Amaranth can be used as a high-protein grain or as a leafy
vegetable. The seeds are eaten as a cereal grain. They are ground into flour,
popped like popcorn or cooked into porridge. The seeds can be germinated into nutritious
sprouts.
The leaves are cooked alone or combined with other local vegetables
such as spider plant and pumpkins. The leaves are rich in calcium, iron and
vitamins A, B and C, but fairly low in carbohydrates. There is no distinct
separation between the vegetable and grain type since the leaves of young grain
type plants can be eaten as greens.
1. Varieties
Of all the indigenous tropical leafy vegetables, amaranth has the
largest number of species and varieties. The choice of variety varies widely among
regions and is dictated largely by the species available. Regardless of
species, the choice of variety is influenced by individual preference for leaf
colour and taste. Some of the most common commercial amaranths are selections
of A. tricolour which come in various leaf colours such as white (light green),
dark green, red, purple and variegated. To identify which varieties are best
adapted to your location, compare during different growing seasons the yield
potential of currently grown varieties with that of other available varieties.
2. Reproduction
and planting
Amaranth requires thorough land preparation and a well-prepared bed
for good growth. Form 20cm high beds during the dry season and 30cm during the
wet season using a plough. The distance between centres of adjacent furrows
should be about 150cm with a 90cm bed top.
Amaranth is planted either by direct seeding or transplanting. The
choice of planting method depends on availability of seed and labour and may
also vary with the growing season. Direct seeding is appropriate when plenty of
seed is available, labour is limited, and during the dry season when frequency
of flooding is less. Transplanting is preferred when there is limited amount of
seed, plenty of labour, and during the wet season when heavy rains and flooding
are most likely to wash out seeds. Raising seedlings in a nursery and
transplanting them to the field shorten the crop duration in the field, and
secure a better and more uniform stand especially during the wet season.
3. Climatic conditions
suitable for amaranth, soil and water management
Amaranth grows from sea level to 2400m altitude. The different species may suit different altitudes. Normally the hotter it is the better it grows and it generally thrives within a temperature range of 22 to 30°C. A minimum temperature of 15 to 17°C is needed for seed germination. Amaranth is grown during both wet and dry seasons, though irrigation is normally required for dry season crops since the rate of transpiration by the leaves is fairly high. Frequent applications of water are required, related to the stage of growth of the crop and the moisture-retaining capacity of the soil. It can however tolerate periods of drought after the plant has become established. It is adapted to low to medium humidity. Amaranth grows best in loam or silty-loam soils with good water-holding capacity, but it can grow on a wide range of soil types and soil moisture levels.
4. Managing amaranth
Amaranth is a low management crop and can grow in poor soils, but it
will benefit from application of organic fertiliser resulting in yield
increases.
Although amaranth is relatively drought tolerant, yet insufficient
water will reduce yield. Water should be applied especially just after sowing
or transplanting to ensure a good stand. As a rule, the plants should be
irrigated if wilting occurs at noontime. Another way to estimate soil moisture
content is to take a handful of soil from the bottom of a 15cm deep hole.
Squeeze the soil. If it holds together when you release your grip, there is
sufficient soil moisture; if the soil crumbles, it is time to irrigate.
Irrigate thoroughly to maintain vigorous plant growth. Avoid over-irrigation,
which may enhance disease development and nutrient leaching. Drip irrigation or
micro-sprinkler irrigation is recommended in areas with limited water supply.
(AVRDC 2003)
5. Harvesting amaranth
First harvest is at a plant height of 30cm, about 6 weeks after
transplanting. Plants may be harvested at once or leaves and tender shoots
maybe harvested several times. One single harvesting is adapted for short
maturing and quick growing varieties such as A. tricolour. Whole plants are
pulled from soil with roots, washed and tied in bundles. With multiple
harvests, young leaves and tender shoots are picked at 2 to 3 week intervals.
Eventually, the plants begin to flower and develop fewer leaves. Frequent
harvesting of leaves and shoots delays the onset of flowering and thus prolongs
the harvest period.
Amaranth and other leafy vegetables have a large surface and loose
water rapidly. To reduce water loss, harvest during the cooler time of day,
such as early morning or late afternoon.
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