|Ripe proso millet|
Proso millet (Panicum miliaceum) is also known as common millet, hog millet or white millet. Both the wild ancestor and the location of domestication of proso millet are unknown, but it first appears as a crop in both Transcaucasia and China about 7,000 years ago, suggesting it may have been domesticated independently in each area. It is still extensively cultivated in India, Russia, Ukraine, the Middle East, Turkey and Romania. In the United States, proso is mainly grown for birdseed. It is sold as health food, and due to its lack of gluten, it can be included in the diets of people who cannot tolerate wheat.
Proso is well adapted to many soil and climatic conditions; it has a short growing season, and needs little water. The water requirement of proso is probably the lowest of any major cereal. It is an excellent crop for dryland and no-till farming. Proso millet is an annual grass whose plants reach an average height of 100 cm (4 feet.). Like corn, it has a C4 photosynthesis. The seedheads grow in bunches. The seeds are small (2–3 mm or 0.1 inch) and can be cream, yellow, orange-red, or brown in colour.
History and domestication
Unlike the foxtail millet, the wild ancestor of the proso millet has not yet been satisfactorily identified. Weedy forms of this grain are found in central Asia, covering a widespread area from the Caspian Sea east to Xinjiang and Mongolia, and it may be that these semiarid areas may harbor "genuinely wild P. miliaceum forms." This millet has been reportedly found in Neolithic sites in Georgia (dated to the fifth and fourth millennia BC), as well as excavated Yangshao culture farming villages east in China. Proso millet appears to have reached Europe not long after its appearance in Georgia, first appearing in east and central Europe; however, the grain needed a few thousand more years to cross into Italy, Greece, and Iran, and the earliest evidence for its cultivation in the Near East is a find in the ruins of Nimrud, Iraq dated to about 700 BC.
While proso millet is not a member of the Neolithic Near East crop assemblage, it arrived in Europe no later than the time these introductions did, and proso millet as an independent domestication could predate the arrival of the Near East grain crops.
Proso millet is a relatively low demanding crop and diseases aren’t known. That’s why Proso millet is often used in organic farming systems in Europe. In the United States it is often used as an intercrop. Thereby, proso millet can help to avoid a summer fallow, and continuous crop rotation can be achieved. Its superficial root system and its resistance to atrazine residue make proso millet a good intercrop between two water and pesticide demanding crops. The stubbles of the last crop, by allowing more heat into the soil, result in a faster and earlier millet growth. While millet occupies the ground, because of its superficial root system, the soil can replenish in water for the next crop. The later, for example a winter wheat, can in turn benefits from the millet stubbles, which can notably act as snow accumulators.
Climate and soil requirements
Due to its C4 photosynthetic system, Proso millet is thermopile like maize. Therefore shady locations of the field should be avoided. Further it is sensitive to cold temperatures lower than 10 to 13 degrees Celsius. Proso millet is highly drought resistant what makes it interesting to regions with low water availability and longer Periods without rain. The soil should be lightly or medium-heavy. Due to its flat root systems, soil compaction must be prohibited. Furthermore Proso millet doesn’t tolerate wetness due to dammed-up water.
Seedbed & Sowing
The seedbed should be fine crumbled like for sugar beet and rapeseed. In Europe proso millet is sowed between mid April and the end of Mai. 500g/are of seeds are required which comes up to 500 grains/m2. In organic farming this amount should be increased if a harrow weeder is used. For sowing the normal sowing machines could be used similar they are used for other crops like wheat. A distance between the rows among 16 to 25 centimeters is recommended if the farmer uses an inter row cultivator. The sowing depth should be 1.5 up to 2 cm in optimal soil or 3 to 4 cm in dry soil. Rolling of the ground after sowing is helpful for further cultivation. Cultivation in no till farming systems is also possible and often done in the US. The sowing then could be done two weeks later.
Only a few diseases and pests are known but they aren’t very important. Bigger problems are weeds. The critical phase is the juvenile development. The formation of the grains happens in the 3 up to 5 leaf stadium. After that all nutrients should be available for the proso millet. Therefore it is necessary to oppress the development of weeds. In conventional farming herbicides could be used. In organic farming it’s possible to use harrow weeders and inter row cultivators. For that special sowing parameters described in the chapter above are needed. For a good development of the plant fertilization with 50 to 75 kg nitrogen per hectare is recommended. Planting proso millet in a crop rotation after maize should be avoided due to its same weed spectrum. Because proso millet is an undemanding crop, it also could be at the end of the crop rotation.
Harvesting & postharvest treatments
Harvest time is at the end of August until mid September. To determine the best harvest time isn’t that easy because the ripeness of the grains isn’t synchronized. The grains on the top of the panicle are ripe first while the grains in the lower parts need more time. That’s why it’s necessary to find a compromise and catch the date when the yield is highest. Harvesting could be done with a conventional combine harvester at moisture of the grains about 15-20%. Usually proso millet is mowed at windrows first because the plants aren’t dry like wheat. There they could wither which makes the threshing easier. Then the harvest is done with a pickup attached to the combine. The possible yield is between 2.5 and 4.5 tons per hectare under optimal conditions. Studies in Germany showed that even a higher yield could be reached.
Proso millet is one of the few types of millet not cultivated in Africa. In the United States, former Soviet Union, and some South American countries, it is primarily grown for livestock feed. As a grain fodder, it is very deficient in lysine and needs complementation. Proso millet is also a poor fodder due to its low leaf:stem ratio and a possible irritant effect due to its hairy stem. Foxtail millet, having a higher leaf:stem ratio and less hairy stems, is preferred as fodder, particularly the variety called moha, which is a high quality fodder.
In order to promote millet cultivation, other potential uses have been considered recently. For example, starch derived from millets has been shown to be a good substrate for fermentation and malting with grains having similar starch contents as wheat grains. A recently published study suggested that starch derived from Proso millet can be converted to ethanol with an only moderately lower efficiency than starch derived from corn. The development of varieties with highly fermentable characteristics could improve ethanol yield to that of highly fermentable corn. Since Proso Millet is compatible with low input agriculture, cultivation on marginal soils for biofuel production could represent an important new market, for example for farmers in the High Plains of the US. The demand for more diverse and healthier cereal-based foods is increasing, particularly in affluent countries. This could create new markets for proso millet products in human nutrition. Protein content in proso millet grains is comparable with that of wheat, but the share of essential amino acids (leucine, isoleucine and methionine) is substantially higher in proso millet. In addition, health-promoting phenolic compounds contained in the grains are readily bioaccessible and high Calcium contents favor bone strengthening and dental health. Among the most commonly consumed products are ready-to-eat breakfast cereals made purely from millet flour  as well as a variety of noodles and bakery products, which are, however, often produced from mixtures with wheat flour to improve their sensory quality.
- Daniel Zohary and Maria Hopf, Domestication of plants in the Old World, third edition (Oxford: University Press, 2000), p. 83
- Zohary and Hopf, Domestication, p. 86
- Producing and marketing proso millet in the great plains, U. Nabraska-Lincoln Extension
- Merkblatt für den Anbau von Rispenhirse im biologischen Landbau, www.biofarm.ch, http://www.biofarm.ch/assets/files/Landwirtschaft/Merkblatt_Biohirse_Version%2012_2010.pdf (23.11.14)
- Pearl Millet and Other Millets, Wayne W. Hanna, David D. Baltensperger, Annadana Seetharam (2004)
- National Research Council (1996-02-14). "Ebony". Lost Crops of Africa: Volume I: Grains. Lost Crops of Africa 1. National Academies Press. p. 260. ISBN 978-0-309-04990-0. Retrieved 2008-07-18.
- Rose, D.J., Santra, D.K., 2013. Proso millet (Panicum miliaceum L.) fermentation for fuel ethanol production. Industrial Crops and Products 43, p. 602-605.
- Taylor, J.R.N., Schober, T.J., Bean, S.R., 2006. Novel food an non-food uses for sorghum and millets. Journal of Ceral Science 44, p. 252-271.
- Saleh, A.S.M., Zhang, Q., Chen, J., Shen, Q., 2012. Millet Grains: Nutritional Quality, Processing, and Potential Health Benefits. Comprehensive Reviews in Food Science and Food Safety 12, p. 281-295.