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Bởi: Dr. Thomas Post
Phát hành: 01-04-2009

AN 1 - Amaranth Potential for the Highlands of Southeast Asia - Figure 1This article is from ECHO Asia Note #1

Potential of Amaranth in the Highlands of Southeast Asia

Based on the experiences of CRWRC and its collaborating partnering organizations in East Africa, the introduction of grain and vegetable amaranths shows real potential for the highlands of Southeast Asia. Grain amaranth should be seen and managed as a high protein nutritional supplementary crop to compliment the Southeast Asian staple crop of rice. Given the high incidence of malnutrition in some of the upland rice-dominant areas of Southeast Asia (e.g., close to 50% stunting among children in northeastern Laos), having the nutritional supplement of even a small amount of grain amaranth in the daily diet could be a great help. For example, a study in Mexico found that as little as 20 grams of ground amaranth flour per day per child (approximately 2 tablespoons) made a significant difference in child growth.

The fact that grain amaranth is highly drought resistant, once established, means that it has potential as a relay or sole crop that could be grown towards the end of the rainy season in Southeast Asia and thereby extend the productivity of the growing season. However, successful adoption for self consumption by farmers will likely require methodical training and support to both men and women in the farm family. This is due to its photoperiodic sensitivity (i.e. flowering is triggered by shortening day lengths), the fact that the tastes/cooking methods of the leaves (but not of the grain) are known to people, and to farmers' lack of knowledge about the best methods for growing the grain types. On the other hand, a big advantage for grain amaranth adoption is that the taste of the grain is fairly neutral, slightly nutty, and mixes well with other grains, including rice. At the same time the open in browser PRO version Are you a developer? Try out the HTML to PDF API pdfcrowd.com and mixes well with other grains, including rice. At the same time the consumption of amaranth leaves-from either grain varieties or vegetable varieties is likely to occur more rapidly than grain consumption. Although this will have a favorable nutritional impact it will not be as great as the consumption of the grain.

Grain amaranth's nutritional impact derives from its high protein content (about 12 to 16% total protein), a superior balance of essential amino acids within the protein (especially a high level of lysine, which is low in cereal crops) and its high content of vitamins, calcium and fat. Maximum nutritional benefit from eating the grain comes when it is first popped and then cooked simultaneously with a staple grain such as rice or maize at ratios between 1 part grain amaranth to 3 to 5 parts of the staple grain. Most families in East Africa have simply been grinding the grain amaranth and then cooking it with maize flour using the above ratios.

[Editor: Ray Heinecke, a retired food scientist who has studied grain amaranth, explains that popping amaranth is preferred over using whole grains for mixing with lower nutritional quality grains (e.g., rice, maize). This is because popping results in a more complete protein mixture as the grain's starch becomes completely gelatinized. Dr. Heinecke explains,"Because amaranth is such a small and tightly bound seed, complete gelatinization of raw seeds may take longer than the normal cooking process would allow. Without complete gelatinization the starch is less digestible and may cause faster transit times in the GI (gastrointestinal) track rendering everything else less digestible."

Dr. Heinecke adds that if popping is not possible, using ground amaranth is almost as good since the grinding process greatly increases the surface area of the starch particles. In some cases grinding can also break the starch particles down. Therefore, starch could be completely gelatinized after the ground grain amaranth has been cooked for 30 minutes or longer.]

Leaves can be prepared according to local cooking customs for other leaves. However, it is better to grow one plot of amaranth for leaves open in browser PRO version Are you a developer? Try out the HTML to PDF API pdfcrowd.com and another for grain, so that the grain yield is not harmed by the removal of leaves.

Southeast Asian planting dates for grain amaranth must take several factors into account:

  • The grain amaranth varieties flower and seed in response to the shortening days preceding December 21 in regions north of the equator-this includes most of SE Asia. The grain types take about 75 days to harvest.
  • Grain amaranth seeds germinate best in warm soil (requiring fairly warm night temperatures) and grow best in warm dry air with sufficient soil moisture.
  • Once the tap roots are established (after about 3 weeks), the plants are very drought resistant.
  • The monsoonal rains in Southeast Asia (i.e., Northern Hemisphere) diminish during November and December and generally cease by January, with day and night temperatures also cooling.

AN 1 - Amaranth Potential for the Highlands of Southeast Asia - Figure 2Planting Date Recommendation

Aim to plant grain amaranth about one month before the ending of reliable rains, so that the harvest will occur at least 2 to 4 weeks after the rains have stopped. Generally, north of the equator, this will mean planting sometime during the months of September or October for the highland areas of Southeast Asia. However, plantings for producing amaranth leaves can occur at any time that there is sufficient soil moisture.

Other Considerations

Small seeds, thinning and row width: Grain amaranth seeds are very small. This means that when a farmer directly plants the seeds, he will probably end up with too many plants. He will have to thin the plants usually twice (but his family can eat the leaves of these plants) in order to have about one plant per 15 cm in the rows. If the plants are too crowded, they will all be small and skinny and will produce very little seed. A row width of 60 cm seems to help keep the plants from growing too tall and then falling over in strong winds. To reduce the amount of thinning that is needed, at planting time grain amaranth seed can be mixed with dry sand at a ratio of 1:15.

Insect pests: Trials in Chiang Mai, Thailand, showed that lygus bugs attacked grain amaranth flowering heads. However, lygus bugs can be controlled with low-toxicity pesticides and possibly with botanically derived insecticide. Stem borers were also a problem in some trials.

Seed availability: Dr. Chuckree Senthong, at Chiang Mai University, selected best-adapted types of grain amaranth during trials in the 1980s. He is beginning to multiply the most promising of these varieties. Limited seed availability will restrain grain amaranth trials by farmers at this point, unless seed is imported from East Africa.

Lessons from CRWRC's Experiences in East Africa

Development workers who are considering the promotion of amaranth as a new crop in Asia might be interested in the following lessons learned from 10 years of CRWRC efforts in East Africa:

  • A crop that is not known by farmers requires much teaching and follow up time. CRWRC learned that using a volunteer farmer-nutritionist couple helped a lot!
  • Start the teaching by letting people taste the new crop first! (1 part to 3 parts, 1:4 or 1:5 mix ratio of grain amaranth to the local staple). Teach people to use 2 to 3 tablespoons per day per child and about 4 tablespoons per day per adult if they are using the ground grain amaranth flour.
  • Organizing "demonstration eating days" has increased home amaranth consumption. 
  • Amaranth mixes well with many traditional foods, which helps acceptance.
  • Start by growing grain amaranth for food; don't promise that you will provide a cash crop market.
  • Don't assume you already have the best varieties. Varieties differ in photoperiod response, taste and production.
  • Often HIV+ adults report improvements in their health when they eat amaranth. Frequently malnourished children show weight gains, too.
  • People eat and sell both leaves and grain.
  • Amaranth's drought resistance has been demonstrated by farmers.
  • Semi-arid farmers can achieve harvests of amaranth even when maize fails.

Nutritional, Health and Farm Benefits Reported From Amaranth in East Africa

  • Mothers report that children are brighter in school, i.e., they are more alert after nutritious meals.
  • Sequential visits show children having shinier skin and less dryness and flaking on their arms.
  • Children under 5 years of age grow normally once they eat amaranth every day. Because of the tremendous results in the communities, nurses in the clinics advise mothers with malnourished, underweight children to feed them amaranth.
  • Health workers and mothers have told us on several occasions that there is less anemia among mothers (amaranth is high in iron).
  • We also heard from mothers who did not have enough breast milk that milk production increased tremendously.
  • HIV+ people say that now the ARV drugs don't make them feel ill.
  • We have heard on many occasions that HIV+ people who consume grain amaranth have an increase by several hundred points in their CD-4 count. They are able to start the ARV drugs after the CD count is up to at least 600.
  • We heard that people suffering with arthritis and hip problems felt much better after consuming amaranth.
  • Children are brighter in school! Adults are stronger.
  • Grain amaranth is also helpful for diabetics where dietary balance is key.
  • People have told us that cows who consume the amaranth stalks give more milk
  • People have told us on numerous occasions that when chickens eat the amaranth chaff, egg production doubles and the shells are harder.
  • Amaranth is now in demand in the market, with millers buying. In Kampala, Uganda, amaranth is substituted for the soyderived lysine supplement in refined maize meal that was formerly imported from South Africa. In Kenya, three millers are now buying grain amaranth, and amaranth flour is available in supermarkets.
  • Many families are adopting amaranth cultivation and use.

AN 1 - Amaranth Potential for the Highlands of Southeast Asia - Figure 3Extension Steps Used in East Africa

  • Show the video: The CRWRC grain amaranth video is shown on a laptop computer to the staff of partnering organizations in their regional offices.
  • Give a nutritional talk: Nutritional talks are given in villages, during which amaranth stories are shared by other villagers. If possible, facilitate exchange visits between new villages and experienced villages. Also, if possible, invite Ministry of Agriculture staff.
  • Make sure women are invited: Learning to cook amaranth is crucial!
  • Stress these points:
    • Nutritional benefits should be stressed first (e.g., crowd.com brighter children, dietary balance for diabetics).
    • Benefits for those living with AIDs should be stressed secondly: we learned that if this benefit was mentioned first, it caused a stigma against growing grain amaranth.
    • Stress proper mixing ratio for whole grain amaranth with staple grain.
  • Plant two demonstration plots, one for eating leaves and one for eating grain.
  • Make sure plots are visible: Choose a demonstration spot at a clinic, school, or church, where people can easily watch and learn.
  • Homestead plots: Choose a spot within the 10 meters of the home site where the fertility is high and the family can easily observe.
  • Be timely about planting: For East Africa, planting was encouraged as soon as rains started, as the region has short rainy seasons (very different from Southeast Asia). Timely thinning and weeding also bring best results.
  • Multiply seed: Teach farmers how to harvest the strongest and healthiest plants first and save the seed for future planting.
  • Eat Amaranth food together!

Follow Up is Crucial!

  • In East Africa, two follow up visits per growing season were needed. The first occurred approximately four weeks into the growing season. We encouraged the partner organization's field workers to revisit at the first and second thinning and then again at harvest.
  • Farmer-to-farmer and staff-to-staff exchange visits have proven effective.
  • Hospital demonstrations and gardens have proven effective; hospital staff members have become promoters as a result.

[Editor: In addition to extensive experience in promoting grain amaranth in East Africa, Tom Post has also conducted informal grain amaranth field trials in Chiang Mai, Thailand. For questions related to the promotion of grain amaranth, Tom can be contacted at postt@crcna.org.  Additionally, Dr. Chuckree Senthong is continuing grain amaranth variety trails at Chiang Mai University. He can be reached at agicsnth@chiangmai.ac.th.

For more information about grain amaranth, readers may refer to EDN Issue 91 (April 2006) EDN Issue 91] References Ray Heinicke, e-mail message to the editor, March 27, 2009.