E.A. Oelke1, D.H. Putnam1, T.M. Teynor2, and E.S. Oplinger3
1
Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108.Quinoa or quinua (Chenopodium quinoa Willd.) is native to the Andes Mountains of Bolivia, Chile, and Peru. This crop (pronounced KEEN-WAH), has been called 41 vegetable caviar" or Inca rice, and has been eaten continuously for 5,000 years by people who live on the mountain plateaus and in the valleys of Peru, Bolivia, Ecuador, and Chile. Quinua means "mother grain" in the Inca language. This crop was a staple food of the Inca people and remains an important food crop for their descendants, the Quechua and Aymara peoples who live in rural regions.
This annual species is in the goosefoot family and is related to the weed, common lambsquarters (Chenopodium album L.), canahua (C. pallidicaule Aellen), and wormseed (C. ambrosiodes L. anthelminticum). Possible hybrids between quinoa and common lambsquarters have been observed in Colorado. Quinoa is also in the same botanical family as sugarbeet, table beet, and spinach, and it is susceptible to many of the same insect and disease problems as these crops. Quinoa is sometimes referred to as a "pseudocereal" because it is a broadleaf non-legume that is grown for grain unlike most cereal grains which are grassy plants. It is similar in this respect to the pseudocereals buckwheat and amaranth.
Quinoa is a highly nutritious food. The nutritional quality of this crop has been compared to that of dried whole milk by the Food and Agriculture Organization (FAO) of the United Nations. The protein quality and quantity in quinoa seed is often superior to those of more common cereal grains (Table 1). Quinoa is higher in lysine than wheat, and the amino acid content of quinoa seed is considered well-balanced for human and animal nutrition, similar to that of casein (Table 2).
Quinoa is used to make flour, soup, breakfast cereal, and alcohol. Most quinoa sold in the United States has been sold as whole grain that is cooked separately as rice or in combination dishes such as pilaf. Quinoa flour works well as a starch extender when combined with wheat flour or grain, or corn meal, in making biscuits, bread, and processed food.
Seed coats (pericarp) are usually covered with bitter saponin compounds that must be removed before human consumption. Saponins may also be toxic to fish. Deresination (removal of the pericarp and the saponins by mechanical or chemical means) does not affect the mineral content of the seed (Johnson and Croissant, 1990). The marketable seed is usually white in color. The leaves are frequently eaten as a leafy vegetable, like spinach. Seed imported from growers in South America is sold in the United States in health-food stores and gourmet food shops at high prices.
Quinoa grain has a lower sodium content and is higher in calcium, phosphorus, magnesium, potassium, iron, copper, manganese, and zinc than wheat, barley, or corn (Table 3). The determination of the mineral content from Colorado quinoa trials showed a similar relationship, but differences from other grains were less conspicuous.
Table 1. Comparisons of the nutritional quality (% dry weight) of quinoa with various grains.
|
Crop |
% dry weight | |||||
|
Water |
Crude Protein |
Fat |
Carbohydrates |
Fiber |
Ash | |
|
Quinoa |
12.6 |
13.8 |
5.0 |
59.7 |
4.1 |
3.4 |
|
Barley |
9.0 |
14.7 |
1.1 |
67.8 |
2.0 |
5.5 |
|
Buckwheat |
10.7 |
18.5 |
4.9 |
43.5 |
18.2 |
4.2 |
|
Corn |
13.5 |
8.7 |
3.9 |
70.9 |
1.7 |
1.2 |
|
Millet (Pearl) |
11.0 |
11.9 |
4.0 |
68.6 |
2.0 |
2.0 |
|
Oat |
13.5 |
11.1 |
4.6 |
57.6 |
0.3 |
2.9 |
|
Rice |
11.0 |
7.3 |
0.4 |
80.4 |
0.4 |
0.5 |
|
Rye |
13.5 |
11.5 |
1.2 |
69.6 |
2.6 |
1.5 |
|
Wheat (HRW) |
10.9 |
13.0 |
1.6 |
70.0 |
2.7 |
1.8 |
Source for quinoa: Cardoza, A. and M. Tapia. 1979. Valor nutrivia. In: Quinoa y Kaniwa. M. Tapia (ed.), Serie Libros y Materiales Educativos No. 49. Reported by J. Risi and H. W. Galwey. 1994. Analyses of the remaining crops reported by: Crampton, E. W. and L.E. Harris. 1969. Applied Animal Nutrition, 2nd ed., W. H. Freeman and Co., San Francisco.
Table 2. Essential amino acid pattern of quinon compared to wheat, soy, skim milk, and the FAO reference pattern (1973) for evaluating proteins.
|
Amino Acid |
Amino Acid Content (g/100g protein) | |||||
|
Quinoa |
Wheat |
Soy |
Skim Milk |
FAO | ||
|
% | ||||||
|
Isoleucine |
4.0 |
3.8 |
4.7 |
5.6 |
4.0 | |
|
Leucine |
6.8 |
6.6 |
7.0 |
9.8 |
7.0 | |
|
Lysine |
5.1 |
2.5 |
6.3 |
8.2 |
5.5 | |
|
Phenylalanine |
4.6 |
4.5 |
4.6 |
4.8 |
- | |
|
Tyrosine |
3.8 |
3.0 |
3.6 |
5.0 |
- | |
|
Cystine |
2.4 |
2.2 |
1.4 |
0.9 |
- | |
|
Methionine |
2.2 |
1.7 |
1.4 |
2.6 |
- | |
|
Threonine |
3.7 |
2.9 |
3.9 |
4.6 |
4.0 | |
|
Tryptophan |
1.2 |
1.3 |
1.2 |
1.3 |
1.0 | |
|
Valine |
4.8 |
4.7 |
4.9 |
6.9 |
5.0 | |
Source: Johnson, R. and R. Aguilera. 1980. Processing Varieties of Oilseeds (Lupine and Quinoa), In: Report to Natural Fibers and Foods Commission of Texas, 1978-1980 (Reported by D. Cusack, 1984, The Ecologist 14:21-31).
Table 3. Comparisons of the mineral content In quinoa grain with barley, yellow corn, and wheat. Quinoa data are based on the average of 15 cultivars.
|
Crop |
Ca |
P |
Mg |
K |
Na |
Fe |
Cu |
Mn |
Zn |
|
% |
PPM | ||||||||
|
Quinoa |
0.19 |
0.47 |
0.26 |
0.87 |
115 |
205 |
67 |
128 |
50 |
|
Barley |
0.08 |
0.42 |
0.12 |
0.56 |
200 |
50 |
8 |
16 |
15 |
|
Corn |
0.07 |
0.36 |
0.14 |
0.39 |
900 |
21 |
- |
- |
- |
|
Wheat |
0.05 |
0.36 |
0.16 |
0.52 |
900 |
50 |
7 |
14 | |
Source: E. Ballon (1987), personal communication, reported by Johnson (1990).
Plants grow from 1 1/2 to 6 1/2 ft in height, and come in a range of colors that vary from white, yellow, and pink, to darker red, purple, and black. Quinoa has a thick, erect, woody stalk that may be branched or unbranched, and alternate, wide leaves that resemble the foot of a goose. Leaves on younger plants are usually green; but as the plant matures, they turn yellow, red, or purple. The root
system develops from a tap root to form a highly branched system that makes plants more resistant to drought. Varieties of quinoa mature in 90 to 125 days after planting in southern Colorado. Early-maturing varieties are recommended because of the short growing season at these high elevations.
Quinoa is usually self pollinated, but cross pollination does occur at rates of up to 10 to 15% (Risi and Galwey, 1989). Seed is produced in large clusters on a panicle that resembles that of sorghum. The seed is similar in size to millet (0.8 to 0.11 in. in diameter) and has two flat surfaces and rounded sides, which resembles an aspirin tablet. Seeds can be black, red, pink, orange, yellow, or white in color. The seed color is due to a resinous coating that contains two to six percent saponin. The embryo comprises 60% of the volume within the pericarp, and this results in the higher protein content of the seed in comparison to cereal grains.
Quinoa requires short daylengths and cool temperatures for good growth. Areas in South America where it is still produced tend to be marginal agricultural areas that are prone to drought and have soils with low fertility. Cultivated quinoa will flower and produce seed at high elevations between 7,000 and 10,000 ft in Colorado since it requires a cool temperature for good vegetative growth. Research conducted in Colorado reported that temperatures which exceeded 95°F tended to cause plant dormancy or pollen sterility. In several years of trials near the Twin Cities, Minnesota, quinoa plants have failed to set seed; probably due to high temperatures.
Quinoa plants are usually tolerant to light frosts (30° to 32°F). Plants should not be exposed to temperatures below 28°F to avoid the 70 to 80% loss that occurred in Colorado during 1985 when plants were in mid-bloom (Johnson and Croissant, 1990). However, plants are not affected by temperatures down to 20°F after the grain has reached the soft-dough stage. Quinoa will flower earlier when grown in areas with shorter daylengths.
Quinoa is generally not a widely adapted crop due to temperature sensitivity. Farmers should experiment first before planting large acreages.
This crop grows well on sandy-loam to loamy-sand soils. Marginal agricultural soils are frequently used in South America to grow quinoa. These soils have poor or excessive drainage, low natural fertility, or very acidic (pH of 4.8) to alkaline (8.5) conditions.
Quinoa prefers cool soil conditions (45° to 50°F). Germination occurs within 24 hours after planting when adequate moisture is present, and seedlings emerge in three to five days. Quinoa seeds, like those of spinach, may not germinate if conditions are warm and may need to be refrigerated for a week (vernalized) to obtain adequate germination.
Quinoa requires a level, well-drained seedbed in order to avoid waterlogging.
Robinson (1986) planted quinoa in mid-May at Rosemount, Minnesota that emerged about June 1, but earlier dates are also appropriate. Seed is planted in late April to mid -May in southern Colorado.
Seeds should be planted at a depth of 1/2 to 1 in. depending on soil type and available soil moisture. Ile small size of the seed makes it susceptible to both dehydration and waterlogging when planted too shallow, or deep, respectively. Row width can vary, but rows should be spaced by a minimum of 14 in. Varieties in Colorado have been grown in rows 20 to 30 in. apart. Stands of 130,000 plants/acre appear to be optimal for growing conditions in Colorado. A stand of this density would require 1/2 to 3/4 lb of seedlacre. Seeding rates are usually doubled when growing conditions are not optimal. Better stands are obtained when seed is planted in a moist soil, instead of irrigating after planting prior to emergence. Field trials in Great Britain indicated that increasing plant density resulted in a slightly earlier maturity, greater seed yield, and less -branching of plants.
Quinoa responds well to nitrogen fertilizer. In the first year of trials in Colorado, the variety Linares and others responded favorably to application of nitrogen fertilizer (Table 4). Research on nitrogen and phosphorus requirements conducted for three years by D. L. Johnson of Colorado State University found that maximum yields are possible when 150 to 180 lbs N/acre are available. Yields declined when greater levels of available nitrogen were present due to a slower maturity and more intense lodging. No effect on yield was observed when 30 lb of phosphorus (as phosphate acid) per acre was applied, in comparison to an untreated field plot.
Table 4. Effect of nitrogen on quinoa yields in Colorado during 1983 for the variety Linares1. Other varieties have responded In a similar fashion.
|
Nitrogen |
Yield |
|
15 |
950 |
|
65 |
991 |
|
125 |
1,378 |
1
Source: Johnson and Croissant (1990).This crop is somewhat drought tolerant with a water requirement of 10 to 15 in. per year (precipitation and irrigation combined on sandy-loam or loamy-sand soils). Studies on crop water use conducted during 1987 in Colorado found that the application of lower amounts of water reduced plant height by 50% with only an 18% reduction in yield. Crops planted during late April to mid-May in Colorado did not usually need irrigation until mid-June when the soil was near field capacity at planting time. Plants should not be irrigated until the two- or three-leaf stage. Rainfall in July has usually been sufficient during Colorado research trials to supply the crop until August. Excessive irrigation after stand establishment usually produces tall, lanky plants with no yield improvement. Damping off and severe stunting of plants will occur with excessive irrigation in the seedling stages.
The Agricultural Experiment Station at Colorado State University has developed a yellow-seeded variety, CO407, which is the only registered variety that is available (Table 5). This variety was derived from plants that came from Chile and was released in 1987. 'CO407' typically has a short height, early maturity (100 days after planting), compact seed head, and resists grain shattering. This variety has a rich, nutty flavor and 16.5 to 18% protein, which is higher than other types that have averaged 12.5 to 14%. The nutty flavor of the flour made from this variety complements those of other grain flours when it comprises as little as 15 to 30% of a product. The pericarp with its coating of saponins is removed effectively by abrasion rather than washing. Three other varieties, CO409, Cahuil, and CO407 Black, have good yield potential based on field performance in southern Colorado.
Weed control in quinoa fields is difficult since plants grow slowly during the first two weeks after emergence. In commercial fields of southern Colorado, pigweed, kochia, lambsquarters, and sunflower have been the most common weeds. Wild mustard and sunflower can be a problem since it is not possible to separate them from quinoa seed. There are no registered herbicides for quinoa at this time. Preemergence herbicide trials have been conducted in field and greenhouse locations in Colorado. Several herbicides were used safely on quinoa, but were variable in weed control.
Competition from weeds is greater when quinoa is planted later in the growing season. Kochia and lambsquarters numbers can be reduced when field irrigation is followed by cultivation before seeding. Pigweed emerges too late in the growing season to depend on cultivation for weed control. Early planting may be the most effective means to control pigweed since the quinoa will have a good start in growth before the pigweed emerges.
Disease and pest problems may arise after a crop like quinoa is introduced to a new production area. Viruses found on spinach or beets have been observed in quinoa fields. Many of these viruses are transmitted by aphids or leafhoppers. Several of the viruses tested produce symptoms, yet research needs to be conducted to determine if any cause significant damage. Diseases such as damping off (Sclerotium rolfsii), downy mildew (Peronospora farinosa), stalk rot (Phoma exigua var. foveata), leaf spot (Ascochyta hyalospora), grey mold (Botrytis cinerea), and bacterial blight (Pseudomonas sp.) have also caused significant losses in South America, North America, and Great Britain.
A wide variety of insect pests can damage quinoa during seed germination up through harvest and seed storage in production areas of South America. Insect pests observed in North America include flea beetles and a wide variety of caterpillars (insect larvae). Flea beetles and aphids caused damage in quinoa trials conducted in Minnesota (Robinson, 1986). The sugarbeet root aphid (Pemphigus populivenae) has significantly reduced yields in isolated research fields of Colorado. Since this crop requires little water, the soil will crack and allow aphids access to the roots. There are no pesticides cleared for use on quinoa. The best control method for this aphid is to irrigate fields when winged forms appear in leaf-petiole galls of cottonwoods and poplars (overwintering habit) in early summer. The "quinoa plant bug" (Melanotrichus sp.) and the beet armyworm (Spodoptera exigua) have also reduced yields in some research fields. Bacillus thuringiensis, a naturally occurring bacterium that controls certain insect larvae, can be used to control the defoliating caterpillars. Entomologists at Colorado State University, do not consider insect problems to be a yield-limiting factor for quinoa production at this time.
Seed in the panicle is subject to feeding losses by birds. Quinoa, like some other grains, evolved a chemical defense against the feeding activity of insects and animals with the production of bitter saponins in the pericarp. However, saponins are easily washed out by rain and may not totally prevent feeding losses.
Plants have a sorghum-like seed head at maturity. Harvest usually begins when the seed can barely be dented with a fingernail and plants have dried, turned a pale yellow or red color, and leaves have dropped. The seed should thresh easily by hand at this time. Field dry down is usually acceptable and plants are harvested easily with a combine. A sorghum header attachment is recommended for quinoa, although platform headers can usually be used as well, without a large crop loss. Cylinder speed and air flow of combines are usually greatly reduced. Smaller screens are used than with cereal grains due to the small size and lighter weight of quinoa seed. A fanning mill and gravity separator is usually necessary to remove trash from the seed after combining. Grain must be dry before storage. Quinoa stover contains little fiber and subsequently provides little crop residue.
Rain during harvest will cause problems since mature seed will germinate within 24 hours after exposure to moisture.
The seed must remain dry during storage. Prior to using quinoa in food processing, the saponins in the pericarp are removed by soaking them in water or by mechanical methods, such as with a rice polisher or a machine similar to those used to remove wheat bran.
Most quinoa used in North America is imported from South America. Research on developing quinoa as a crop for North American agriculture is being conducted in Colorado. The first commercial crop was produced in Colorado in 1987. Average yields were about 1,000 lb/acre, produced on fields that ranged from 10 to 80 acres in size. The variety CO407 has given consistent yields of 1,200 lb/acre in Colorado field trials, while other lines have yielded from 1,421 to 1,739 lb/acre (Table 5). Yields that exceed 1,800 lb/acre in research trials are possible with adequate stands, fertility, moisture, and weed control. This crop has the potential to be produced on 6,000 acres in Colorado at elevations above 7,000 ft (Robinson, 1986). Quinoa planted by Robinson in Minnesota grew about two feet tall but did not flower and produce seed, as high summer temperatures probably caused the plants to become dormant. Quinoa lines grown in 1991 at Rosemont also did not set seed (Putnam, D.H., pers. com.).
Table 5. Performance of selected quinoa varieties in research trials conducted during 1987 in south central Colorado1.
|
Landraces/Lines |
Yield |
Panicle color |
Plant height |
|
Cahuil |
1,739.8 |
mixture |
4.3 |
|
C0407-78 |
1,692.3 |
yellow |
4.3 |
|
C0407-06 |
1,690.6 |
yellow |
5.9 |
|
C0407-260 |
1,6903 |
yellow |
4.6 |
|
Milahue |
1,634.6 |
red, white |
6.9 |
|
Isluga |
1,499.0 |
mixture |
5.6 |
|
Faro |
1,421.6 |
mixture |
6.6 |
|
CO407 |
1,206.2 |
mixture |
4.3 |
1
Source: Johnson and McCamant (1988), Johnson and Croissant (1990).Quinoa should be considered a future crop for most North American farmers. This crop is not recommended for growers except on an experimental basis in Minnesota or Wisconsin at this time, since there are no varieties that will produce well under the environmental conditions in these areas. Hot summer temperatures, precipitation greater than 10 to 15 in. per year, and wet conditions during seed maturation, prevent growing the available varieties in the Upper Midwest. Areas located in southern Colorado and northern New Mexico at an elevation of 7,000 ft, northward from central California along the Pacific Coast, the eastern side of the Cascade Mountains., in northern Washington, and locations in the Canadian;' Prairie provinces (especially Saskatchewan) at 2,000 to 3,000 ft, may be the best production areas in the future.
The current market for quinoa in North America is limited. A widespread effort is necessary to educate people in the United States about what quinoa is and how to cook it before the market will expand a great deal. Five farms in Colorado started to grow quinoa as a commercial crop in 1987 after a processing facility was provided by the Pillsbury Company to remove saponins from the pericarp. The North American Quinoa Producers Association was organized in 1988 and a small processing plant was started for the crop produced in Colorado. Costs of production for Colorado growers decreased from $1.00/lb in 1984 to $0.35/lb in 1987 as they became more familiar with the crop and obtained higher yields (Johnson, 1990). Prices to producers have currently (1991) ranged from S.80/lb to over $1.00 lb.
In the United States this crop has been available in health food stores and more recently (1988), in grocery stores of the western United States for prices that range from $2.50 to $3.40/lb. The high nutritional quality, good flavor, and many uses in food products, give quinoa a good potential market. The market for quinoa has continued to grow in North America since 1984, yet the acreage planted has declined since 1985 due to crop losses from adverse environmental conditions such as insect, disease, and weed problems. Prospective growers from areas with suitable environmental conditions should contact a marketing group about contracts for quinoa seed before raising the crop. The quinoa market in 1987 for the United States was approximately 500,000 lbs.
The food industry is ready to make quinoa products due to the current market and its good growth potential. These companies have a disincentive to make quinoa products until the cultural problems have been reduced and yields have improved so there is a larger, more reliable supply available to processors. Future varieties will have a white pericarp (low or no saponin content), grow well at lower elevations, and have better yield, plant height and form, seed size, and resistance to pest, disease, and other environmental factors. A low saponin content would avoid some processing costs, a larger seed would reduce the proportion of fibrous pericarp in the grain, and a white pericarp would give a colorless, versatile product for the food processing industry. However, the elimination of saponins in future varieties may also increase feeding losses by birds and other pests.
The information given in this publication is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no endorsement for one product over similar products is implied by the Minnesota and Wisconsin Extension Services.