We built a drill that has 5” paired row mid-row fertilizer application, and 5.5” wide rubber packer wheels. The shanks are on 12” centers and 4’ apart on each rank. The drill works well on level ground and steep slopes.”
- “We farm in low rainfall, wheat-fallow country with volcanic soils. We’ve got a Bourgault on 20” and a ConservaPak on 9” row spacing, and find that both work best without closing wheels – that avoids too much soil packed on top of the seed row. The 20” row spacing was wider than we were comfortable with but it was amazing to see how the canola branched out and filled that space. The yield was less with the 20” spacing but not significantly so.”
- “I’ve been working on trying to simulate singulation with my AgPro drill and ended up getting smaller diameter rollers off a Seedmaster drill, then we had a machine shop cut out a “blocker plate” that goes between the rollers.”
Winter canola: With changes in fertilizer timing strategies and canola genetics in the last several years, the window of seeding has widened considerably in many areas of the PNW, ranging from mid-July to early September (see Fertilizer Management below). For growers in low rainfall, wheat-fallow systems, depth to soil moisture is often the deciding factor for seeding date. If a timely rain occurs during the July-September window, it is not uncommon to stop harvest of other crops and plant canola while the opportunity exists. With warmer temperatures extending into September in recent years, some growers in higher rainfall areas are seeding into late September. Jim Davis, a canola researcher at University of Idaho, recommends seeding before September 10 in the Palouse of eastern WA and northern ID. That allows enough time for above and below ground growth to be sufficient to survive the winter. In the Willamette Valley, winter canola is seeded mid to late September, while in northcentral Oregon canola is typically seeded by early September. In Montana, target planting winter canola in August.
Dual-purpose canola: If winter canola will be grown for late summer/early fall grazing, it will need to be planted in June, and preferably without fertilization. Before grazing take tissue tests to confirm nutrient concentrations are safe for the cattle. For timing of grazing, the ‘twist and pull’ test is when it is safe to turn cattle on to the field – that is when the plants in the area to be grazed are difficult or impossible to twist and pull out of the ground. Be sure to provide a low quality, dry feed source for the cattle, preferably placed between the canola and water source to encourage consumption to offset the ‘richness’ of the canola forage. For more information about dual-purpose canola see the PNW Canola Publications page and the Video Gallery (Farm Perspectives of Canola Production in High Rainfall video (beginning at 22:30 mark in Grower Experiences tab).
Spring canola: Spring canola is typically seeded in April, or as soon as equipment can get in the field after snowmelt. Older production guides recommended soil temperatures of 50⁰ before seeding, but more recent research and improved genetics have allowed seeding in cooler soil temperatures. Germination will be slowed when soil temperatures are below 45⁰ and will require vigilant scouting for insect pests, specifically flea beetle, until the first true leaves form. Seeding later in May is not recommended as there is an increased potential for hot temperatures by the time the canola is blooming. Data from USDA-ARS spring canola field trials in eastern Washington state during a 9-year period showed yield decreased 43 lbs/day each day seeding was delayed after April 12. A grower in Spokane County, WA recorded spring canola yield from fields that had a range of planting dates in 2017, and the downward trend was very similar to the USDA-ARS study (see photos below).
Plant population: A target population of at least 5-8 plants/ft2 is recommended for spring canola, and 4-5 plants/ft2 for winter canola. Studies in the PNW and Canada and anecdotal evidence from growers show an average germination of 50-60%. Thus, to attain 5 plants/ft2, plan on calibrating for seeding 10 seeds/ft2. If seedzone water is ideal and the weather outlook is favorable, mortality can be much less. Canola has a compensatory growth habit and will branch out to fill space; however, seeding rates that are too low can result in increased competition from weeds and reduced yield potential.
Seed size can vary widely between open-pollinated varieties and hybrids, from bag to bag, and from year to year so it is important to factor in thousand seed weight (TSW) when calculating seeding rate. The TSW is printed on a tag on every bag of commercial canola seed. The Canola Council of Canada has developed calculators to set seeding rates and plant stands that match seed size, risk factors and estimated seed survival. Check out the calculators on the Canola Council of Canada site. In the near future, seed companies will package bags of canola seed based on a specific seed size, to plant a certain number of acres.
Drill calibration: Don Wysocki, Oregon State University Extension Agronomist, offers these recommendations for drill calibration:
Planting the proper amount of seed is very important. To achieve the proper sowing rate your drill must be properly calibrated. Having a scale that can weigh small amounts (e.g. kitchen scale) is very helpful. The process for drill calibration is specific to the type of drill, but the principles are the same - you want the drill to deliver the desired amount of seed per unit length of row adjusted for row spacing by whatever metering system the drill is using. Air drills use fluted rollers, conventional JD drills use fluted blocks in cups, etc. We advise that you follow the manufacturer’s instructions and settings for calibration. Some drills have sprocket settings or transmissions for various drive speeds. Be sure to know the correct setting for small seeds. For instance JD HZ drills have interchangeable sprockets that change drive speed. A shield cover must be removed to get to them. With the faster drive speed very little flute (<1/8”) shows in the feed cup, at the slow speed about 3/8” shows for the same seeding rate. It’s also important on fluted drive drills to check that the same amount of flute shows on every cup. Often, first-time canola growers seed more than the target, because of inexperience seeding small seeds. Anyone with experience seeding alfalfa usually knows the issue. Refer to the Canola Council of Canada calculator referenced above, and the presentation by Autumn Barnes listed below for more details on calibration.
Row spacing: The most common row spacing for spring canola is 7-12 inches, while winter canola is typically planted at wider row spacing, from 12-28 inches. A 3-year study by University of Idaho near Genesee, ID showed no yield difference between 10” and 20” row spacing in winter canola. Similar results were found with a spring canola row spacing study at WSU with 14” and 28” row spacing. However, wide row spacing is not recommended for spring canola due to weed competition before canopy coverage is complete.
Seeding depth: Recommended seeding depth for winter and spring canola in the PNW is 0.5”-1.5”. If moisture is deeper than 1.5” and the drill is capable of placing seed deeper, it is preferable the seed is not covered with more than one inch of soil. Again, the key is to place seed INTO moisture so the soil above and below the seed has sufficient moisture for the seed to imbibe for germination and root development.
Seeding speed: Seasoned canola growers often cite drill speed that can make the difference between a great stand and a disaster. Target 3-4 mph, check seed distribution and adjust the speed if needed. Faster speed may cause bounce of the drill, resulting in uneven seed distribution and seeding depth.
- Successful Stand Establishment - a presentation by Autumn Barnes, Agronomy Specialist with the Canola Council of Canada during the PNWCA Canola Workshop in Great Falls, MT
With canola in rotation, it is important to develop a soil test and field history-based fertilizer management plan that accounts for residual nutrient carryover in your rotation. The ‘4R’ system, right source, rate, placement, and timing, is key to maximizing yield and fertilizer uptake. Due in large part to the root structure of canola that includes a taproot and many fine root hairs, canola is very efficient at accessing more and deeper nutrients than wheat.
Although nitrogen and sulfur are commonly cited in the PNW as the most essential required for successful canola production, several other nutrients may also be deficient on soil tests. In general, fertilizer recommendation are as follows:
- Nitrogen: 7 lbs N/100 lbs of expected yield*, minus soil test N and expected mineralization
- e.g. for 3,000 lbs expected yield and 70 lbs soil test N: 3,000 x 7 lbs N/100 lbs = 210 – 70 = 140.
- N fertilizer recommendation = 140 lbs/acre minus mineralization (refer to soil test).
* note that this amount will vary year to year depending on growing season precipitation, stand establishment, and other factors but 7 lbs is the average based on years of research in the PNW
- Sulfur: by soil test; 20-30 lbs S/acre, not to exceed 40 lbs; recommended N:S is 7:1
- Phosphorus: by soil test, typically starter rates
- Potassium: not often required in much of the PNW; refer to soil test
- Boron: by soil test; usually ½ to 1 lb/acre.
- Other: there are not definitive recommendations for micronutrients in the PNW. Micronutrient packages from crop input suppliers are becoming more commonplace; be sure to ask for results of performance trials conducted in your area as part of the decision making process. Studies are underway at WSU and UI to determine responses to micronutrient applications in winter and spring canola at different times during the growth season.
Fertilizer should not be applied with the seed. Separation of at least one inch and preferably two inches between the seed row and fertilizer is recommended. Researchers at WSU have looked extensively at canola root response to different sources of N fertilizer banded below the seed. When the taproot encounters a fertilizer band, lateral roots are initiated, and there is apical dieback and root hair death (see photo). Urea resulted in significantly more damage to roots than ammonium sulfate and urea ammonium nitrate.
For winter canola, a common practice is applying starter fertilizer at planting, followed by streamjetting one-third of the total fertilizer in November and the balance in the spring. Too much fertilizer early in the growing season can cause excessive fall growth, potentially exposing the growth point and increasing susceptibility to early fall frost and winterkill. Side or mid-row banding fertilizer at planting is common in spring canola production, provided there is sufficient separation distance between the seed row and band.
A systems approach to weed control in rotations with canola includes planning crop and chemical rotation to address immediate field-specific weed pressures, minimizing application of long-term herbicide carryover (particularly Group 2s), and avoiding development of herbicide-resistant weeds. As mentioned in the Variety Selection section above, development of residual herbicide tolerant and herbicide tolerant varieties has expanded the opportunities to rotate chemistries, in turn reducing or eliminating the potential for herbicide resistant weeds. The following is a partial list of herbicides labeled for use in canola in the PNW. Always read and follow label directions and restrictions for all products before using.
- Preplant Incorporated: Sonalan, Treflan
- Postemergence grass: Assure II, Poast, Select
- Postemergence broadleaves: Stinger (Canada thistle)
- Herbicide resistant systems:
- Liberty Link (glufosinate)
- Roundup Ready (glyphosate)
- Clearfield (imazamox)
Develop an Integrated pest management strategy that includes scouting fields regularly and knowing the life cycle of the more common pests. Populations can increase or decrease quickly which will impact treatment decisions. Insect pests and birds can be observed in canola from emergence to maturity but may or may not be at economic thresholds or at a damaging stage of their life cycle. Refer to the resource list at the bottom of this section, as well as the Pest & Disease Management section of the PNW Canola Publications page for more detailed information about identifying pests, life cycles, and determining a treatment plan.
The most common insect pests that may reach economic thresholds during the winter and/or spring canola growing season in the PNW are:
- Cabbage aphid
- Cabbage seedpod weevil
- Flea beetle
- Diamondback moth
Other pests observed but not often at treatment levels are:
- Lygus bug
- Blister beetle
- Horned lark (bird)
When scouting fields for pests, be sure to also scout for beneficial insects such as:
- Ladybug beetles
- Parasitic wasps
- Ground beetles
- Damsel bugs
We have heard accounts from many PNW canola growers that opted not to apply insecticide after discovering a substantial beneficial population, e.g. ladybug nymphs feeding on aphids, and the beneficials ended up providing sufficient natural control. On the flip side we also have reports from growers that spray every year as a ‘precaution’ against insect pests, without scouting first. Beneficial insect populations will not have a chance to build when insecticide is applied every season. The decision to spray should be made after scouting regularly and referring to the economic thresholds for a particular insect pest. If spraying is warranted, apply in the evening or early morning, and use a selective insecticide when possible. If there are honey bee hives near or at the field to be sprayed, contact the apiarist in advance of application so they have time to move or cover the hives if desired.
Canola is a self-pollinated crop, so only hybrid canola seed production has special pollination requirements. There is ample anecdotal evidence of increased yield when pollinators are present in canola. Canola is an excellent forage source for bumblebees and other native bees, honey bees, and other pollinators. Beekeepers are taking note of the increasing canola acreage in the PNW, and the value of having their honey bees forage in canola fields after being in almond orchards. The Honey Bee Health Coalition and the U.S. Canola Association, along with input from PNW university experts, developed a publication “Best Management Practices (BMPs) for Pollinator Protection in Canola Fields” for growers and beekeepers, and a link to the Honey Bee Health Coalition can be found on the Helpful Links page.
Recent research at WSU has focused on landscape and environmental effects on bee and other pollinator communities. The research team is also investigating if there are differences between canola varieties in nectar quality based on water availability, and if that influences pollinator preference to particular canola varieties. Abstracts from 2018 and 2019 results are on the PNW Canola Publications page. Check out the Bees and Canola section on the Health Benefits page for more interesting facts, and the Photo Gallery for images of pollinators!
- Video Gallery – “Insect and Disease Management for Oilseed Crops” (Production Systems and Strategies)
- Pest and Disease Management section of PNW Canola Publications page
- Canola Insect Pests (pdf) – presentation by Jim Davis, UI
- Identifying and Managing Insect Pests of Canola (pdf) – presentation by Dale Whaley, WSU
- Cutworm Pests of Crops on the Canadian Prairies: Identification and Management Field Guide(pdf)
- Beneficial Insects in Your Crops (Western Canada)
- Insecticide Classification Chart (pdf)
- Photo Gallery for images of Pests, Pollinators, and Diagnostics
Diseases common to canola in other regions of the U.S. and Canada have not really gained a foothold in the PNW, primarily due to the Mediterranean environment, crop rotation intervals, and seed treatments that contain fungicide. Black leg, rhizoctonia and sclerotinia have all been observed is some areas of the PNW. Canadian canola growers are dealing with clubroot, a disease that has the potential to be devastating, and one that PNW growers near Canada are keeping close tabs on every year. When black leg established in Canada it was attributed to canola growers tightening their rotations to having only one, or no, crops between canola. The recommendation is at least 3, preferably 4 crops between canola in the same field to reduce the chance of black leg. All seed sold in ID, OR, and WA requires a certificate declaring the seed disease-free; do not purchase seed that does not have a certificate.
- Insect and Disease Management for Oilseed Crops (Video Gallery – Production Systems and Strategies)
- Pest and Disease Management section of PNW Canola Publications page
- Fungicide timing and rate to control blackleg disease in winter canola (pdf) – OSU research
- Pacific Northwest Plant Disease Management Handbook
- Fungicide Classification poster (pdf)
- Photo Gallery for disease images
Diagnostic Labs in the PNW
The land grant universities in the PNW all have diagnostic clinics at the main campus and/or branch campus locations. The diagnosticians are expert at identifying plant, pest, and disease questions that arise particularly during the growing season but also year-round. Click on the link to the clinic nearest you to find out details such as fee schedules and how to submit samples.
- WSU-Pullman: https://plantpath.wsu.edu/diagnostics/
- WSU- Puyallup :https://puyallup.wsu.edu/plantclinic/
- MSU: http://diagnostics.montana.edu/
- OSU Corvallis :https://bpp.oregonstate.edu/plant-clinic
- OSU Hermiston: https://extension.oregonstate.edu/harec/plant-pathology-diagnostic-laboratory-services https://extension.oregonstate.edu/harec/plant-pathology-diagnostic-laboratory-services
- Univ of Idaho Parma: https://www.uidaho.edu/cals/parma-research-and-extension-center/plant-pathology
- Univ of Idaho Twin Falls: Clinic coming soon!
The easily recognizable growth stages of canola are:
- Bud initiation/bolting
- Stem elongation
- Pod fill
For winter canola, a comment often heard from first-time canola growers is “I’m sure glad someone told me the canola would look and smell horrible going into winter!” Once a hard frost occurs, the leaves will begin to die back, with the aroma of rotting cabbage (sulfur-like). The canola vernalizes, like winter wheat, before resuming growth in the spring. Canola is very different from wheat, and it is worth spending more time in the field at all growth stages to become familiar with what looks ‘right’ and what may be something that needs attention, e.g. nutrient deficiency, sweeping for pests. Canola emergence can be sporadic depending on weather conditions and seeding uniformity, but always seems to fill in spaces with the compensatory growth habit. Most residual herbicide and nutrient deficiency symptoms will be visible by the 4-6 leaf stage, and as late as bolting and stem elongation.
Canola flowering can last from a couple of weeks to six weeks depending on weather conditions, specifically the temperature. If a frost event occurs during flowering, the canola plant will typically droop over, and then will grow upright again as the temperature warms. This causes the stalk to have an ‘S’ shaped curve but does not affect yield unless there are continuous frost events. Flowers open during frost events will abort and not produce a viable pod. Similarly, temperatures above 85⁰F during flowering will cause aborted pods.
If questions arise at any point during the growing season, contact your local Extension service, neighboring canola growers, crop input supplier, university staff, or other regional canola experts.
Kansas State University has developed an excellent poster of canola growth and development with key management items to be aware of during the various growth stages (see Resources below). Although the information is specifically for winter canola, a lot of it is also applicable to spring canola.
A few methods for a rough estimate of yield once pod formation is complete:
- # of pods on main stem x 40 = winter canola yield in lbs/acre
- # of pods on main stem x 50 = spring canola yield in lbs/acre
- "hands of pods on main stem" = 5 bu/acre (250 lbs/acre) per hand
- PNW Canola Publications
- Photo Gallery
- Canola Growth and Development poster (pdf, Kansas State University)
“You need to be willing to put time into learning about the crop and not treat it second-hand.” – PNW canola grower.
Winter canola is harvested from late June through July, and spring canola in July-September, and some years into October. Timing of harvest for canola is critical, particularly when direct cutting. When it is ready, it is imperative to have machinery ready to go to avoid potential loss to shattering or other factors. Canola is ready to harvest when the majority of pods from the top to the bottom of the plants can be easily hand threshed and seeds are brown to black in color.
Canola is most commonly swathed or direct cut. The choice of method is often driven by time, weather, and personal preference. Swathing is more common in Montana, in Washington for irrigated winter canola, and in the Willamette Valley of Oregon. The ideal time for swathing is at 1/3 brown seed (the lower third of the pod canopy has brown seed. Another method of harvest used in some areas is pushing, which is similar to swathing but crimps rather than cuts the stalks.
Canola settings are listed in most combine manuals, and those can be used for a starting point. One of the most important aspects of harvesting canola is that harvest speed is slower that with small grains, particularly in dense stands or when stalks are thick. Adjustments will likely be needed depending on moisture, slope, and even variety.
Pod sealant: The use of pod sealant to protect against seed shatter close to maturity has had mixed results according to several growers surveyed in the PNW. Some growers always apply it, others only occasionally. Canola varieties are becoming more shatter resistant, and pod sealant protects against wind, rain, and hail for varieties that not shatter-resistant. If you opt to apply pod sealant, be sure it is ordered far in advance of harvest so it is ready and waiting at the airplane hangar. It should be applied when the lime green pod color phase is ending and pods are starting to turn yellow but not yet splitting. The cost for product is ~$8-10/acre, plus the cost of a plant (~$7-9/acre).
- Harvesting canola (pdf – presentation by WA grower)
- Video library – Harvesting & Storage
- Photo gallery – Harvest
- The WSU-WOCS project has a harvest loss pan available at the Pullman campus for growers that would like to borrow it. Contact Ron Sloot to make arrangements to borrow it.
- Combine Optimization Tool (Canola Council of Canada)
“Canola is not always more valuable than wheat until you look at the whole picture.” – Wade Troutman, Bridgeport, WA