Canola

24.05.17

A minor crop in the late 1980s, canola is now Australia’s third largest broadacre crop (behind wheat and barley) and the major broadleaf rotation crop in the grain-producing regions of Australia. Easily recognised by its vivid yellow flowers in spring, it is grown for the oil extracted from its seed, which is used in margarine, cooking and salad oils, and edible oil blends. Canola oil is considered healthy because it is low in saturated fat, high in monounsaturated fat, has an ideal balance of omega fatty acids and is a good source of vitamin E.

A nutritious stockfeed is also produced from the residue (meal) remaining after the oil has been extracted, and is incorporated widely in rations for pigs, poultry and dairy cattle.

Overview

Canola belongs to the botanical family Brassicaceae, which also includes mustard, turnip, wild radish, cauliflower, cabbage and broccoli. Canola was developed from rapeseed in Canada to produce an oilseed crop with an improved nutritional composition, and until 1979 was known as rapeseed. There are two genetically modified (GM) traits that confer herbicide tolerance that have been bred into many varieties to provide the tolerance benefits over a wide range of agronomic characteristics and production situations. The GM varieties of canola have been approved for production in Australia, however not all states permit them to be grown.

A record four million tonnes of canola was harvested in Australia in 2012–13, with a value of AU$2.2 billion. Australia consistently exports more than two million tonnes of canola seed per annum, making it the world’s second largest exporter. Canola is considered a relatively easy crop to grow, however it does require more management, monitoring and inputs than cereal crops.

It is generally grown as a broadacre crop on large agricultural enterprises (several hundred or thousands of hectares) and farmers who grow other grain crops generally have most of the equipment needed to grow canola. Although, it may be necessary to pay a contractor to swathe (or windrow) the crop to protect the pods from shattering and losing seed. It is grown in rotation with winter and summer crops (cereals, oilseeds and grain legumes) depending on climate and availability of water. It can be a profitable crop in its own right and is a valuable break crop between cereals. A wheat crop grown after canola often yields about 0.8 t/ha more than wheat grown after wheat.

Growers are represented by the local farming systems groups, state farming bodies, and the Australian Oilseeds Federation.

Facts and figures

  • Canola is Australia’s third largest broadacre crop and is grown on large agricultural enterprises
  • It is grown for its seed, which is crushed for oil that is used in margarine, cooking oils and edible blends
  • Canola oil is considered a healthy choice because it is low in saturated fat
  • It provides an environmental benefit to farmers looking for a break crop to grow in rotation with wheat
  • Canola requires more management and monitoring than cereal crops
  • Most of the equipment needed to grow canola is already available on most properties that grow other crops

Production status

The 2012–13 Australian canola harvest was the largest on record at 4,000,000 tonnes, up 17% on the previous record set in 2011–12. Annual production averages 3.5 million tonnes, with Western Australia the largest producer, followed by New South Wales, Victoria and South Australia.

Australia exports over two million tonnes of canola per annum to its main export markets of Japan, China, Pakistan, Europe and Bangladesh.

 - image

Map of current and potential growing regions

Uses

Canola is an oilseed crop, with its seeds yielding high quality oil for use in most domestic and commercial applications where vegetable oils are used including margarines, cooking oils and salad dressings. Several fast food enterprises now also use canola oil.

The oil is considered healthy because it is low in saturated fat, high in monounsaturated fat, has a desirable level of omega fatty acid and is a good source of vitamin E. More recently, high oleic canola has been developed, with higher levels of monounsaturated fat, and lower levels of omega 3 fatty acid, making it ideally suited for commercial deep frying applications.

Canola oil can also be used as a biofuel and several farming businesses have on-farm oil production systems to provide a fuel source for their operations. In recent years much of the seed that has been exported to Europe has been used for biodiesel feedstock.

Canola meal is the by-product of the oil extraction and is used as a nutritious input in animal feeds for the pig, poultry and dairy industries. The meal can also be used as an organic fertiliser.

Production Requirements

Growing regions

Canola can be grown in most areas where broadacre cropping is possible, particularly in the traditional wheat–sheep belt and mixed farming regions of Western Australia, South Australia, Victoria, New South Wales, southern Queensland and Tasmania.

Soil type

The wide distribution across Australia indicates its suitability to a wide range of soil types. It is sensitive to waterlogging, however it grows well on soil textures from sandy soils through to clay soils, so long as the soil is well-drained.

While canola is relatively tolerant of acidic soil, yield will be affected when the acidity has resulted in manganese and aluminium toxicity. Liming before sowing the crop will alleviate the toxicities, as well as improve soil chemistry for other crops in the rotation.

It grows best on fertile soils and it is generally accepted that the best wheat growing soils will produce the best canola crops. Soils of uniform type and characteristics will allow for a more even sowing depth, seedling emergence and crop ripening.

Canola has higher sulphur requirement than other broadacre crops, and the nutrient may be applied as fertiliser or by gypsum. Gypsum will also improve soil structure, and improve dispersive and sodic soils that are prone to surface crusting, which can significantly reduce emergence of canola seedlings.

More information on climate and soils is available from the Australian Oilseeds Federation.

Climate

Canola fits well into the temperate climate zone, traditionally in a crop rotation on grain–sheep farms in the 450–700mm annual rainfall zones but newer varieties and farming practices allow canola to be grown in much drier environments, in areas where rainfall is down to about 325mm annually.

It is also suited to the subtropical zones of northern New South Wales and southern Queensland, however adequate winter rainfall is required for good crop growth.

Varieties

All canola grown commercially in Australia is the swede rape type Brassica napus. There are also small quantities of Brassica juncea (brown or Indian mustard) grown in Australia.

The selection of a variety will depend on maturity, herbicide tolerance, blackleg resistance, relative yield, oil content and early vigour, as well as regional suitability. It is recommended that new entrants to the industry seek advice from an advisor or agronomist on the best variety for their circumstance.

Varieties include conventional ones and those that have been traditionally bred with a range of attributes that provide benefit to the grower and end-user, including herbicide resistance (triazine tolerance and Clearfield varieties), high yielding hybrids and varieties with an oil composition suited to the fast food industry.

There are genetically modified (GM) varieties that contain traits that confer additional herbicide tolerance. The GM varieties of canola have been approved for production in Australia, however not all states permit them to be grown. Information about the approved GM canola and the states in which it can and cannot be grown are contained in a fact sheet prepared by the Office of the Gene Technology Regulator.

The National Variety Trials (NVT) is an independent source of advice on the performance of available varieties.

Planting and crop management

Canola is relatively easy to grow but it does require higher levels of monitoring, management and inputs than cereal crops.

Paddock selection must take into account the risks associated with the disease, blackleg. It is advised that canola be grown in a paddock where it has not been grown for at least four years and where it is well separated from paddocks where it was grown recently. Paddocks that have had triazine herbicides (including atrazine and simazine) applied in the previous year should also be avoided as residues can affect the seed’s germination. All plantback periods for previously used herbicides should be noted before sowing.

Canola is generally planted during early April and mid May, but may be extended to June in high rainfall areas. It is a tiny seed and sowing depth must be well controlled. It is best sown shallow and evenly, in soil with good moisture and covered by a thin layer of soil to protect it from drying out before or after germination.

Nutritional requirements will vary depending on soil type, rainfall, rotation and target yield, however it will require applications of nitrogen, phosphorus and sulphur to reach good yields at maturity. Fertiliser application should be based on a soil test and yield target. For new producers, an agronomist or advisor should be consulted.

Canola is also an important crop in irrigation areas, and when watered strategically and carefully, good yields can be achieved. Raised beds are ideal for irrigated crops, especially where the slope is 1:1500 or flatter. However, crops are grown successfully in border check bays, under spray irrigation and on terraced contours (bankless channels).

Critical irrigation times are at stem elongations and flowering. Poor irrigation layouts may result in transient waterlogging in some cases with reduced grain yields. Good advice on irrigation practices is provided in Canola: Best practice management for south-eastern Australia.

The use of canola as a break crop in a rotation with wheat has environmental and economic benefits. Canola is a valuable crop in itself but it also makes a contribution to the extra profitability of the following cereal crop by breaking the disease cycle and by acting as a biofumigant. The root system of the subsequent wheat crop is healthier and larger, and able to use more nitrogen and moisture from the soil.

Weeds, pests, and diseases

Early weed control must be effective, but once established, canola is effective at crowding out weeds. There are a large number of weeds that can affect production either through direct competition for nutrients or possibly as hosts for diseases such as sclerotinia. A range of herbicides and management practices are available for use by growers and the Grains Research and Development Corporation (GRDC) has developed information about integrated weed management.

Growers should be aware of the following four important Brassica weeds when selecting a paddock for canola, as these may only be controlled by particular herbicide groups that will determine what canola varieties can be grown. Further, seed of these weeds will contaminate the final harvest of canola. The weeds are:

  • charlock (Sinapis arvensis)
  • wild radish (Raphanus raphanistrum)
  • wild or Mediterranean turnip (Brassica tournefortii)
  • wild cabbage or hare’s ear (Conringa orientalis).

Canola crops are most susceptible to damage by earth mites, lucerne flea and false wireworms during crop establishment, and to a lesser extent by aphids, native budworm and Rutherglen bug during flowering and podding. SARDI has a fact sheet on the pests of canola and the Australian Oilseeds Federation also provides a description of these pests and their management options.

Blackleg, caused by the fungus Leptosphaeria maculans is the most serious disease of canola in Australia. In the autumn and winter, rainfall triggers spore release from the stubble and lesions develop on the plant. Once a lesion has formed, the fungus grows within the plant causing stem infection, resulting in a canker. Severe canker will sever the roots from the stem while a less severe infection will restrict water and nutrient flow within the plant. However blackleg can be successfully managed through a range of strategies including varietal selection for resistance (Blackleg ratings are published each year), rotational cropping (and avoiding the previous year’s canola stubble) and fungicide use, if necessary.

GRDC has developed a Blackleg Management Guide, which outline how to manage the disease but it is important to review and monitor blackleg management strategies on a regular basis.

In 2013, sclerotinia stem rot affected significant areas of the southern cropping region. Frequent rainfall and mild temperatures during the flowering period triggered spore production. These factors, combined with the increasing intensity of canola in cropping rotations and the low levels of inoculum build up in the soil meant the conditions were favourable to the disease. A number of management strategies may be able to be introduced to prevent and manage the disease including using only clean seed, correct paddock selection, regular crop rotation, following recommended planting dates and the use of fungicides, if necessary. However, it is difficult to predict the likely development of sclerotinia and more research is needed to allow growers to predict the likely incidence from year to year. More information about managing sclerotinia stem rot in canola is available in the Sclerotinia fact sheet developed by the GRDC.

The Canola Association of Australia has also collated a number of other resources related to the management of pests and diseases.

Infrastructure Requirements

Large scale agricultural machinery, including tractors with air seeder/disc drill attachments, boom sprayers, windrowing attachments, combine harvesters (headers) with specialist attachments for canola harvest, chaser bins and grain trucks, will be required for growing a successful canola crop but most of these are available on farms that grow other crops.

If grain is to be stored on farm, ideal storage is a well-designed cone-based silo that can be fully sealed for insect control and equipped with well-controlled aeration to maintain grain quality.

Harvesting & Processing

Canola is ready to harvest when pods are dry and rattle when shaken. At this stage the pods are pale brown and the seeds are dark brown to black. At harvest, the seed moisture content should be 8% or lower.

There are two main methods of approaching a harvest: windrowing and then harvesting, and direct heading.
Windrowing (or swathing) is the practice of cutting/mowing the crop to allow even senescence and ensure the grain is dry for harvest. Most growers in Australia would windrow their crops, and the operation can be carried out with tractor drawn or self-propelled windrowers, or with a modified front on a harvester.

Windrowing has been popular in Australia because it results in uniform ripening, earlier harvesting, less exposure to spring storms, hail and wind and is believed to reduce shattering losses during harvest. The canola is harvested, using a conventional harvester, between 5 and 14 days after windrowing.

Direct heading involves harvesting the standing crop with either an open-front with an extended platform or with a belt-front attachment.

Direct heading is gaining popularity as it is cheaper than windrowing and evidence is mounting that if undertaken properly, the losses and yield are comparable between the two methods. However, there is no flexibility in harvest timing if using the direct heading method as the canola must be harvested when it is ready, creating periods of intense harvest activity, particularly when coinciding with the harvesting of other crops.

The harvest method chosen often depends on the availability and cost of contract windrowing, the type of harvesters available and the risk of bad weather. The Australian Oilseeds Federation has produced a Harvest Management booklet that outlines harvest processes in detail.

Harvested grain is delivered directly to the buyer or it may be stored on-farm until sale.

Approximately 43% of a canola seed is oil. The oil is made at a processing facility by heating and then crushing the seed, the oil is then refined. What remains is the meal that is used as high quality animal feed.

Markets & Marketing

Canola oil is a key ingredient in many foods. Its reputation as a healthy oil has created high demand in markets around the world. Australia has a reputation for high quality oil and is currently exported to Europe, Japan, Pakistan and Bangladesh. Canada is Australia’s main competitor in world markets.

The marketing of canola in Australia is well established and there are a number of grain marketers offering contracts to growers.

Growers have a number of options when choosing to sell their canola. They can forward contract the crop to a marketer, accept the best cash price at the time of harvest or after storage, or deliver to a grain pool, run by a marketer.

Daily canola prices can be sourced online, from the grower’s preferred marketer or agricultural newspapers.

Risks & Regulations

Risks/challenges

Risk is inherent in all agricultural pursuits and some of the risks associated with cropping include:

  • the crop failing to establish or mature properly due to adverse weather events, thus resulting in reduced harvest tonnage and/or poor quality grain
  • commodity prices falling during the growth period impacting on the returns projected at planting
  • not recouping the costs of inputs and capital invested in the crop, like fertiliser or the costs of running large equipment, if the crop fails

Canola is considered a high risk and high maintenance crop due to the following factors:

  • it requires a high degree of monitoring and control of pests, diseases and weeds
  • it has higher nutrition requirements than cereals
  • nutrition strategies vary from season, district and variety, meaning additional understanding about inputs is required every year
  • it is susceptible to frost damage
  • if using windrowing, it means two machines passes through the same paddock in a short period of time, which is time-consuming and costly.

Risks are generally considered lower in high rainfall zones. However, newer shorter season varieties are reducing risk in the medium to low rainfall districts. To mitigate risk in growing crops, careful attention must be paid to the following agronomic factors; paddock selection, weed control, fertiliser strategy, blackleg management, variety selection, seeding date, seeding depth, insect control and timeliness of windrowing and harvest.

Regulatory considerations

The regulatory considerations that apply to all Australian grain farms, including laws applying to chemical use and management, occupational health and safety and transport (including machinery movements and the loading/unloading of harvested grain), apply to canola operations. In addition, policies on GM crops may limit the varieties grown in certain states.

Over time, states have developed and revised policies in relation to approvals for the production of GM canola. Further information on GM canola can be obtained from the relevant state or territory department of primary industries or agriculture.

More information about general laws and regulations affecting new canola growers (and grain growers generally) can be obtained from the relevant government authority. Information and advice can also be sought from the relevant state farming organisation, some of which are listed on the National Farmers’ Federation website or the Australian Oilseeds Federation.

Publications

Publications/information

The Australian Oilseed Industry – Australian Oilseed Federation

Better canola: Module 7 – Harvest Management – NSW Department of Primary Industries (2012)

Fact Sheet Blackleg management guide – GRDC (2018)

Growing Canola – Agriculture Victoria (2012)

Over the bar with better canola agronomy: Demonstration and trial results, crop establishment case studies – GRDC (2010)

Canola: Best practice management for south-eastern Australia – GRDC (2009)

Growing Western Canola – Oilseeds WA (2006)

Diseases of canola and their management: the back pocket guide – GRDC (2013)

Other resources

National Variety Trials – a national program of comparative crop variety testing

Grains Research and Development Corporation – the Australian grains research organisation

Canola New South Wales Department of Primary Industries

Growing canola – Agriculture Victoria

Better Canola: Module 8 – Safe storage Australian Oilseeds Federation (2012)

Canola to biodiesel: a closed-loop system on the website Biomass Producer – Bioenergy information for Australia’s primary industries RIRDC (2013)

Image Gallery

 - image

Sowing a canola crop

 - image

Ryegrass weeds in a canola crop

 - image

Harvesting a canola crop

 - image

Canola oil

 - image

Field of canola in flower

 - image

A bee pollinating a canola flower

 - image

Canola seed which is crushed to produce vegetable oil (source ABC Australia)