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Putnam, D.H., J.T. Budin, L.A. Field, and W.M. Breene. 1993. Camelina: A promising low-input oilseed. p. 314-322. In: J. Janick and J.E. Simon (eds.), New crops. Wiley, New York.

Camelina: A Promising Low-Input Oilseed

D.H. Putnam, J.T. Budin, L.A. Field, and W.M. Breene

  1. DESCRIPTION & ADAPTATION
  2. AGRICULTURAL HISTORY
  3. UNIQUE AGRONOMIC QUALITIES
    1. Yield Potential
    2. Winter Seeding
    3. Compatibility with Cover Crops
    4. Fertilizer and Water Needs, Insects and Diseases
    5. Weed Control
  4. UTILIZATION
    1. Seed Composition, Oil Content and Meal Quality
    2. Fatty Acid Composition and Use of the Oil
  5. SUITABILITY FOR SUSTAINABLE AGRICULTURE
  6. REFERENCES
  7. Table 1
  8. Table 2
  9. Table 3
  10. Table 4
  11. Table 5
  12. Table 6
  13. Fig. 1
  14. Fig. 2
The production of edible oil from crops has enjoyed unremitting growth during the latter part of the 20th century. In a six year period in the 1980s, a 26% increase in production of oils from ten oilseeds was realized. Much of this growth has been in tropical oils (oil palm, Elaeis guinensis L.) or high quality (low saturated fat) edible oils such as soybean [Glycine max (L.) Merr.], canola (Brassica napus L.), and sunflower (Helianthus annuus L.). This trend shows no signs of relenting. The demand for edible oils is increasing most in the heavily populated regions of South Asia, China, and the Far East, where vegetable oils are an important part of the diet, but demand for meal and oil is also high in the European and American markets and the Commonwealth of Independent States.

The development of soybean, sunflower, and canola, the three most significant edible oils for temperate climates, represent important new crop successes (Robinson 1973; Hymowitz 1990; Downey 1990). It is likely that these crops will continue to expand in hectarage, given increasing demand for high quality edible oils and meals, the wide adaptation of these crops, and new, improved cultivars. However, each of these major oilseeds has its limitations. For example, soybean, though ideal for most regions of the corn belt, is not well adapted to more northerly regions of North America, Europe, and Asia. Canola and sunflower are better adapted to northern climates but have high nitrogen requirements (especially canola), and are susceptible to insect or bird predation as well as diseases. These oilseed crops are not often suitable to marginal lands (low moisture, low fertility, or saline soils). In recent years, there has been increasing interest in developing agronomic systems with low requirements for fertilizer, pesticides, and energy, and which provide better soil erosion control than conventional systems (NRC 1989). This led us to examine the viability of developing camelina as an oilseed with reduced input requirements and as a crop well suited to marginal soils, or soil- and resource-conserving agronomic practices.

DESCRIPTION & ADAPTATION

Camelina sativa (L.) Crantz., Brassicaceae (falseflax, linseed dodder, or gold-of-pleasure) originated in the Mediterranean to Central Asia. It is an annual or winter annual that attains heights of 30 to 90 cm tall (Fig. 1) and has branched smooth or hairy stems that become woody at maturity. Leaves are arrow-shaped, sharp-pointed, 5 to 8 cm long with smooth edges. It produces prolific small, pale yellow or greenish-yellow flowers with 4 petals. Seed pods are 6 to 14 mm long and superficially resemble the bolls of flax. Seeds are small (0.7 mm x 1.5 mm), pale yellow-brown, oblong, rough, with a ridged surface. Morphology and distribution of camelina species has been described by Polish and Russian botanists (Mirek 1981). Camelina has been shown to be allelopathic (Grummer 1961; Lovett and Duffield 1981).

Camelina is listed as being adapted to the flax-growing regions of the northern Midwest (Minnesota, North Dakota, South Dakota) (NC-121 1981). It is primarily a minor weed in flax and not often a problem in other crops and does not have seed dormancy (Robinson 1987). However, the adaptation of camelina as a crop has not been widely explored. Similar to the other Cruciferous species, it is likely best adapted to cooler climates where excessive heat during flowering is not important. There are several winter annual biotypes available in the germplasm, and it is possible that camelina could be grown as a winter crop in areas with very mild winters. Camelina is short-seasoned (85 to 100 d) so that it could be incorporated into double cropping systems during cool periods of growth, possibly in more tropical environments.

AGRICULTURAL HISTORY

Although camelina is known in North America primarily as a weed, it was known as "gold of pleasure" to ancient European agriculturists. Cultivation probably began in Neolithic times, and by the Iron Age in Europe when the number of crop plants approximately doubled, camelina was commonly used as an oil-supplying plant (Knorzer 1978). Cultivation, as evidenced from carbonized seed, has been shown to occur in regions surrounding the North Sea during the Bronze Age. Camelina monocultures occurred in the Rhine River Valley as early as 600 BC Camelina probably spread in mixtures with flax and as monocultures, similarly to small grains, which also often spread as crop mixtures. It was cultivated in antiquity from Rome to southeastern Europe and the Southwestern Asian steppes (Knorzer 1978).

Camelina declined as a crop during medieval times due to unknown factors, but continued to coevolve as a weed with flax, which probably accounts for its introduction to the Americas. Like rapeseed oil, camelina oil has been used as an industrial oil after the industrial revolution. The seeds have been fed to caged birds, and the straw used for fiber. There have been scattered hectarages in Europe in modern times, mostly in Germany, Poland, and the USSR, and some efforts were made in the 1980s at germplasm screening and plant breeding (Enge and Olsson 1986; Seehuber and Dambroth 1983; Seehuber and Dambroth 1984: Kartamyshev 1985). Camelina has been evaluated to some extent in Canada (Downey 1971) and to a larger extent in Minnesota where R.G. Robinson conducted agronomic studies on camelina (Robinson 1987). However, there has been relatively little research conducted on this crop worldwide, and its full agronomic and breeding potential remains largely unexplored.

UNIQUE AGRONOMIC QUALITIES

Yield Potential

Field studies on camelina have been conducted at the University of Minnesota for over 30 years (Robinson 1987). In one 9-year/location yield comparison, camelina was shown to have a yield potential similar to that of many other Cruciferae (Table 1), but it differed in seed size, maturity, lodging resistance, and oil percentage. Yields of camelina cultivars (Table 2) have been in the 600 to 1,700 kg/ha range at Rosemount, Minnesota (45° N latitude), averaging about 1,100 to 1,200 kg/ha over many years of trials. It should be noted that the yield of many of these oilseeds (especially B. napus) has been improved significantly through plant breeding and improved agronomic practices, whereas camelina has largely not had the benefit of plant breeding. Under Minnesota conditions, yields of all spring-sown cruciferous oilseeds are much higher at more northerly locations (1,736 kg/ha long term average canola yield--Roseau, Minnesota), compared with yields at Rosemount, which is located near St. Paul. Camelina is much smaller seeded and earlier maturing than the other cruciferae tested. Lodging was comparable to or fact slightly superior to the other cruciferae oilseeds tested (Table 1), and there was significant variation for lodging among camelina varieties (Table 2).

Some variation in camelina maturity, lodging resistance, seed weight, and oil percentage was exhibited by the lines tested and by other germplasm screening not reported here, but many of these lines were similar in yield at Rosemount (Table 2). Certainly increases in yield might be generated through plant breeding. German plant breeders using the single-seed descent method, have found transgressions over parental lines in many yield traits for camelina, demonstrating both the high yield potential and capacity for yield improvement in this species (Seehuber et al. 1987). This experience indicates that camelina, unlike some wild species undergoing domestication, exhibits yield potential and oil content which are both currently agronomically acceptable and amenable to improvement through plant breeding.

Winter Seeding

The practice of broadcasting camelina seed on frozen ground in late November or early December has been tested over a number of years at Rosemount, and the practice appears to be viable (Table 3). In one four-year study, crops were sown with standard farm machinery on large plots. Camelina was sown in late fall on stubble, without seedbed preparation or herbicides, or conventionally in the spring and compared with flax sown conventionally and sprayed with herbicides (dalapon and MCPA). Performance of winter-sown camelina was equal or superior to conventionally-sown flax in these studies.

To confirm these results, a separate two-year study was conducted where camelina and flax were surface-seeded by hand in both winter and spring on tilled or stubble ground, broadcast or by machine without herbicides (Table 4). In 1990-91, surface seeding in winter was unsuccessful with flax, but was successful with camelina, producing significantly earlier emergence and fewer weed problems. However, in the 1989-90 study, the winter seeding was unsuccessful for both crops, probably due to an open winter. Surface seeding of camelina seemed to work better under no-till conditions, possibly due to superior microsite protection for the small seed and seedling, and prevention of wind dispersion of the seed. Machine planting was no better than broadcasting in the spring sowings. Machine planting in December was not feasible. A winter-sown stand of camelina emerges mid-April in Minnesota, before most other spring-sown crops, and before significant weed flushes.

These trials showed that camelina sown without herbicide or tillage yielded as well or better than flax grown conventionally. These studies also showed that camelina, unlike flax, can be surface-sown on frozen ground in the late fall or winter or early spring and produce good stands and yields comparable to conventionally-sown Cruciferae crops.

Compatibility with Cover Crops

In a three-year study, winter-sown camelina yielded an average of 9% more when seeded with a fall-sown cover crop than without (Table 5). In this and in subsequent studies (Robinson 1987), camelina has produced better stands, weed control, and yields when planted in the winter with a cover crop compared with seeding after conventional tillage in the spring or surface seeding on bare ground in the fall. These data indicate that camelina is highly compatible with cover crops used for fall and early spring soil erosion control.

Fertilizer and Water Needs, Insects and Diseases

The soil fertility needs of camelina are likely similar to those of other crucifers with the same yield potential. Camelina has been shown to respond to nitrogen similarly to mustard or flax (Robinson 1987).

Bramm et al. (1990) found that camelina was better able to compensate for early water deficits than flax or poppy. This drought-avoidance characteristic might make camelina better suited to drier regions than other oilseeds.

Downy mildew (Peronospora camelinae), a white or gray mold on the upper part of the stem is sometimes observed in camelina (Robinson 1987). Transmission of Turnip Yellow Mosaic virus by camelina seed has been reported (Hein 1984). However, camelina has been reported to be highly resistant to blackleg (Lepotosphaeria maculans) which is a significant disease problem with canola (Salisbury 1987). Camelina has also been found to be very resistant to Alternaria brassicae, compared with turnip rape or swede rape (Grontoft 1986; Conn et al. 1988).

Flea beetle [Phyllotreta cruciferae (Goeze)] is also sometimes observed on camelina, although it is not nearly the problem it is with canola. However, in extensive multi-year small-plot trials, damage due to insects and diseases in camelina have not been sufficient to warrant control measures (Robinson 1987).

Weed Control

The compatibility of canola with commonly used herbicides is not widely known. In one three-year trial, camelina was not injured by trifluralin incorporated either in the fall or spring, but yields were not improved over winter-seeded camelina planted without herbicide (Robinson 1987). No herbicides are currently labeled for use with camelina, and herbicides would comprise a significant cost of production should any in the future even become labeled for such use. These data however, suggest that the use of preemergence herbicides may not be necessary in camelina if it is seeded in the winter or very early spring. Winter-seeded camelina emerges earlier than conventionally seeded camelina or other cruciferous crops, and normally before any substantial weed germination in the spring. The seedlings are quite cold-tolerant, surviving several freezes in the spring. For example, in one trial, a May 12 frost (-2°C) injured mustard, rape, and flax, but did not affect camelina (Robinson 1987). Individual camelina seedlings are fairly small and non-competitive, but this early-emerging, cold-tolerant characteristic, especially when planted at high densities, provides excellent competition with many annual weeds.

Perennial or biennial weeds are likely to be more difficult to control in camelina. However, the competitiveness of camelina with annual weeds presents the possibility that camelina could be grown both without tillage and without preemergence weed control, both significant costs of production and environmental risk-factors.

UTILIZATION

Seed Composition, Oil Content and Meal Quality

The oil content of camelina seed has ranged from 29 to 39% in our studies. There appears to be some variation for oil content among the cultivars tested (Table 2), but the germplasm has not been widely characterized. Studies in Germany have shown oil content to range between 37 and 41% and seed protein content 23 to 30% (Marquard and Kuhlmann 1986). Camelina appears to be similar in protein content and elemental composition to flax (Linum usitatissimum L.), with the exception of a higher sulfur content (Robinson 1987). Camelina meal is comparable to soybean meal, containing 45 to 47% crude protein and 10 to 11% fiber (Korsrud et al. 1978).

Zero to trace levels of volatile isothiocyanates have been found in camelina meal (Peredi 1969; Korsrud et al. 1978; Sang and Salisbury 1987) compared with crambe (Crambe abyssinica Hochst) or industrial rapeseed meal which contains substantially higher levels of glucosinolates. Laboratory mice fed camelina meal gained less weight than those fed casein or egg control diets, but more than those fed crambe meal (Korsrud et al. 1978). Although some essential amino acids may have been limiting in the camelina meal diets, some growth depressing factor other than glucosinolates may have been present (Korsrud et al. 1978).

Camelina has been fed to wild (Fogelfors 1984) or caged (Mabberly 1987) birds, and this is one potential use. Other potential uses include applications as an ornamental, a cover or smother crop, a border row for experimental field plots, or in dried flower arrangements (Robinson 1987).

Fatty Acid Composition and Use of the Oil

Oil was extracted from camelina and other oilseeds by the Soxhlet method using diethyl ether, and fatty acids determined using the method of Enig and Ackerman (1987). The fatty acids in camelina oil are primarily unsaturated, with only about 12% being saturated (Fig. 2). About 54% of the fatty acids are polyunsaturated, primarily linoleic (18:2) and linolenic (18:3), and 34% are monounsaturated, primarily oleic (18:1) and eicosenoic (20:1) (Table 6).

Our values for fatty acid composition of Camelina sativa are generally similar to those reported for Camelina rumelica (Umarov et al. 1972), or other reports on Camelina sativa (Seehuber and Dambroth 1983). With its low saturated fat content camelina oil could be considered a high quality edible oil, but it is also quite highly polyunsaturated, which makes it susceptible to autoxidation, thus giving it a shorter shelf life. With an iodine value of 144, it is classified as a drying oil (Robinson 1987). Camelina oil has been used as a replacement for petroleum oil in pesticide sprays (Robinson and Nelson 1975).

Camelina oil is less unsaturated than linseed (flax) oil and more unsaturated than sunflower or canola oils (Fig. 2, Table 6). The balance of saturated vs. unsaturated fats is similar to that of soybean, but camelina contains significantly higher proportion of C18:3 fatty acids. Camelina seems to be unique among the species evaluated in having a high eicosenoic acid content in the oil, but the potential value or disadvantage of this is currently unclear.

The erucic acid content is probably too low for use in the same applications as crambe or high erucic acid rapeseed, where a high erucic acid content is desired. Most of the camelina lines evaluated contain 2 to 4% erucic acid (Table 6), which is greater than the maximum (2%) limits for canola-quality edible oil. However, in a preliminary germplasm screen, we have identified lines with zero erucic acid content (data not shown), so it is likely that this trait could readily be removed through plant breeding, as it has been with canola.

The lack of clear utilization patterns for camelina oil currently limit its use. The fatty acid composition does not currently uniquely fit any particular use. Manipulation of camelina fatty acid content, which has been achieved in other oilseeds, could greatly improve the utilization possibilities of this crop.

SUITABILITY FOR SUSTAINABLE AGRICULTURE

When analyzing the potential role of a new crop, unique attributes of that species must be established; it must contribute something not already provided by existing crop species. It is not sufficient, for example, for a crop simply to become "another oilseed." There must be unique and compelling properties of that crop to provide incentives for further development.

The research reported here has shown that camelina possesses unique agronomic traits which could substantially reduce and perhaps eliminate requirements for tillage and annual weed control. The compatibility of camelina with reduced tillage systems, cover crops, its low seeding rate, and competitiveness with weeds could enable this crop not only to have the lowest input cost of any oilseed, but also be compatible with the goals of reducing energy and pesticide use, and protecting soils from erosion. Camelina is a potential alternative oilseed for stubble systems, winter surface seeding, double cropping, or for marginal lands. At a seeding rate of 6 to 14 kg/ha, camelina could be inexpensively applied by air or machine-broadcast in early winter or spring on stubble ground without special equipment. Although these unimproved lines have been shown to be agronomically acceptable, modern history has indicated the Cruciferae to be highly manipulatable through plant breeding or biotechnology, and so the promise of improvement is also high. The meal does not contain glucosinolates, but the fatty acid composition of the seed needs to be modified to provide a role for the crop in the oilseeds market.

Lack of clear utilization patterns currently limit the crop, and further work on oil, meal, and seed use is required. The possibilities of using camelina in human food, as birdseed, as an edible or industrial oil, a fuel, or other applications remains largely unexplored. Further utilization and breeding research is required to more fully make use of the unique agronomic qualities that this crop possesses.

REFERENCES

Table 1. Comparison of Camelina with other oilseedsz.

Species Yield (kg/ha)y Oil (%) Seed size (g/1,000 seeds) Maturity date Lodging (%)
Camelina sativa 1277 31 0.6-1.2 7/1-7/28 20-30
Crambe abysinica 1317 32 6-8 7/15-8/10 30-50
Brassica napus 1273 39 2.9-4.0 8/1-8/20 40-80
Brassica hirta 1319 24 4.8-5.1 7/20-8/3 20-80
zData from trials conducted 1960-1985 in Rosemount and Roseau, MN; 9 year/location means (Robinson 1987).
yYields of some species, especially B. napus have improved due to plant breeding efforts since these trials were conducted. Yields of all cruciferae were at least 50% higher at Roseau (near Canada) vs. Rosemount in these trials.

Table 2. Yield and characteristics of Camelina sativa lines grown in Rosemount, Minnesota, 1991.

Days from planting to
Line (origin) Full bloom Maturity Height (cm) Lodging ratingz 1,000 seed weight (g) Seed yield (kg/ha) Oil (%)
C028 (USSR) 42 77 58 7.2 1.08 1007 37.5
C037 (Germany) 45 79 67 3.4 0.98 1085 35.3
C046 (Germany) 45 78 63 1.6 1.14 1159 37.3
C053 (Germany) 46 80 64 4.2 0.72 1065 36.4
C054 (Germany) 45 81 68 1.0 1.22 1140 35.1
C082 (Germany) 45 80 67 3.1 0.94 1218 35.9
C088 (Germany) 45 79 60 2.4 0.83 1148 35.5
'Robbie' (USA) 46 78 56 1.5 0.65 1067 34.3
LSD (P<=0.05) 2 1 6 1.8 0.10 173 2.4
C.V. (%) 4 2 6 39 7 11 ---
z1 = no lodging; 10 = severe lodging.

Table 3. Comparison of winter-sown camelina with spring-sown camelina and flax.

Seed yield (kg/ha)
Cropz Sowing date Sowing rate (kg/ha) Tillage Weed control (%)y 1970 1971 1972 1973 Ave.
Camelina Early Dec. 12 No 77 862 840 1243 1747 1176
Camelina Mid-April 8 Yes 69 762 840 1288 1725 1154
Flax Mid-April 56 Yes 76 963 336 952 1848 1019
LSD (P<=0.05) 202 157 146 146 78
zCamelina was grown without herbicides and flax was sprayed with dalapon and MCPA. Data from Robinson (1987).
yPercent of weeds controlled estimated by visual rating (100 = least weedy).

Table 4. Effect of tillage, seeding method, and time of seeding on camelina and flax, Rosemount, Minnesota, 1990-91.

Days from planting to
Treatments Stand (%) Full bloom Maturity Lodging ratingz Weeds (%)y Height (cm) Seed yield (kg/ha)
No-till stubble
Flax winter scatter 4 6/15 7/21 1 100 52 91
Flax spring scatter 35 6/15 7/22 1 75 51 801
Flax spring machine 98 6/15 7/22 1 61 47 851
Camelina winter scatter 93 6/1 6/28 1 16 59 749
Camelina spring scatter 64 6/9 7/7 1 48 41 1008
Camelina spring machine 100 6/13 7/12 2 63 52 888
Tilled
Flax winter scatter 3 6/14 7/21 1 100 51 142
Flax spring scatter 68 6/12 7/21 1 80 56 837
Flax spring machine 100 6/14 7/21 2 85 53 937
Camelina winter scatter 71 6/1 6/30 2 51 60 850
Camelina spring scatter 95 6/12 7/8 2 34 57 1147
Camelina spring machine 98 6/11 7/9 2 42 55 865
LSD (P<=0.05) 28 4 3 n.s. 36 15 312
C.V. (%) 27 22 15 50 32 17 28
z1 = no lodging; 10 = severe lodging.
yWeed pressure estimated by visual rating, with 100 = most weedy, 0 = least weedy.

Table 5. Influence of a cover crop on winter-sown camelina performance. Camelina was planted broadcast-sown in early December on either bare ground or on flax stubble sown in late August or early September; data from Robinson (1987).

Seed yield (kg/ha)
Treatment Stand (%) Maturity Weed control (%)z Lodging (%) 1971 1972 1973 Ave.
No cover crop 77 7/11 78 37 840 1243 1747 1277
Flax cover crop 89 7/9 83 18 1120 1176 1870 1389
LSD (P<=0.05) --- --- --- --- 157 146 146 90
zPercent of weeds controlled estimated by visual rating (100 = least weedy).

Table 6. Fatty acid composition of camelina compared with 5 other oilseeds, grown at Rosemount, Minnesota, 1991.

Fatty acid content (% of oil)
Fatty acid Canola Soybean Sunflower Crambe Flax Camelina
Palmitic (16:0) 6.19 10.44 6.05 2.41 5.12 7.80
Stearic (18:0) 0 3.95 3.83 0.40 4.56 2.96
Oleic (18:1) 61.33 27.17 17.36 18.36 24.27 16.77
Linoleic (18:2) 21.55 45.49 69.26 10.67 16.25 23.08
Linolenic (18:3) 6.55 7.16 0 5.09 45.12 31.20
Arachidic (20:0) 0 0 0 0.50 0 0
Eicosenoic (20:1) 0 0 0 2.56 0 11.99
Erucic (22:1) 0 0 0 54.00 0.88 2.80
Other FA 4.38 5.79 3.5 6.01 3.80 3.40

Fig. 1. Camelina plant nearing maturity. Camelina superficially resembles flax.


Fig. 2. Percent saturated and unsaturated fatty acids in camelina compared with other oilseeds grown at Rosemount, Minnesota, 1991. Unidentified fatty acids are those which did not match standards. Camelina is similar to soybean in balance of saturated vs. unsaturated fats, but is higher in C18:3 fatty acids.
Last update September 11, 1997 aw