Panicum miliaceum (PROTA)
 |
Introduction |
| General importance |  
|
| Geographic coverage Africa |
|
| Geographic coverage World |
|
| Cereal / pulse |
|
| Medicinal |
|
| Forage / feed |
|
| Fibre |
|
| Food security |
|
| Climate change |
|
- Protologue: Sp. pl. 1: 58 (1753).
- Family: Poaceae (Gramineae)
- Chromosome number: 2n = 36
Vernacular names
- Proso millet, common millet, hog millet (En).
- Millet commun, kibi (Fr).
- Milho miúdo, milho de canario (Po).
Origin and geographic distribution
Proso millet is of ancient cultivation. Its origin has not been ascertained, but it was probably domesticated in central and eastern Asia, where it has been cultivated for more than 5000 years. Proso millet has long been a major crop in northern China. In the Bronze Age it spread widely in Europe, also to northern regions where the cold-susceptible foxtail millet (Setaria italica (L.) P.Beauv.) could not be grown. In Europe remains have been found in agricultural settlements dating back about 3000 years. Proso millet was the ‘milium’ of the Romans and the true millet of history. It was introduced into North America after the arrival of Columbus. In Europe and the United States its popularity as a cereal declined after the large-scale introduction of potato and maize.
Nowadays proso millet is cultivated for human consumption mainly in eastern and central Asia, and to a lesser extent in eastern Europe (Russia, Danube region) and from western Asia to Pakistan and India (Bihar, Andhra Pradesh). It is occasionally grown in other parts of Europe and Asia and in North America, mainly as a source of feed for cage-birds and poultry, and as fodder. In tropical Africa, it is cultivated in Ethiopia, eastern Kenya, Malawi, Botswana, Zimbabwe and Madagascar. It is also recorded from Lesotho. Its importance in Kenya is said to have declined since the 1950s following the advance of maize cultivation. Proso millet has widely naturalized, and is sometimes a troublesome weed, e.g. in the United States and Russia.
Uses
The husked grains of proso millet are eaten whole, boiled like rice or after roasting. They are also cooked into porridge, or, after grinding, baked into flat bread or chapatti. Only the flour of gluten-rich types can be used for leavened bread and cakes; the flour of other types has to be mixed with wheat flour. In China, where proso millet flour is made into bread, cultivars with glutinous (waxy) endosperm are favoured; in Mongolia, where the grains are cooked like rice, non-glutinous cultivars are grown. In Ethiopia, the grains are fermented into a kind of beverage (‘tella’). Elsewhere they are used for making beer and brandy. The grain is a feed for animals, including pigs, fowls and cage-birds. The plant is used as a forage. The forage quality of the straw is poor, and in India it is more often used for bedding for cattle. The straw is also made into brooms. Starch from the grains has been used for sizing textiles. Various medicinal uses of proso millet have been recorded in Asia; the seeds are used as a demulcent and as a treatment for abscesses and boils, and stem and root decoctions are taken against haematuria.
Production and international trade
Production statistics for proso millet are scarce because they are usually lumped with those of other millets. The average annual world production of proso millet in 1981–1985 was estimated at 4.9 million t, with the Soviet Union (2.3 million t), China (1.6 million t) and India (0.5 million t) as main producers. The annual production in 1992–1994 was estimated at 4 million t. In tropical Africa the production of proso millet is very low compared to that of pearl millet (Pennisetum glaucum (L.) R.Br.) and finger millet (Eleusine coracana (L.) Gaertn.), but no statistics are available.
Compared to the total world trade in cereals, the international trade in millets is insignificant. The world millet trade in 1999–2003 amounted to about 250,000 t/year. The share of proso millet of the total recorded millet trade has been estimated at about two-thirds. Most proso millet traded internationally is imported by the pet-food industry in industrialized countries for use as bird feed. As millet yields are relatively low, prices on the world market are generally higher than those of other cereals; the small size of the international millet trade results in volatile prices.
Properties
Proso millet contains per 100 g edible portion: water 8.6 g, energy 1582 kJ (378 kcal), protein 11.0 g, fat 4.2 g, carbohydrate 72.9 g, dietary fibre 8.5 g, Ca 8 mg, Mg 114 mg, P 285 mg, Fe 3.0 mg, Zn 1.7 mg, vitamin A 0 IU, thiamin 0.42 mg, riboflavin 0.29 mg, niacin 4.7 mg, vitamin B6 0.38 mg, folate 85 μg, ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 119 mg, lysine 212 mg, methionine 221 mg, phenylalanine 580 mg, threonine 353 mg, valine 578 mg, leucine 1400 mg and isoleucine 465 mg. The principal fatty acids are (per 100 g edible portion): linoleic acid 2015 mg, oleic acid 739 mg, palmitic acid 528 mg, stearic acid 145 mg and linolenic acid 118 mg (USDA, 2004). The grains have a relatively high indigestible fibre content because the seeds are enclosed in hulls which are difficult to remove by conventional milling processes. The husked grain of proso millet has a slightly nutty flavour.
Non-glutinous proso millet cultivars are considered suitable for the diet of people with coeliac disease. Experiments with rats indicate that proso millet protein may be useful as a preventive food for certain types of hepatitis. Proso millet has been found to induce allergic reactions in bird keepers.
Description
- Erect annual grass up to 1.2(–1.5) m tall, usually free-tillering and tufted, with a rather shallow root system; stem cylindrical, simple or sparingly branched, glabrous to variously hairy.
- Leaves alternate, simple; leaf sheath variously hairy; ligule membranous, c. 1 mm long, ciliate; blade linear-lanceolate, 10–42 cm × 0.5–2.5 cm, variously hairy, with 3–6 veins on each side of the midrib.
- Inflorescence a slender panicle 10–30(–45) cm × 5–15 cm, open or compact, erect or drooping.
- Spikelets solitary, stalked, ovoid-ellipsoid, 4–6 mm long, 2-flowered, glabrous; glumes unequal, the upper as long as spikelet, many-veined; lower floret sterile, upper one bisexual with thick broad (c. 2 mm) lemma and palea, 2 lodicules, 3 stamens and superior ovary with 2 plumose stigmas.
- Fruit a caryopsis (grain), broadly ovoid, up to 3 mm × 2 mm, smooth, variously coloured but often white, enclosed by the persistent lemma and palea and shedding easily.
Other botanical information
Panicum is a large genus comprising about 470 species and is mainly distributed in tropical and subtropical regions, with some species extending to temperate regions. Panicum miliaceum is a complex species with wild and cultivated types. In the literature the following two groups have been classified as subspecies: subsp. ruderale (Kitag.) Tzvelev including all spontaneous types, wild and weedy, and subsp. miliaceum comprising the cultivated types. The cultivated types have sometimes been classified into a cultivar group: Proso Millet Group. The wild types have lax panicles, usually jointed spikelet stalks and narrow lemmas, whereas the cultivated ones have either lax or compressed panicles, spikelet stalks without joints and wider lemmas. The true wild type is native to central China and is considered to be the ancestor of the cultivated types. In temperate regions of Europe, Asia and the United States, however, wild types occur that differ from the wild type in China and are most probably derivatives of cultivated types which have regained the ability of natural seed dispersal and spread as weeds.
Cultivated proso millet comprises many cultivars and landraces, and 5 groups have been distinguished, mainly based on size and shape of the inflorescences. Within these groups, cultivars are mainly distinguished on the basis of grain colour (varying largely from white, yellow, brown, red, to almost black) and ecological adaptation.
Growth and development
Proso millet matures in 45–90 days. Emergence of the seedling is usually in 4–8 days after sowing. During the vegetative phase, which is usually completed 16–20 days after sowing, tillering occurs and the inflorescence primordia are initiated. From then it takes 20–25 days to flowering of the main culm, but this period is somewhat shorter at higher temperatures. It is accompanied by an increase in leaf area and rapid elongation of stem internodes. The leaf number on the main culm differs among cultivars, but each cultivar produces a fixed number of leaves before flowering. Flowering proceeds from top to bottom. The flowers are normally self-fertilized, but cross-fertilization frequently exceeds 10%. The period from flowering to grain maturity has a duration of about 20–30 days, and is almost constant among cultivars. At grain maturity the lower part of the inflorescence as well as the stem and leaves are still green. Proso millet follows the C4-cycle photosynthetic pathway.
Ecology
Although proso millet is primarily a crop of temperate regions, it has a wide adaptability and can be grown in climates which are too hot and dry, and on soils which are too shallow and poor for successful cultivation of other cereals. It is cultivated further north than any other millet, the limit being the June isotherm of 17°C and the July isotherm of 20°C. Cultivation as a grain crop occurs up to 3000 m altitude in the Himalayas. It susceptible to frost. Proso millet has one of the lowest water requirements of all cereals. An average annual rainfall of 200–450 mm is sufficient, of which 35–40% should fall during the growing period. Most soils are suitable for proso millet, except coarse sand.
Propagation and planting
Proso millet is propagated by seed. The 1000-seed weight is (4.7–)5(–7.2) g. Proso millet seeds germinate well at temperatures of 10–45°C, with the highest rate at temperatures between 35°C and 40°C. The seed is either broadcast or drilled in rows 20–25 cm apart and at a distance of 7.5 cm in the row. This corresponds with a seed rate of 8–12 kg/ha. The recommended seed rate for furrow planting in Kenya is 4 kg/ha, with a row distance of 30 cm and 10 cm between plants within the row. The seedbed should be moist, firm and free of weeds. For optimal germination seed should be soaked in water for 24 hours and planted no deeper than 4 cm. In India the crop is sometimes grown from transplanted seedlings. Sowing early in the rainy season is less important for proso millet than for cereals such as sorghum and pearl millet, as yield reduction due to late sowing is relatively small. Proso millet is usually grown as a sole crop, but may be intercropped with other cereals and with pulses.
In-vitro regeneration of proso millet is possible on Murashige and Skoog medium, using excised embryos, shoot tips and segments of young inflorescences.
Management
The first weeks after sowing are critical in proso millet cultivation, as initial growth is slow, thus making competition with weeds difficult. In Kenya the first weeding of proso millet is recommended to take place at 2–3 weeks after emergence of the seedlings, and the second 2 weeks later. Little is known about the fertilizer response of proso millet. In India recommended fertilizer rates are 20–40 kg N, 20 kg P and 0–20 kg K per ha. Proso millet is usually grown as a rainfed crop, but in India it is sometimes irrigated. In Russia proso millet is usually grown in rotation with a forage grass, wheat or barley. In Bangladesh the rotation may comprise a pulse, wheat, jute, rice, potato or a Brassica crop.
Diseases and pests
Proso millet is relatively little affected by diseases and pests. The most important disease is smut (Sphacelotheca destruens and Ustilago spp.). Control measures include seed treatment with fungicide (copper sulphate) and crop rotation. Other diseases recorded are anthracnose (Colletotrichum graminicola), leaf blast (Pyricularia grisea), downy mildew (Sclerospora graminicola), ergot (Claviceps spp.), rust (Puccinia and Uromyces spp.), leaf blight (Helminthosporium sp.) and foot rot (Sclerotium rolfsii). The bacterium Xanthomonas holcicola can cause melanopathy, a darkening of the endosperm.
Proso millet can be damaged severely by maggots of the shootfly (Atherigona miliaceae), which attack the growing point. Infestation usually begins in the seedling stage, but may also occur in older plants. Tolerant lines have been identified in India. Other pests that are sometimes troublesome include stem borers (Chilo partellus, Chilo suppressalis and Sesamia inferens), midges, bugs, army worms, grasshoppers and termites. Birds and rats may destroy a considerable part of the harvest.
Harvesting
Proso millet is ready for harvest when the seed has a moisture content of 14–15%. Delayed harvesting should be avoided, as the seed shatters easily if allowed to become too mature. Premature harvesting, on the other hand, results in reduced yield and quality. Plants are usually harvested by pulling them up by the roots, and they are threshed immediately to avoid grain loss. If proso millet is harvested during the rainy season with high relative humidity, the grain must be dried to 14% moisture content. Households usually dry the grains over fire.
Yield
The average yield of proso millet under rainfed conditions is 400–700 kg/ha. With sufficient rain and fertile soils or under irrigation and with application of fertilizers, yields of over 2 t/ha have been obtained. The milling recovery is 70–80%.
Handling after harvest
Proso millet grain stores well for up to 5 years. Because of its small size it is hardly susceptible to insect attack. In India it is stored in granaries with clay walls or clay jars; sometimes the grain is mixed with ash or slightly baked before storage. It should be stored at 13% moisture content or less.
Genetic resources
The largest germplasm collections of Panicum miliaceum are held in Russia (N.I. Vavilov AllRussian Scientific Research Institute of Plant Industry, St. Petersburg, about 9000 accessions), China (Institute of Crop Germplasm Resources (CAAS), Beijing, about 7500 accessions) and Ukraine (Institute of Plant Production, Kharkiv, about 5000 accessions; Ustimovskaya Experimental Station for Plant Cultivation, Ustimovka, about 3500 accessions). In tropical Africa, accessions are held in Kenya (National Genebank of Kenya, Crop Plant Genetic Resources Centre, KARI, Kikuyu). In China, proso millet germplasm is being evaluated for resistance to smut, salt tolerance and nutritional quality. Of 4200 accessions described in China, 53% were non-glutinous.
Breeding
In Kenya some selection work with local lines and lines obtained from ICRISAT has been carried out. The recommended cultivar in Kenya is ‘KAT/PRO-1’, developed by Kenya Agricultural Research Institute (KARI). It was selected from ‘N40101’, an introduction from the former Soviet Union, received through ICRISAT. ‘KAT/PRO-1’ was derived from single plants selected for erect tillers, large inflorescences and large grains, and repeated cycles of mass selection of the progeny for the same traits and high yield potential. This cultivar is self-pollinated, has an open inflorescence and cream-coloured grains. It has the ability to stop growing when under severe drought stress, but it recovers quickly and resumes growth when the source of the stress is removed. It can be grown up to 2000 m altitude, becomes about 80 cm tall, flowers in 40–50 days, and matures in 65–80 days, depending on altitude and season. The average yield of ‘KAT/PRO-1’ was 1400 kg/ha, which was 50% higher than the mean of the local cultivars.
Breeding programmes in India and Russia aim at a higher productivity (drought resistance and earlier or late maturity), disease resistance (especially to smut) and grain quality (uniform size and shape, yellow endosperm with high carotenoid content). The main breeding method employed in Russia is intraspecific hybridization. The floral morphology of proso millet (small florets with tightly held lemma and palea) makes emasculation prior to anthesis and artificial crossing difficult, but techniques were developed in the United States and a number of cultivars have been released since 1984. In the United States breeding efforts include the development of cultivars with higher yield, better harvestability and large grain. In addition, germplasm with waxy starch characteristics (used for steam breads in South-East Asia) is being developed, to expand the export potential for proso millet in the United States.
Interspecific crossing of Panicum miliaceum with some other Panicum species resulted in abnormal embryos, which could be rescued by in-vitro ovary culture. Pollen sterility of the hybrid progeny could partly be overcome by in-vitro propagation.
Prospects
The production of proso millet is declining and the crop is being replaced in the human diet by other cereals, especially rice, wheat and maize. However, it will continue to be an important staple in semi-arid areas where hardly any other cereal can be grown. Proso millet is considered a potentially useful quick-maturing crop for the drier regions of tropical Africa, to fill the hunger gap before the main cereals are harvested. Major constraints are low returns due to high labour requirements (mainly for bird scaring, but also for planting and weeding) and low yields, limited alternative uses, existing eating habits, and a lack of information on the crop. Measures resulting in less tillering, e.g. narrow distances between rows, give a more uniform crop maturity and will reduce labour requirements for bird scaring. The export market for millets in general will remain small, as millet prices tend to be too high compared with those of other cereals. Further development of niche markets, e.g. waxy starch for Asian markets, may improve the export potential of proso millet.
Major references
- Cardenas, A., Nelson, L. & Neild, R., 1984. Phenological stages of proso millet. University of Nebraska, Lincoln, United States. 8 pp.
- FAO, 1995. Sorghum and millets in human nutrition. FAO food and nutrition series No 27. Food and Agriculture Organization, Rome, Italy. 184 pp.
- Fröman, B. & Persson, S., 1974. An illustrated guide to the grasses of Ethiopia. CADU (Chilalo Agricultural Development Unit), Asella, Ethiopia. 504 pp.
- Hulse, J.H., Laing, E.M. & Pearson, O.E., 1980. Sorghum and the millets: their composition and nutritive value. Academic Press, London, United Kingdom. 997 pp.
- Ministry of Agriculture and Rural Development, 2002. Field crops technical handbook. 2nd Edition. Ministry of Agriculture and Rural Development, Nairobi, Kenya. 219 pp.
- M’Ragwa, L.R.F. & Watson Jr, C.E., 1994. Registration of ‘KAT/PROB1’ proso millet. Crop Science 34: 1689–1690.
- Penninkhoff, P., 1984. The prospects of growing proso millet in arid and semi-arid areas of Kenya. East African Agricultural and Forestry Journal 44: 298–305.
- Riley, K.W., Gupta, S.C., Seetharam, A. & Mushonga, J.N. (Editors), 1993. Advances in small millets. Oxford & IBH Publishing, New Delhi, India. 557 pp.
- Seetharam, A., Riley, K.W. & Harinarayana, G., 1990. Small millets in global agriculture. Proceedings of the first international small millets workshop, Bangalore, India, October 29 – November 2, 1986. Aspect Publishing, London, United Kingdom. 392 pp.
- van der Hoek, H.N. & Jansen, P.C.M., 1996. Panicum miliaceum L. cv. group Proso Millet. In: Grubben, G.J.H. & Partohardjono, S. (Editors). Plant Resources of South-East Asia No 10. Cereals. Backhuys Publishers, Leiden, Netherlands. pp. 115–119.
Other references
- Bajaj, Y.P.S., Sidhu, B.S. & Dubey, V.K., 1981. Regeneration of genetically diverse plants from tissue cultures of forage grass - Panicum spp. Euphytica 30: 135–140.
- Baltensperger, D.D., 1996. Foxtail and proso millet. In: Janick, J. (Editor). Progress in new crops. ASHS Press, Alexandria, Virginia, United States. pp. 182–190.
- Baltensperger, D.D., 2002. Progress with proso, pearl and other millets. In: Janick, J. & Whipkey, A. (Editors). Trends in new crops and new uses. ASHS Press, Alexandria, Virginia, United States. pp. 100–103.
- Bohle, B., Hirt, W., Nachbargauer, P., Ebner, H. & Ebner, C., 2003. Allergy to millet: another risk for atopic bee keepers. Allergy 58: 324–328.
- CSIR, 1966. The wealth of India. A dictionary of Indian raw materials & industrial products. Raw materials. Volume 7: N–Pe. Publications and Information Directorate, Council of Scientific and Industrial Research, New Delhi, India. 330 pp.
- de Wet, J.M.J., 1995. Minor cereals. In: Smartt, J. & Simmonds, N.W. (Editors). Evolution of crop plants. 2nd Edition. Longman, London, United Kingdom. pp. 202–208.
- Douglas, N.J., 1974. Millets for grain and grazing. Queensland Agricultural Journal 100(10): 469–476.
- Gibberd, V., 1996. Significance of planting date and choice of crop variety for food crop security in Kenya’s semi-arid areas. Tropical Science 36: 101–108.
- Hanelt, P. & Institute of Plant Genetics and Crop Plant Research (Editors), 2001. Mansfeld’s encyclopedia of agricultural and horticultural crops (except ornamentals). 1st English edition. Springer Verlag, Berlin, Germany. 3645 pp.
- Haq, N., 1989. Crop plants: potential for food and industry. In: Wickens, G.E., Haq, N. & Day, P. (Editors). New crops for food and industry. Chapman and Hall, London, United Kingdom. pp. 246–256.
- ICRISAT & FAO, 1996. The world sorghum and millet economies: facts, trends and outlook. ICRISAT, Patancheru, India & FAO, Rome, Italy. 68 pp.
- Kashin, A.S., Kostyutchkova, M.K., Blyudneva, E.A. & Davoyan, N.I., 1997. Interspecific crosses of Panicum miliaceum L. with a distant millet species. International Sorghum and Millet Newsletter 38: 150–151.
- M’Ragwa, L.R. & Kanyenji, B.M., 1987. Strategies for the improvement of sorghum and millet in semi-arid Kenya. In: Menyonga, J.M., Bezuneh, T. & Youdeowei, A., 1987. Food grain production in semi-arid Africa. Proceedings of an international drought symposium held at the Kenyatta Conference Centre, Nairobi, Kenya, 19th to 23rd May, 1986. OAU/STRC-SAFGRAD, Ouagadougou, Burkina Faso. pp. 173–189.
- Nelson, L.A., 1984. Technique for crossing proso millet. Crop Science 24: 205–206.
- Nishizawa, N., Sato, D., Ito, Y., Nagasawa, T., Hatakeyama, Y., Choi, M.-R., Choi, Y.-Y. & Wei, Y.-M., 2002. Effects of dietary protein of proso millet on liver injury induced by D-galactosamine in rats. Bioscience, Biotechnology and Biochemistry 66(1): 92–96.
- Petr, J., Michalik, I., Tlaskalova, H., Capouchova, I., Famera, O., Urminska, D., Tukova, L. & Knoblochova, H., 2003. Extension of the spectra of plant products for the diet in coeliac disease. Czech Journal of Food Sciences 21(2): 59–70.
- Purseglove, J.W., 1972. Tropical crops. Monocotyledons. Volume 1. Longman, London, United Kingdom. 334 pp.
- Seetharam, A., 1998. Small millets research: achievements during 1947–97. Indian Journal of Agricultural Sciences 68(8): 431–438.
- USDA, 2004. USDA national nutrient database for standard reference, release 17. [Internet] U.S. Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory, Beltsville Md, United States. http://www.nal.usda.gov/fnic/foodcomp. October 2004.
- Veldkamp, J.F., 1996. Revision of Panicum and Whiteochloa in Malesia (Gramineae B Paniceae). Blumea 41: 181–216.
Sources of illustration
- van der Hoek, H.N. & Jansen, P.C.M., 1996. Panicum miliaceum L. cv. group Proso Millet. In: Grubben, G.J.H. & Partohardjono, S. (Editors). Plant Resources of South-East Asia No 10. Cereals. Backhuys Publishers, Leiden, Netherlands. pp. 115–119.
Author(s)
- R.N. Kaume, P.O. Box 583, 90200 Kitui, Kenya
Correct citation of this article
Kaume, R.N., 2006. Panicum miliaceum L. In: Brink, M. & Belay, G. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 17 December 2024.
- See the Prota4U database.
