«Eragrostis tef(Zucc.) Trotter Seyfu Ketema Biodiversity Institute Addis Abeba, Ethiopia 2 Tef. Eragrostis tef (Zucc.) Trotter The International Plant ...»
Tef. Eragrostis tef (Zucc.) Trotter 10 Melak Hail and Guard (1966) studied the development of the embryo sac and embryo of tef. They reported that the development of the female gametophyte was normal and of the monosporic type common to most angiosperms. The three antipodals divide several times as is common in grasses. Study of many ovules before and after fertilization showed absence of any apomictic type of embryo formation. Fertilization was found to occur in the basal floret of a spikelet when that floret was at the base of the flag leaf blade. The maturation of flowers is basipetal on the panicle and on each branch, while acropetal on the spikelet basis.
The flowers of tef are hermaphroditic with both the stamens and pistils being found in the same floret. Florets in each spikelet consist of three anthers, two stigmas and two lodicules that assist in flower opening. Tef is a self pollinated chasmogamous plant.
The degree of outcrossing in tef is very low, 0.2-l.0% (Kemal Ali, 1996, pers. comm.).
Promoting the conservation and use of underutilized and neglected crops. 12. 11 3 Origin and centre of diversity Centre of diversity Tef is endemic to Ethiopia and its major diversity is found only in that country As with several other crops, the exact date and location for the domestication of tef is unknown. However, there is no doubt that it is a very ancient crop in Ethiopia, where domestication took place before the birth of Christ.
According to Ponti (1978) tef was introduced to Ethiopia well before the Semitic invasion of 1000 to 4000 BC. It was probably cultivated in Ethiopia even before the ancient introduction of emmer and barley According to Tadesse (1975) tef seeds found by Unger (1866) in the Pyramid of Dashur (3359 BC) and from the ancient Jewish town of Ramses in Egypt (ca. 1300 BC) were probably E. aegyptiaca or E. pilosa and thus are not good evidence for the cultivation of tef in ancient Egypt.
According to Costanza (1974), Haudricourt (1941) suggested that the word tef might have been derived from the Semitic thaf applied in Yemen to a wild harvested cereal. However, according to the same source, Porteres (1958) “listed definitions of ‘thaf’ given in an Arabic dictionary: 'Thaf' is a plant growing in Yemen, whose grains resemble those of red mustard which are eaten during famine. A bread made of
Dourra flour.” Among other things Porteres concluded the following:
The word tef does not seem to have been introduced into the Abyssinian plateau by the Semitic people who already used the supposed derivative thaf. Instead, tef might be from an Egypto-Cushitic base. Like the cereal, the name scarcely spread beyond northeastern Africa, the only centre known for the crop.
The Abyssinian Semites probably borrowed the name from the populations they found on the plateau who were already cultivating tef, when they invaded them.
If the Semites had started tef cultivation, one would expect to find evidence of its cultivation in central Asia and by the European Aryan people. It would be found across to the Indian Ocean in the mountain regions.
No word in Indian languages, or in the languages of Arabia or in the Mesopotamian area, resembles tef in sound or in connoting nourishment.
On the basis of linguistic, historic, geographic and botanical notes, tef is assumed to have originated in northeastern Africa. The current area of cultivation is probably not the initial one of domestication; domestication probably occurred in the western area of Ethiopia, where agriculture is precarious and seminomadal.
Distribution of the genus and some species related to tef Within the genus Eragrostis 43% of the species seem to have originated in Africa, 18% in South America, 12% in Asia, 10% in Australia, 9% in Central America, 6% in North America and 2% in Europe (Costanza 1974). Of the 54 Eragrostis species listed in Ethiopia, 14 (or 26%) are endemic (Cufodontis 1974).
The fact that several endemic and nonendemic species of Eragrostis, some of which are considered the wild relatives of tef, are found in Ethiopia and, in addition, 12 Tef. Eragrostis tef (Zucc.) Trotter the fact that the genetic diversity for tef exists nowhere in the world except in Ethiopia, indicates that tef originated and was domesticated in Ethiopia. Vavilov (1951) has identified Ethiopia as the centre of origin and diversity of tef.
In a study to trace the origin and domestication of tef and identify the species related to it, Ponti (1978) stated that a noticeable difference between tef and related species is the complete absence of glands in the cultivated species. Progenitors of tef, she states, are therefore likely to have been eglandular plants and the presentday distribution of eglandular representatives of closely related species may provide evidence for the original area of tef domestication. With this hypothesis Ponti made a survey of the collections of E. pilosa, E. aethiopica, E. cilianensis, E. minor a n d E. barrelieri at the herbarium of the Royal Botanic Gardens, Kew, to ascertain the distributions of eglandular plants of these taxa in Africa, Asia and Europe and prepared maps to show the geographical distribution of glands in these species (Fig. 3). She concluded that “combining the geographical data obtained for all the species examined, there may be a concentration, of eglandular forms in Africa, notably in the North-east (Sudan, Egypt, Ethiopia, Uganda and Kenya). Except in E. pilosa, where eglandular forms are widespread, eglandular representatives of otherwise glandular species are rare outside Africa. It seems probable, therefore, that tef was domesticated in Northeast Africa from such plants.”
Wild relatives of tef Tef is considered an allotetraploid crop (Tareke 1981; Tavassoli 1986). However, there is no definite information to date regarding the diploid putative parents that contributed to the origin of tef. Nevertheless, based on morphological data the following species have been identified, by different researchers, as the ancestors and
contributors to the origin of tef or as species closely related to tef:
Species suggested as ancestors of tef (Costanza 1974) are Eragrostis pilosa, E. macilenta, E. aethiopica, E. pseudo tef, E. longifolia and E. atrovirens.
Species suggested as contributors to the origin of tef (Endeshaw 1978) are E. pilosa, E. curvula, E. aethiopica, E. cilianensis, E. mexicana and E. bicolor.
Species suggested as very closely related to tef (Ponti 1978) are E. pilosa a n d E. aethiopica; E. mexicana, E. cilianensis, E. minor and E. barrelieri sufficiently related;
while E. macilenta and E. aegyptica are suspected to be close enough but need further investigation. Among perennials, E. papposa, E. heteromera and E. bicolor are more closely related to tef than others.
Species suggested as closely related to tef based on cytological evidence (Tavassoli 1986) are E. aethiopica 2x, E. pilosa 2x, E. mexicana 6x, E. barrelieri 6x, E. minor 2x, 4x and E. cilianensis 2x, 4x, 6x.
Geographic distribution Most of the Ethiopian farmers use traditional landraces of tef and these are distributed all over the country. Local cultivars such as Gea-Lamie, Dabi, Shewa-Gimira, Beten and Bunign, which are early maturing varieties (85 days), are widely used in areas that have a short growing period due to low moisture stress or low temperature. The same varieties are also used in areas with adequate rainfall and where double cropping is practised. In the highly productive and major tef-producing regions of Gojam and Shewa, and in other regions where environmental stress is not severe, the local cultivars such as Alba, Ada and Enatit are used. Modem varieties are used in many regions but in very small areas within each region. In the regions of Gojam and Shewa, which are located in the central highlands of Ethiopia and are also the largest and major tefproduction areas in the country modern varieties are used as well as traditional landraces
and local cultivars. The most widely used modern varieties in these regions are:
DZ-01-354, has very wide adaptation, a cream-white seed colour and high grain yield;
DZ-01-196 is not as widely adapted and high yielding as DZ-01-354 but is very popular with farmers because of its very white seed colour which fetches the highest market price for its grain-quality in the country;
DZ-01-787 has specific adaptation, cream-white seed colour, better tolerance to rust and high grain yield;
DZ-Cross-37 has wide adaptation, cream-white seed colour, medium maturity (90 days) and is suitable to areas having a short growing period. In the region of Welo, Tigray, many areas of the rift valley and other areas that suffer from low moisture stress, DZ-Cross-37 is used.
Tef. Eragrostis tef (Zucc.) Trotter 14 Tef has been introduced to different parts of the world through various institutions and individuals. The Royal Botanic Gardens, Kew, imported seed from Ethiopia in 1866 and distributed it to India, Australia, the USA and South Africa.
According to Tadesse (1975), Burt Davy in 1916 introduced tef to California (USA), Malawi, Zaire, India, Sri Lanka, Australia, New Zealand and Argentina; Skyes in 1911 introduced it to Zimbabwe, Mozambique, Kenya, Uganda, Tanzania; Horuitz in 1940 to Palestine.
Promoting the conservation and use of underutilized and neglected crops. 12. 15 4 Properties The composition of tef is similar to that of millet, although it contains generally higher amounts of the essential amino acids, including lysine, the most limiting amino acid (Jansen et al. 1962). The amino acid composition of tef is excellent, its lysine content is higher than that of all cereals except rice and oats, it has good mineral content and its straw is nutritious (Tables 1, 2 and 3). The fractional composition of the protein in tef indicated that glutelins and albumins were the major protein storage components and their order of fractional importance was: glutelins 44.55% albumins 36.6% prolamin 11.8% globulins 6.7% (Mulugeta 1978). In tef seed the distribution of protein, percentage of ash and mineral elements is higher in the pericarp than in the endosperm (Mulugeta 1978).
According to Melak Hail (1966), compared with other cereals tef is reported to have a higher iron content. But Abraham et al. (1980) disagreed with Melak Hail’s (1966) conclusions and reported that the iron content of tef is not more than that of other common cereals. However, they confirmed that tef has a relatively high iron content owing to its contaminants, which peak during threshing on the ground.
According to Tadesse (1969), Molineaux and Biru (1965) reported that non-tef consumers have a lower level of haemoglobin, and hookworm anaemia develops in non-tef eaters if they are infested with hookworm. On the other hand, since tef eaters have higher levels of haemoglobin in their blood, they do not suffer from hookworm Table 1. Amino acid content of tef (g/16 g N) compared with other cereals, the FAO pattern and whole egg
Table 2. Chemical composition of tef seed compared with that of spring wheat, winter wheat, winter barley, and sorghum (Melak Hail 1966)
† DM = dry matter; CP = crude protein; NDF = neutral detergent fibre.
anaemia even when infested. In addition, according to the same study, malaria is frequently ‘found in the groups with lower haemoglobin levels. Moreover, consuming tef is reported to prevent the anaemia related to pregnancy (Tareke Berhe, 1996, pers. comm.). Tef contains more calcium, copper, zinc, aluminium and barium than winter wheat, barley and sorghum (Melak Hail 1966).
17 Promoting the conservation and use of underutilized and neglected crops. 12.
5 Uses In Ethiopia tef is traditionally grown as a cereal crop. The grain is ground to a flour which is mainly used for making a popular pancake-like local bread called enjera and sometimes for making porridge. The grain is also used to make local alcoholic drinks, called tela and katikala. Tef straw, besides being the most appreciated feed for cattle, is also used to reinforce mud and plaster the walls of tukuls and local grain storage facilities called gotera. Tef grain, owing to its high mineral content, has started to be used in mixtures with soyabean, chickpea and other grains in the baby food industry.
Enjera made from tef is traditionally consumed with wot, a sauce made of meat or ground pulses like lentil, faba bean, field pea, broad bean and chickpea. This indicates that the traditional way of consuming tef with wot, is wise, since the wot, supplements the lysine deficit in tef and provides a better balanced diet.
Tadesse (1969) and Beyene (1965) suggested that fenugreek (Trigonella foenumgraecum) is a good supplement if used with tef. In some regions of Ethiopia, e.g.
Welo, women usually prepare enjera by adding some fenugreek to tef to improve its baking quality. Because of this, the enjera becomes softer and has a shiny appearance.
Thus women should be encouraged to continue this traditional practice and be made aware that their practice not only has the benefit of improving the baking quality of the enjera but also of supplementing its protein content, especially lysine.
The most popular and widely preferred form of enjera is prepared from unmixed pure tef flour. The next preferred enjera is the one prepared by mixing tef flour with the flower of other cereals such as barley, wheat, maize or sorghum.
Tef is predominantly grown in Ethiopia as a cereal crop and not as a forage crop.
However, when grown as a cereal, farmers highly value the straw of tef and it is stored and used as a very important source of animal feed, especially during the dry season. Farmers feed tef straw preferentially to lactating cows and working oxen.
Cattle prefer tef straw to the straw of any other cereal and its price is higher than that of other cereals. According to Lulseged and Jamal (1989), the quantity and quality of residues from various cereal crops vary greatly depending on the crop species. Wheat and barley usually give high straw yields, though of inferior quality.