Cajema meyer

Overview

Derived from the Spanish spelling of the Quechua name kinwa or occasionally "Qin-wah", Quinoa originated in the Andean region of South America, where it was successfuly domesticated 3000 to 4000 years ago for human consumption, though archeological evidence shows a non-domesticated association with pastoral herding some 5200 to 7000 years ago.[1]
Similar Chenopodium species, such as pitseed goosefoot (Chenopodium berlandieri) and fat hen (Chenopodium album), were grown and domesticated in North America as part of the Eastern Agricultural Complex before maize agriculture became popular.[citation needed] Fat hen, which has a widespread distribution in the Northern Hemisphere, produces edible seeds and greens much like quinoa, but in lower quantities.
The nutrient composition is very favourably compared with common cereals. Quinoa grains contain essential amino acids like lysine and good quantities of calcium, phosphorus, and iron. After harvest, the grains need to be processed, in order to remove the coating containing bitter-tasting saponins.
Quinoa grains are in general cooked the same way as rice and can be used in a wide range of dishes. Quinoa leaves are also eaten as a leaf vegetable, much like amaranth, but the commercial availability of quinoa greens is currently limited.

Biology

Quinoa is a dicotelydoneous, annual plant usually about 1-2 m high. It has broad, generally pubescent, powdery, smooth (rarely) to lobed leafs normally arranged alternately. The woody central stem is either branched or unbranched depending of the variety and may be green, red or purple. The panicles arise either from the top of the plant or from axils on the stem. The panicles have a central axis from which a secondary axis emerges either with flowers (amaranthiform), or bearing a tertiary axis carrying the flowers (glomeruliform). The green, hypogynous flowers have a simple perianth and are generally bisexual and self-fertilizing. The fruits are about 2 mm in diameter and of various colours - from white to red or black depending on the cultivar.

Cultivation

Climate requirements

Quinoa is highly variable due to a high complexity of different subspecies, varieties and landraces. However, in general it is undemanding and altitude-hardy. It is grown from coastal regions (Chile) to over 4000 m (13,120 ft) in the Andes near the equator. However, most of the cultivars are grown between 2500 m and 4000 m. Depending on the variety, Quinoa's optimal growing conditions are in cool climates with temperatures that range from 25°F/-3°C, during the night, to below 95°F/35°C, during the day. Some cultivars can also withstand lower temperatures without damage. Light frosts normally don’t affect the plants at any stage of development except during flowering. Mid-summer frosts often occurring in the Andes during flowering led to sterilization of the pollen. Rainfall conditions are highly variable between the different cultivars, ranging from 300 to 1000 mm during growing season. Optimal for Quinoa growth is well-distributed rainfall during early growth and development and dry conditions during seed maturation and harvesting.

Soil requirements

Quinoa does best in sandy, well-drained soils with a low nutrient content, moderate salinity and a soil condition of 6 pH to 8.5 pH.

Agronomy

Sowing

The seedbed must be well prepared and drained to avoid waterlogging. Normally in the Andes, Quinoa seeds are broadcast over land and raked into the soil. Sometimes it is sown in narrow, shallow soils.

Cultivation management

Yields are maximised when 150 to 180 lbs N/acre are available. The addition of phosphorus does not improve yield. In eastern North America, it is susceptible to a leaf miner that may reduce crop success; this leaf miner also affects the common weed and close relative ''Chenopodium album'', but C. album is much more resistant.

Harvesting and Handling

Harvesting is usually up until now mainly done by hand and rarely by machine, because of the extremely variable periods of maturity of native Quinoas which increases difficulty of mechanization. So, an exact timing of harvest is important in order to avoid a high loss of grains due to shattering. However, the exact harvesting time is difficult to determine because panicles of the same plant mature at different times. The grain yield reaches comparable dimensions (often around 3 t/ha up to 5 t/ha) to wheat yields in the Andean areas. Handling involves threshing the seedheads and winnowing the seed to remove the husk. Before storage, the seeds need to be dried in order to avoid germination.