Super high oleic safflower – a game changer for grain growers
Take home messages
- Safflower is a winter/spring growing crop that is:
- heat and drought tolerant,
- moderately tolerant of sodic and saline soils,
- suited to both dryland and irrigation farming systems,
- low input, low maintenance and easy to grow, and;
- has machinery requirements similar to cereal /canola production.
- Super high oleic safflower has been developed by GRDC and CSIRO as an alternate high value cash crop with rotation benefits, that produces a minimum of 90% oleic acid in every litre of oil produced.
- Super high oleic safflower oil is being produced for a range of Australian and global industrial markets including lubricants, plastics, polymers, resins, cosmetics and biofuels.
- Following the granting of all required regulatory approvals super high oleic safflower was released in Australia for commercial production in 2019.
Plant-derived oils are mixtures of saturated, monounsaturated and polyunsaturated fatty acids in ratios that can be less than ideal for certain industrial uses which have specific performance requirements. Large volumes of crude vegetable oil are used as feedstocks for the oleochemical industry and provide the opportunity to access the growing bio-base market segment.
Safflower (Carthamus tinctorius L.) seed produces oil that predominantly contains monounsaturated fatty acid (C18:1; oleic acid) and polyunsaturated fatty acid (C18:2; linoleic acid). While both have commercial uses, it is the valuable oleic acid that is used as a replacement to petroleum-based precursors in the manufacture of plastics, lubricants and cosmetics, etc.
Traditional breeding programs have developed safflower seed with oleic acid levels in the range of 75–85%. However, like other oilseeds, the remaining linoleic acid component, at 12-18%, is not desirable for industrial use because it is unstable and difficult to remove during oil processing. Therefore, it is desirable to develop a safflower seed that accumulates high oleic acid (C18:1) but contains very low linoleic acid (C18:2) and zero linolenic (C18:3) content. (Wood et al, 2018)
CSIRO scientists utilising their patented seed-speciﬁc hairpin-based RNAi to two safﬂower lipid biosynthetic genes, FAD2.2 and FATB have produced seed oil containing minimum 90% oleic content and at the same time less than 1.5% polyunsaturates and only 4% saturates. Due to the high level of oleic content, the oil derived from the safflower plant is referred to as Super High Oleic Safflower oil (SHOSO).
Safflower (Carthamus tinctorius L.) is an herbaceous annual and a member of the Asteraceae/Compositae (sunflower) family. It is native to parts of Asia, the Middle East, and Africa. It was grown mainly for its flowers, which were used in making dyes for clothing and food. Today, it is grown mainly for its oil. Safflower evaluations in Australia started in the 1940s amid concerns for drying oil shortages in the paint and resin industries (Smith 1996). Several cultivars were subsequently introduced from overseas, allowing small scale commercial production to commence in the mid-1950s.
The abolishment of quotas on the use of vegetable oils for margarine production in 1976 led to increased interest in oilseed production and in the following seasons record prices were paid for safflower (Smith 1996). The area sown in Australia subsequently peaked in 1979 with 74,688ha (Smith 1996). Production in the 1980s was concentrated in the south-east of South Australia, the Western District of Victoria and northern New South Wales. Following the demise of the marketing channels for safflower in the late 1980s production has since been limited to approximately 4,000 to 6,000ha per year for sale into the bird seed market.
In two studies of safflower growers in Victoria and southern NSW (Wachsman et al., 2010) and northern NSW (CSIRO 2014) growers were asked why they included safflower in their crop rotations (Table 1). Key reasons that were important in both studies were improved soil structure, improved weed and disease control, low input costs and spreading the work load.
Table 1. Reasons growers include safflower in their crop rotations (Wachsman et al., 2010).
Reasons for growing safflower in your crop rotation?
(Victoria / Sth. NSW)
2010 Responses (%)
Reasons for growing safflower in your crop rotation?
2014 Responses (%)
Improves soil structure
Opportunity crop when the sowing window for other winter crops has closed.
Good weed control tool
Spreads workload for both planting and harvest times.
Water use/profile drainage
Disease, weed or insect pest break in the rotation.
Flexible time of sowing
Attractive market prices.
Low input/cheap to grow
Low nutritional inputs needed to grow the crop.
Easy to grow
Breaks up a compacted profile or a hardpan.
Dries out a saturated profile.
Deters pests; pigs, kangaroos and emus.
Non cereal/pulse option 2 4
Safflower is thistle-like, with a main stem and numerous branches. It stands 0.35m to 1.2m tall at maturity. Its taproot can penetrate 2.5m to 3.0m depending on subsoil temperature and moisture (Figure 1).
Figure 1. The development of a safflower plant (Source: Kaffka and Kearney, 1998).
Safflower takes one to two weeks to germinate. After emergence, it stays two to four weeks in the rosette stage. Early growth and development is slow, but growth is rapid from the stem elongation stage. Each plant produces numerous flower heads. Flower petals are red, white, yellow or orange. Each head contains 20 to 100 seeds. The seed is the same size as plump barley. Seeds are glossy white, brown, or white with grey, black, or brown stripes. On average, safflower is ready to harvest about 35 to 40 days after the peak of flowering.
Super high oleic safflower end uses
Super high oleic safflower oil (SHOSO) is a renewable, biodegradable alternative to petroleum-based raw materials with multiple applications in the bio-lubricants, biochemical and bioplastics industries (Figure 2).
Figure 2. Market opportunities for super high oleic safflower oil.
Recent research completed by scientists at Montana State University Advanced Fuels Centre compared the performance of a lubricant oil formulation based on GO Resources super high oleic oil versus a synthetic lubricant oil (e.g. Mobil 1). The following results for a lubricant oil formulation based on SHOSO were reported (Johnson, D. 2019 pers comm.):
- Reduced friction over synthetic oils by 83%.
- Reduced friction over conventional oils by 124% (Figure 3).
- Reduced tailpipe emissions by 48%.
- Reduced engine wear.
- Increased fuel economy >10% (actual usage in cars).
- Reduced environmental contamination.
- 100% recyclable.
Figure 3. Reduced friction over conventional oils (Source: Montana State University Advanced Fuels Centre. June 2019).
The meal that remains after oil extraction can be used as a valuable feedstuff for livestock rations. The meal from dehulled seeds has a high protein content (40 percent) and low fibre.
Conditions for growing safflower
Safflower is adaptable to a wide range of soils, but the best soils for production are deep, fertile and well-drained. Safflower should not be planted in poorly drained or cool, wet soils as these conditions can delay uniform emergence.
Safflower is more tolerant of saline and sodic soils (Yeilaghi et al 2016, Hussain et al 2015, Shaki 2018, Pooran 2016, Biosalinity News July 2012, Subsoils Manual 2009) than small grains and canola because of its deep tap root. Due to its deep taproot, safflower can be used in a tactical role on problem soils to break up hard pans and improve water and air infiltration into the subsoil through the creation of pores.
Safflower is a sun loving crop, and high temperatures and bright sunny days in July through to early September speeds development. Seeds germinate when soil temperatures are above 4.5°C with germination rates increasing with higher temperatures after sowing. Plants cannot withstand freezing temperatures after flowering. It grows well in both dryland and irrigated areas. It is a drought-tolerant plant though moisture is important at planting. Plants need dry atmospheric conditions during flowering and seed filling for proper head set (Figure 4).
Figure 4. Safflower production locations in Australia.
Although safflower is regarded as drought tolerant, it actually has a high water requirement. It survives dry conditions by developing an extensive tap root and scavenging for deep soil water, rather than relying on growing season rainfall. This assumes that deep soil water is present and that adverse soil conditions do not restrict root fill.
Safflower’s relatively high water requirement is often ascribed to its relatively long growing season and some water must be available to crops during flowering and seed fill. Safflower performs best in regions that receive more than 450mm of rainfall annually but yields exceeding 1t/ha can be expected on clay soils that are wet to 1m depth at sowing, providing at least 50mm of post-sowing rainfall is received.
Safflower will emerge at soil temperatures above 4°C, but 15°C is considered optimal. It tolerates frosts to -7°C during the rosette stage, but frosts below -4°C during stem elongation and branching can damage the growing point and split stems. Provided damage is not too extensive the plant can partially compensate by producing new shoots from below the damaged area. Safflower matures during December and January when temperatures are often high in traditional cereal growing regions. It can tolerate these temperatures providing sufficient moisture is available.
Seedbed preparation is no different from that of wheat or barley. A moist, firm, weed-free seedbed is required. Safflower doesn’t do well when there is soil crusting. The crop is a poor competitor with weeds, especially in the early stages of growth, when it has not started branching. Presence of weeds at this time is detrimental. It is important to eliminate weeds before you plant the crop. Use registered knockdown herbicides and/or cultivation to control weed growth prior to planting.
Safflower is ideally sown into moist soil with equipment such as press wheels to provide good seed-soil contact. Sowing depth will vary with soil type and conditions but is normally between 2 and 5cm. Sowing deeper can delay emergence and reduce early vigour, leaving crops more susceptible to pests, diseases and competition from weeds. One advantage of safflower is that it compensates for poor emergence by producing extra branches, extra heads, and extra seeds per head.
Safflower development is controlled by a combination of temperature and day length. Large delays in the time of sowing therefore have a much smaller effect on the timing of flowering. This is because crops progress through the vegetative fill stages much more rapidly, with only a small effect on the period between flowering and maturity (Figure 5). The development of safflower is hastened in seasons that are warm and dry due to higher temperatures in the crop canopy (Figure 6).
Figure 5. Effect of sowing in mid-June and mid-August on safflower development at Moree and Leeton in NSW (Source: Adapted from Colton, 1988).
Figure 6. Effect of sowing in mid-July and mid-September on safflower development in a wetter and drier season at the same location in the Victorian Wimmera (Source: Adapted from Colton, 1988).
Target plant populations and seeding rates for safflower over a range of environments are provided in Table 2.
Table 2. Seeding rates of safflower for different regions and different climatic conditions (Source: GRDC. Raising the Bar with Better Safflower Agronomy, 2010).
Northern & central NSW
(12 – 15kg/ha)
(18 – 22kg/ha)
Victoria & SA
(18 – 24kg/ha)
(12 – 18kg/ha)
Safflower’s nutrient needs generally depend on the following:
- Yield goal
- Soil test results
- The sequence of the crop in the rotation
Safflower’s deep taproot allows it to reach nutrients that may be unavailable to small grains. Growers may need to apply more fertiliser if safflower follows deep-rooted crops in rotations.
At least 30kg/ha of nitrogen should be applied to most dryland crops and this can be increased to over 100kg/ha for high yielding crops under irrigation. No more than 20kg/ha of nitrogen should be drilled with seed to avoid toxicity, which will reduce crop establishment.
As a general rule of thumb 12 to 20kg/ha of phosphorus is recommended on deficient soils. Responses to phosphorus are unlikely on soils with Cowell P levels above 40mg/kg, although small amounts can still be applied at sowing to improve early growth and maintain soil levels.
Safflower uses moderate amounts of potassium, but most soils in the cereal growing regions of Australia contain adequate levels. The general exception is sandy soils, which are not best suited for safflower production unless in high rainfall regions. Potassium is not very mobile in soils, so where required it is best banded under seed.
Many soils contain adequate sulphur levels for safflower production. Soil sulphur levels should be monitored with soil tests and sulphur can be applied as gypsum or as a component of a blended fertiliser when necessary.
Manganese, Iron and Zinc
On certain soil types, such as the black soils in northern New South Wales or the heavy black or grey clay over limestone soils in South Australia, safflower does respond to manganese, iron and/or zinc. These are best applied as a foliar application around six weeks after sowing if necessary.
Safflower competes poorly with weeds, especially from early growth through the rosette stage, when branching has not yet occurred. It is critical to have effective pre-plant weed control. Weeds have reduced safflower yields by up to 75 percent, depending on the species and numbers.
Due to the limited number of herbicides registered for weed control in safflower in 2016, GO Resources commenced an on-going herbicide safety screen for a range of pre-emergent and post-emergent herbicides. The research by GO Resources contributed to the Australian Pesticides and Veterinary Medicines Authority (APVMA) decision in 2019 to grant the Australian Oilseeds Federation (AOF) minor use permits for the application of clethodim (PER86859) and S-Metolachlor (PER86858) (Dual Gold®) in safflower. Current minor use applications that are being prepared for submission to the APVMA for use in safflower include the herbicides propyzamide, pyroxasulfone (Sakura®) and prosulfocarb + S-Metolachlor (Boxer Gold®). Refer to the APVMA permits portal to confirm permits are in place prior to the use of these chemicals. Table 3 provides a summary of the current herbicides approved and being screened for use in safflower.
Table 3. Current herbicides approved in 2019 for use in safflower (Source: GO Resources).
APVMA Minor Use Permit
in Safflower - Status
Granted in 2019
Applied for in 2019 for the 2020 Season
In periods of higher than normal rainfall, fungal diseases such as Phytophthora root rot, Alternaria leaf spot (Alternaria cartharmi), Pseudomonas bacterial blight (P. syringae) and Sclerotinia rot can cause serious losses. Fusarium and Verticillium wilts and Botrytis head rot also have caused serious losses.
To reduce disease severity, it’s important to:
- Plant certified seed that has been treated with appropriate seed treatments.
- Utilise proper crop rotation practices that will reduce the risk of diseases being present in safflower.
Do not plant safflower before or after safflower, pulse crops, sunflower, mustards or canola. These crops are susceptible to Sclerotinia head rot. Leave at least four years between susceptible crops.
Safflower is most susceptible to damage by insects during establishment and between budding and harvest. Numerous insect pests have been observed on safflower and while some are widespread, others are confined to certain regions and climates.
There are a few insect problems in safflower. Red legged earth mites, wireworms and cutworms can damage seedlings. Rutherglen bug, grasshoppers and lygus bugs can damage the crop, but control is only necessary when they reach levels that cause serious losses.
If insects are present it is recommended that growers consult with their local agronomist to confirm the insects’ presence and for advice on the appropriate registered insecticide that can be applied for control.
Harvest and storage
The crop is ready for harvest when most of its leaves have turned brown with only a tint of green remaining on the bracts. The stem must be dry.
Moisture content should be eight percent or lower for proper storage. If the crop is cut at higher moisture content, dry it.
It is recommended to harvest a small sample and measure the moisture content. Direct heading is better than windrowing because it reduces shattering losses and seed quality is better.
Safflower can be harvested using the same machinery used for cereals. Ground speed is generally 25 percent slower than for cereals. This is mainly to reduce grain losses, but also to reduce the chance of blockages which can be time consuming and uncomfortable to rectify due to the crop’s spines. Header settings will vary with conditions, crop yield and the type of machinery used.
Reels should be set to gently push the crop over the cutter bar without dislodging seed from the seed head. Drum speeds are generally slower (~500rpm), and concave openings usually wider (~16mm at front, ~13mm at back) than used for cereals. This is to prevent the cracking of seed which will deteriorate oil quality and reduce the value of the crop. Wind settings are typically about two-thirds of that required for wheat.
References and useful resources
Evaluating the potential roles of safflower (Carthamus tinctorius L.) in Southern Region cropping systems. (Rob Norton, 2003 GRDC Project Code UM 132)
Growing safflower in Australia: Part 1 - History, experiences and current constraints on production. (Jochinke et al, 2010)
Growing safflower in Australia: Part 2 - Agronomic research and suggestions to increase yields and production (Wachsmann et al, 2010)
Hussain, M.I., Lyra, DA., Farooq, M. et al. (2016) Salt and drought stresses in safflower: a review. Agron. Sustain. Dev. (2016) 36: 4.
Pooran G. (2011). Inheritance of salt tolerance in safflower (Carthamus tinctorius L.). Advances in Environmental Biology. 5. 3694-3699.
Shaki, H. et al (2018) Growth enhancement and salt tolerance of Safflower (Carthamus tinctorius L.), by salicylic acid, Current Plant Biology, Volume 13, 2018, Pages 16-22.
Wood, C et al (2018) Seed-specific RNAi in safflower generates a super high oleic oil with extended oxidative stability. Plant Biotechnol J. 2018 Oct;16 (10):1788-1796. Epub 2018 Apr 2.
Yeilaghi, H. et al (2012) Effect of salinity on seed oil content and fatty acid composition of safflower (Carthamus tinctorius L.) genotypes, Food Chemistry, Volume 130, Issue 3, 2012, Pages 618-625.
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