- What is Canola?
- How does Canola grow?
- What plant family is Canola?
- How did Canola get its name?
- Where did Canola come from?
- Is Canola Rapeseed?
- How much is the Canola Industry worth in Canada?
- Who grows Canola?
- What do the Canola Growers do?
- Is Canola Oil safe?
- Why should I buy and use Canola Oil?
- Growing Canola
- Canola in crop rotation
- Financial aspects
- Organisations and contacts
- The Bulletin
- Winter Canola Harvest
- Harvesting Canola
- Reduce Shatter Loass by Combining:
- Winter Canola – Swathing Setup
- Winter Canola Harvest- Time of Swathing Guide
- Tips on Combining
- Combine Tips to Reduce Harvest Loss
- What Cover Crops Should You Plant?
- Single vs. Mixes
- Make it Easy
- So do cover crop mixes ding yields?
- Brassica cover cropping for weed management: A review
What is Canola?
Canola is a crop with plants from three to five feet tall that produce pods from which seeds are harvested and crushed to create canola oil and meal. These plants also produce small, yellow flowers, which beautify the environment.
Canola seeds contain about 45 percent oil. This large percentage of oil comes in a small package; canola seeds are similar in size to poppy seeds, though brownish-black in color.
Although they look similar, canola and rapeseed plants and oils are very different. Canadian scientists used traditional plant breeding in the 1960s to practically eliminate two undesirable components of rapeseed — erucic acid from oil and glucosinolates from meal — to create “canola,” a contraction of “Canadian” and “ola.” Canola oil is prized for its heart-healthy properties with the least saturated fat of all common culinary oils.
Canola belongs to the Brassica plant family as does mustard, broccoli, Brussels sprouts and cauliflower. Besides the United States, canola is grown in Canada and Australia as well as in Europe and China (but the crop is called “double low rapeseed,” referring to its low levels of erucic acid and glucosinolates, in the latter two countries). In America, the ratio of supply versus demand of canola oil is about 1:4, which presents a huge opportunity for U.S. producers to grow more canola. The healthy oil from this crop is consumed all over the world and number three by volume among edible oils.
About 2 million acres of canola are currently grown in the United States, predominantly in North Dakota, but also in Minnesota, Oklahoma, Kansas, Texas, Montana, Idaho, Oregon, Washington, Kentucky and several other states.
Canola is a plant that is a member of a large family of plants called crucifers. Crucifers are easy to identify because the four yellow flower petals form the shape of a cross.
How does Canola grow?
Canola plants grow to a height of one to two metres. The yellow flower produces seed pods that are about 5 centimetres in length. There is an average of 60 to 100 pods per plant. Each seed pod contains 20 to 30 tiny, round seeds which are 1 mm. in diameter. When it is ready to harvest, the plant changes colour from green to light yellow. These tiny seeds are crushed to extrude canola oil. From germination to seed production, the life cycle of a canola plant takes about 3 1/2 months, depending on temperature, moisture, sunlight and soil fertility. Canola is a cool season crop. It grows particularly well on the prairies, where cool nights and hot days allow it to develop its unique fatty acid profile.
What plant family is Canola?
Canola belongs to a section (or genus) of the crucifer family called Brassica. As well as canola, Brassica plants include mustard, Brussels sprouts, cabbage, cauliflower, broccoli and turnip. Brassicas are a major source of food in many countries, including Canada.
How did Canola get its name?
The name ‘Canola’ was registered as a trademark in Canada in 1970. The name comes from “Can” as in Canada and “ola” as in oil!
Where did Canola come from?
The plant was bred by Canadian scientists, Dr. Baldur Stefansson and Dr. Keith Downey, who selected rapeseed populations when looking for a crop that would produce a healthy, edible oil product. Prior to canola oil, most of the oil Canadians used for food purposes was imported and people wanted a home-grown edible oil. Canola was selected from rapeseed through the knowledge and ingenuity of these prairie plant scientists.
Is Canola Rapeseed?
Canola is NOT rapeseed. It may look the same but it’s nutritional makeup is totally different. Canola came about only after years of hard work, research and countless field tests of new plant varieties.
How much is the Canola Industry worth in Canada?
Canada’s canola industry adds $13.8 billion in economic activity to the Canadian economy. The canola industry creates over 216,000 jobs in western and eastern Canada in production, transportation, crushing, refining, food development, manufacturing and service.
Who grows Canola?
More than 43,000 Canadian farmers grow canola, largely as full-time farmers and in family farm businesses. They depend on canola to generate between one third and one half of their revenues. Ninety per cent (90%) of Canadian canola is exported throughout the world, bringing back more than $9 billion to the country’s economy.
How do the Canola Growers fit into all of this?
The Canola Growers are a non-profit organization that represents the canola farmers. Farmers pay a check-off at the elevator when they deliver their canola for sale.
What do the Canola Growers do?
We are committed in providing health and recipe information on canola oil to consumers, health professionals, dietitians, educators, chefs and food service personnel. We are also highly committed to our growers and run many programs to ensure that they have access to the best resources they need to grow a safe, sustainable, healthy crop for the world.
Is Canola Oil safe?
Yes, you can be assured that canola oil is safe. Canola oil meets strict quality standards determined by industry and government regulatory agencies. Consumers can therefore be assured that the canola oil they purchase is of the highest quality.
Why should I buy and use Canola Oil?
Canola oil is your local choice for oil. Grown right here in Canada! Canola oil is the best blend of fats for good health. Canola oil is low in saturated fat and contains zero trans fat and cholesterol. Canola oil is a source of omega-6 which is important for the brain and essential for the growth and development of infants. Canola oil is also high in omega-3 fat which helps to protect against heart attacks and strokes. Canola oil is high in monounsaturated fats, which reduce the risk of coronary heart disease. You can also visit our blog post When can I use canola oil for a more informaiton.
In some drought years when crops are very short, and with some of the newer, more shatter-tolerant varieties suited to low rainfall areas, canola may be harvested without windrowing (direct headed).
Australia usually produces between 2 to 3 million tonnes of oilseed crops each year, with canola and cottonseed accounting for over 90 per cent of total oilseed production, with soybeans and sunflower comprising a further 3 and 4 per cent respectively. Canola production is now the largest oilseed crop representing well over over half of Australian oilseed production over the past 5 years, while cottonseed comprises around a third.
There are also small quantities of minor oilseeds such as safflower and linseed grown in Australia.
In Victoria the main production area is the south west but the crop is important across the grain belt. The release of earlier maturing cultivars has extended canola’s range into the Mallee.
The area sown to canola depends on demand and prices in relation to other crop choices and factors such as the timing of the autumn break and the amount of moisture stored in the subsoil in low and medium rainfall zones.
The rank order of production by States is Western Australia, NSW, Victoria and South Australia.
While Australia is a relatively small producer of oilseeds by international standards, it is widely regarded for its high quality exports and has developed some significant international markets for its canola and cottonseed exports. Currently, the UE, Japan, Pakistan and Bangladesh are important markets for Australian canola.
A crop of canola at flowering in the
west Wimmera (Photo courtesy,
The marketing of canola is well organised. A number of buying organisations offer farmers the option of taking fixed price contracts during the season. The farmer nominates the tonnage which they will deliver for each contract written. Alternatively, a farmer can choose not to make an early decision and instead sell after harvest, perhaps warehousing the seed while deciding how long to wait and who to sell to. There are minor variations on these options.
Canola in crop rotation
Canola is an excellent choice to enhance or extend a crop rotation. It produces a high yield and can be a profitable crop in its own right as well as an excellent fit with cereals or pulses. The average yield of canola across Victoria between 2002 and 2007 was 1.3 t/ha, which includes three drought years. Yields of more than 4 t/ha are achieved by some farmers in better years, especially in higher rainfall regions such as south west Victoria and sometimes under irrigation. Cereal yields after canola are often enhanced because of the disease cleaning that occurs when an unrelated crop type such as canola is alternated with cereals and kept free of grassy weeds.
Canola in the rotation allows farmers to better manage their weeds. Because canola is a broadleaf crop, and because there are different herbicide tolerant varieties of canola, farmers have more options for weed control than in cereal crops such as wheat and barley.
A realistic target yield can be determined by calculating potential yields based on the amount of growing season rainfall expected, subsoil moisture available to the crop at sowing time and the sowing date. The target yield is 85% of the calculated potential yield. For example, a canola crop sown in mid May in a location which received 285 mm average growing season rainfall, with no stored subsoil moisture, can expect a potential yield of 2.66 t/ha. The target yield is 2.5 t/ha. In recent years, below average rainfall has meant that some farmers have become better prepared for dry seasons and have tried, where possible, to reduce costs of crop sowing inputs. They spend more on the crop at later growth stages when they have a better idea of how the season is progressing. Nitrogen fertiliser is the single biggest cost to canola growers. By applying most of the nitrogen fertiliser later in the season, but before stem elongation, rather than all before sowing, farmers can reduce some of the financial risk of growing canola.
The crop has higher direct costs than cereal (about $350-400 per hectare compared to about $200-300 per hectare) but price per tonne is also higher (about $500 per tonne compared to $270 per tonne delivered port).
The five year average price for canola, in 2011, is approaching $500/tonne with high prices in the face of a worldwide shortage of oilseeds for food production and low canola production in eastern Australia due to drought.
For 2012, a one and a half tonne per hectare canola crop is estimated to return a gross margin of $350-400. These figures contain challengeable assumptions as grain prices vary during the year, different farmers have different costs and yield can vary. Also, the yield benefit of break crops like canola to subsequent cereal crops is not factored into the break crops gross margin.
Organisations and contacts
Australian Oilseeds Federation
PO Box H236
Australia Square, NSW 1215
Phone: (02) 8007 7553
See DEPI’s Victorian Winter Crop Summary for the latest varieties and yields.
This Agnote was developed June 2000.
May 2009 by Felicity Pritchard, Oilseeds Industry Development Officer (Pritchard Agricultural Consulting and Extension) and Chris Bluett, DEPI Ballarat.
December 2010 by Steve Holden, DEPI Hamilton.
Published and Authorised by:
Department of Environment and Primary Industries
1 Spring Street
This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968.
The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication
OKLAHOMA CITY – You’ve driven past it; you might have even stopped to take a picture in it.
The fields of yellow flowers are a pretty sight all around Oklahoma.
It’s that bright yellow that catches your eye but do you actually know what it is?
The plants that seem to be the perfect background for candid snapshot is canola.
It’s not just a pretty flower, Canola helps farmers all across the state grow a stronger wheat crop.
Ray Ridlen, extension educator at OSU, explains how it all started.
“We were getting lots of grassy weeds in our wheat and wheat is a grass,” he said.
Those weeds started taking over fields because they grew resistant to herbicides.
Farmers needed a way to kill the weeds but not their crops.
They started planting canola instead of wheat for a year or two and were able to use different, stronger poisons to clean up their fields.
“Same time frame as our winter wheat,” Ridlen said. “We plant it in the fall, harvest in the spring like we do our winter wheat. So it matched up really good.”
The demand for canola oil is very high, so farmers aren’t losing money when they take a break from wheat.
Canola has only been grown in Oklahoma for about seven years.
It’s a new experience for a lot of farmers and they can’t wait to get back to the grains.
“They’re making money on it,” Ridlen said. “But it’s a little out of the comfort zone of a lot of our wheat producers.”
Canola stands for “Canadian Oil Company” they developed the crop in the 1970s.
The springtime color scheme provided by winter annual weed species in many no-till fields has shifted from the hearty purple of flowering henbit and purple deadnettle to the bright yellow flowers of two species. Yellow rocket and cressleaf groundsel (a.k.a. butterweed) both produce bright yellow flowers and are common across much of the southern half of Illinois. Although flower color is similar, the plants are distinct species. Most of the yellow-flowered plants currently in fields is butterweed.
Native to the United States, butterweed (Packera glabella) can be found from Texas east to Florida, northward along the Atlantic coast to Virginia, and west to Nebraska. Herbarium specimens from the Illinois Natural History Survey indicate that butterweed specimens were collected in Illinois as early as 1932. The earliest herbarium specimens of butterweed generally originated from counties in southern Illinois. During the 1980s and 90s, the Illinois Natural History Survey augmented their collection with specimens from more northern counties, such as Champaign and Vermillion. While scouting fields in Kankakee County recently, butterweed was easy to find. Typically favoring moist to saturated soils, butterweed thrives in areas such as wastelands, pastures, fence-rows, and roadsides. With the increased adoption of no-till and reduced tillage conservation practices, butterweed has become more prevalent in areas devoted to agronomic crop production.
Butterweed completes its life cycle within one year (an annual growth habit). Field research was conducted from fall 2004 through spring 2006 at the University of Illinois to determine the emergence timing and growth characteristics of butterweed in no-till fields. Butterweed emergence was predominately during the fall months and was essentially completed by November, although some emergence occurred in the spring. From these results, we generally consider butterweed to be a winter annual species.
Following emergence, the formation of rosettes occurs prior to overwintering. The rosette leaves have petioles that connect the leaves to the stem. Often the under side of the rosette leaves are deep purple. Bolting (stem elongation), flowering and seed production occurs the following spring, often during late April to early May. The stem of butterweed is glaborous and hollow. After bolting, petioles are absent from leaves on the upper part of the plant. The leaves are pubescent, generally irregular in shape, and are deeply cut to the midrib. The elongated stem often has a purplish tint. A member of the Asteraceae family, butterweed produces two types of composite flowers. The outside portion of the flower contains ray florets while the center part contains disk florets. The flowers are bright yellow and grouped in clusters that are located on several flowering stalks of the plant. Seeds are easily disseminated via wind due to the white hairs (pappus) on the apex of the achene.
Yellow rocket (Barbarea vulgaris) is a winter annual species in the mustard (Brassicaceae) plant family. The plant can produce numerous stems that grow from a basal crown surrounded by a rosette of deeply green leaves. These basal leaves range in length from approximately 2–8 inches and have a large terminal lobe that is somewhat heart-shaped at its base. Stem leaves are arranged alternately and become progressively shorter toward the top of the plant. Flowers are produced on spike-like racemes and consist of four petals that form a cross. Seed pods (siliques) are about 1 inch long and nearly square in cross section.
(Courtesy of Canola Council of Canada)
Canola Swathing – Seed Color Change – Video
(Courtesy of Canola Council of Canada)
Why is desccated canola not drying down? (Reglone PDF file Harvest Aid)
Winter Canola Harvest
- Canola is an indeterminate crop and has a certain amount of immature seeds at harvest.
- Canola is ripe when the pods are dry and rattle when shaken.
- Seed is dark brown to black in color at maturity. Stems will still be partly green.
- Harvest at 8 to 10% moisture. Dryers? 11 to 13%.
- Canola should be cut just below seed pods.
- Straight combining will perform better in heavy canola where it is leaning, with pods “laced” together.
- Canola that is ready should be harvested immediately.
- Swathing is possible alternative for harvesting winter canola.
- Proper Harvest Moisture: 9-10%, canola will store well at this moisture.
- Combine Settings: Follow manual for rapeseed (John Deere.com).
- Slow cylinder speed slow as possible (450-550RPM).
- Open concave 3/4 of the way. 1 to 1 1/2′ clearance on concave settings.
- Fan speeds set at 2/3 of small grain settings (750-850RPM).
- Rotor Speed 350-650, Concave indicator 10-20, Fan Speed at 700 RPM
- Match reel speed with ground speed. Set fingers straight up and down to minimize wrapping.
- Proper speed: A slower speed will be needed compared to small grain.
- Duct Tape!!!!!!! Very Important .
Axial-Flow Combine (Case 2388)
Reduce Shatter Loass by Combining:
- A ripe crop at higher seed moisture levels and drying the seed.
- In the cooler part of the day.
- At night when pods are damp from dew.
- At night during periods of very hot weather.
- Average seed losses in the field can range from 0.2 to 1 Bu/A.
- Canola can be harvested when too damp to harvest wheat.
However, seed moisture levels must be continuously monitored to ensure they do not exceed safe storage levels.
Winter Canola – Swathing Setup
- It is critical that the plant be at the proper stage of maturity.
- Plants should be swathed when 60 to 75% of the seeds are black and contain 30 to 40% moisture.
- The swath is placed on stubble for approx. 7 to 10 days or until the seed moisture is 8 to 10%, when the crop should be combined.
- Research has shown a possible yield reduction of 10% can occur when swathed at the optimum stage compared to direct combining.
- Typically canola producers can swath and pick up canola before wheat is ready to harvest.
- Under moderate windy conditions there is less shatter loss when canola is in a windrow compared to ripe canola left standing.
Winter Canola Harvest- Time of Swathing Guide
- Start inspecting field approximately 7 to 10 days after flowering ends.
- Walk out and sample 5 to 10 plants. Most of the seeds in the top pods will be firm, and roll, as opposed to break or crush, when pressed between the forefinger and thumb.
- Using the seed color change chart take note on the percentage of the plants. Examine only pods on the main stem. Seeds in pods on the bottom third of the main stem mature first. Only seeds with small patches of color (spotting) should be counted as color change.
- After assessing the main stem, look at the seed from the pods on the side branches to ensure that they are firm with no translucency, especially with low plant populations.
- Once sampled average out the percent seed color change for that filed.
- Continue inspections every 3 to 4 days to monitor color change in the first formed pods on the bottom of the main stem.
- Key to curing crop is moisture. The enzyme responsible for clearing the chlorophyll requires moisture. Curing will take approx. 14 days.
- Best time to swath is when all the seeds contain about 30 to 35% moisture. The color of the seed is a good indicator of seed moisture content.
- At the proper moisture about 30 to 40% of the seeds in the pods on the main stem will have changed color or have started to change color.
- When conditions are hot and dry, swathing is not recommended. Swathing during the cool evening hours, at night, or early morning will allow the plant to dry down at a slower rate. Lowering the chance of green seed and poor oil content.
Tips on Combining
- Combine table should be set low when first starting out.
- Leave reel positioned up and away from the table to prevent shattering
- As crop begins flowing into the combine, begin to raise the table and lower the reel.
- Don’t use too much reel on the crop.
Combine Tips to Reduce Harvest Loss
- First, set your combine by the book
- Then you may need to:
- Slow down the cylinder
- Adjust the concaves
- Close the sieves
- Reduce the air
- Raise the reel
- Put reel directly over sickle
- Match Reel speed with ground speed
- Cut just below the pods
- Slow down at first, then see how much you can speed up
- Check for leakage on your trucks/combines
- Aim for 2.0% dockage or less
- Tarp your trucks
Pushing is a relatively new procedure for canola harvesting that has been suggested as a faster and less expensive alternative to swathing. A pusher is mounted on the 3 point hitch of a bi-directional tractor and it is driven through the canola at a relatively high speed to force it to lodge. Mounting a pusher on front loader brackets has not been successful because the unit is too wide and too heavy and must be kept level during relatively high speed operation. The idea is that by pushing the canola over it is less susceptible to blowing in the wind, which causes shattering. Although our experience with pushing is very limited, it appears that it may work better in some crop situations than in others. Tall even crop growth works better with pushing. Shorter and thin crops simply stand back up, minus a few pods, after the pusher has gone over them. The optimum speed for pushing may vary depending on crop size and density. The idea is to push the stalks over, but not break them off or rip them out of the ground. Vertical sickles at both ends and directly in front of the tractor tire tracks are designed to insure a clean cut between passes and reduce the amount of canola crushed to the ground by the tire tracks. Pods cut off by these sickles are likely to be lost onto the ground. After the crop matures it is combined with a typical header. The combine must travel in the exact opposite direction of the pusher. The combine header also has to operate much closer to the ground than for standing canola. Combining is slower, because of the additional stalk material that enters the combine. Pushers may work best in fields with high production potential and few or no terraces. Growers should carefully scout their fields for armyworms and other foliage feeders and if they are present control them before pushing, or forcibly lodging their canola. A few growers in Oklahoma plan to try pushing their canola in 2009.
What Cover Crops Should You Plant?
Three cover crop categories exist: Grasses like cereal rye and Sudan grass; brassicas like turnips, radishes, and rapeseed; and legumes like hairy vetch and clover.
So which ones are for you?
It depends on a farmer’s goals. All cover crops significantly reduced nitrate-N accumulations in Iowa State University (ISU) trials. Cereal rye and oats reduced nitrate-N levels the most, but mixes worked well, too, says Mark Licht, an ISU Extension agronomist.
Radishes are a great gateway cover crop. However, they can winter-kill in colder areas like Iowa and more northern states, says Emily Waring, an ISU graduate research assistant. Winterkill also nabs oats and rapeseed, she says.
“Grasses are more resilient to cold weather,” she says. “Cereal rye was the only crop to consistently survive over the winter in our trials.”
Single vs. Mixes
Single-species cover crop seed is less expensive than cover crop mixes. Per-acre seed costs from a 2013-2017 ISU trial are listed below. Good news for farmers: Quantity discounts and other factors often make seed costs lower than those recorded by ISU.
- Cereal rye: $18.78
- Oats: $17.44
- Rye/rapeseed/radish: $30.46
- Oats/hairy vetch/radish: $63.29
Make it Easy
Spending $10 to $12 per acre for cereal rye cover crop seed is Allie Marks-Slykerman’s goal.
“I like cereal rye as a gateway cover crop because it is easy,” says the LaMoure, North Dakota-based Centrol crop consultant. “Once you add things like clovers and legumes, it gets more expensive.
“I want to stick to things I know I can terminate. After you get it down, then you can talk about things like faba beans or kale,” she says.
So do cover crop mixes ding yields?
If terminated on a timely basis, no.
That’s what ISU researchers found. They compared corn and soybean yields in fields planted to single-species and mixed- species cover crops to fields with no cover crops.
Brassica cover cropping for weed management: A review
Cover crops offer many benefits for farmers seeking to reduce their reliance on external inputs. These include maintaining and improving soil quality, preventing erosion and, in some cases, allelopathic weed control. Allelopathic potential has been well documented for cover crops such as cereal rye (Secale cereale L.), hairy vetch (Vicia villosa Roth) and red clover (Trifolium pratense L.). Much less is known about other potentially allelopathic cover crops, including certain brassicaceous species that are normally grown for their oilseeds, including canola and rapeseed (both Brassica napus L.) and mustards (e.g., Sinapis alba L., white and yellow mustard). Because of their potential contribution to pest management, there is increased interest in growing brassicas, both as cover crops and as seed crops harvested for oil production. In this review, we first discuss unique attributes of brassicas that make them promising options for pest management, as well as generally beneficial cover crops. Next, we review the literature from controlled settings on the effects of brassicas, brassica extracts and isolated compounds contained therein on seed germination, seedling emergence and establishment, and seedling growth—effects that, combined or taken alone, could contribute to reducing the density and vigor of weed communities in the field. Field studies examining the detrimental effects of brassicas in rotation with other crops, as well as examining the effects of brassica cover crops on weed dynamics in subsequent crops, also are reviewed. Finally, we review some important agronomic considerations about the use of brassica cover crops.
The other brassica are fairly similar to radishes but with less root volume. Turnips will have more tuber-like growth at the soil surface and are better suited to late summer and fall grazing. Turnips may over-winter and do not produce the odors of radish upon decomposition. Rapeseed, also known as canola, has typically been grown as an oil crop but has grown in popularity as a cover crop in recent years.
Radishes, and other brassicas, release bio-toxic metabolites upon decomposition in soil, which have shown modest suppressive effects on certain weed, insect and parasitic nematode pests. These chemical compounds include glucosinolate and biologically active sulfur containing thiocyanates, which are also associated with the sulfurous odor given off by radishes during decomposition. Radishes have been shown to be good scavengers of residual soil nitrate. Radish will produce seed, causing a weed concern, if planted too early in the season (July). Radishes are fast growing with competitive, leafy top growth. Mixes must consider compatible species and modest radish seeding rates. Radish and radish mixtures require 40 to 60 lbs N from fertilizer, manure or legume credits.
It is not recommended to seed brassicas alone due to erosion concerns so these are recommendations for mixes. The following are radish seeding recommendation, rapeseed should planted at seeding rates similar to radish, turnips should be about half (2-4 lbs. per acre in a mix).
- Radish, 5 to 8 lbs per-acre + 30 lbs per-acre oats or spring barley.
- Radish, 5 to 8 lbs per-acre + 35 lbs field peas + 30 lbs per-acre oats or spring barley
- Radish, 5 lbs per-acre + 8 lbs berseem clover + 10 lbs annual ryegrass
Seeding depth: Drill 1/2″
Fertility needs: 40-60lbs of N
Management and termination
None needed for turnips, will winterkill in Wisconsin.
Rapeseed may overwinter and need spring termination. Termination may require at least one quart/acre of glyphosate and/or multiple applications.
In a cover crop mix:
Brassicas are only recommended in mixes, seed seeding rates above.
Research in Wisconsin:
Research updates coming