Triticum turgidum (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

General importance
Geographic coverage Africa
Geographic coverage World
Cereal / pulse
Forage / feed
Fibre
Food security

distribution in Africa (planted)

1, inflorescences; 2, spikelet; 3, grains. Redrawn and adapted by Achmad Satiri Nurhaman

emmer wheat

spike

immature spike

Triticum turgidum L.

Protologue: Sp. pl. 1: 86 (1753).

Family: Poaceae (Gramineae)

Chromosome number: 2n = 28

Synonyms

• Triticum dicoccon Schrank (1789),
• Triticum durum Desf. (1798).

Vernacular names

• Durum wheat, macaroni wheat (En).
• Blé dur (Fr).
• Trigo duro, trigo rijo (Po).

Origin and geographic distribution

Hybridization between the diploids Triticum urartu Tumanian ex Gandylian (A-genome) and the yet unconfirmed B-genome donor (possibly a species of Aegilops section Sitopsis), followed by chromosome doubling gave rise to the first wild tetraploid wheat. Remains of primitive types of cultivated Triticum turgidum (emmer wheat, which has hulled grain) were discovered at several archaeological sites in Syria and dated at around 8000 BC. Emmer wheat became the predominant cultivated wheat in the Fertile Crescent (southern Turkey, northern Iraq and adjacent regions of Iran and Syria, as well the Joran valley) and spread into much of Asia, northern Africa and Europe. It remained the main wheat for several thousands of years. Free-threshing types, such as durum wheat, arose by accumulation of mutations and subsequent selection from the primitive emmer wheat. Around the beginning of the Christian era durum wheat had replaced emmer in most of the wheat growing areas of the Old World. Durum wheat is now commercially the most important type of Triticum turgidum. It is not certain when and how durum wheat reached tropical Africa, but it might have reached the northern highlands of Ethiopia around 3000 BC. In tropical Africa durum wheat is predominantly grown in Ethiopia and to some extent in Eritrea and Angola. In other countries, e.g. Sudan and Tanzania, it has been grown experimentally. Durum wheat is also widely grown in northern Africa (from Morocco to Egypt), Mediterranean Europe (Italy, southern France), Turkey, the Middle East (Syria, Jordan, Iraq), Russia, Asia (Iran, Afghanistan, India, China), North America (Canada and the United States) and Argentina.

Uses

Throughout the world durum wheat is mainly ground to semolina (coarse flour) that is made into various pasta products (macaroni, spaghetti, noodles) and traditional flat bread (little leavened). In tropical Africa durum wheat utilization has been adapted to the local cuisine. In Ethiopia it is used mainly to make ‘kitta’ (unleavened bread), ‘injera’ (flat pancake-like unleavened bread), and homemade alcoholic and non-alcoholic drinks. Durum wheat is also preferred for preparation of ‘kinchie’ (crushed kernels, cooked with milk or water and mixed with spiced butter), which is often served for breakfast. The grain is eaten as a snack and during social gatherings as ‘nifro’ (boiled whole grain often mixed with pulses), ‘kollo’ (roasted grain), and ‘dabo-kollo’ (ground and seasoned dough, shaped and deep fried). In northern Africa and the Middle East durum wheat is preferred for making couscous; its granules result from the agglomeration of semolina particles. In the Middle East it is also durum wheat which is used for making ‘bulghur’, i.e. a wheat which is parboiled, dried and then crushed.

The straw of durum wheat is fed to animals and used as bedding material for animals and for thatching.

Production and international trade

Durum wheat and bread wheat statistics are usually combined and therefore individual and reliable statistics on durum wheat are difficult to obtain. According to FAO estimates, the average world production of wheat grain (durum wheat and bread wheat together) in 1999–2003 amounted to 576 million t/year from 209 million ha. Worldwide, durum wheat constitutes less than 10% of the area under the cultivated wheats. Major durum wheat producers are northern Africa, where it covers nearly 50% of the total wheat area, the United States, Canada and the Russian Federation. The main durum wheat-producing country in tropical Africa is Ethiopia. Close to 50% of its total wheat production (1.4 million t/year in 1999–2003) is durum wheat. In Ethiopia durum wheat production is mainly for subsistence. Ethiopia also produced emmer wheat, but this crop is disappearing.

Properties

Durum wheat grain contains per 100 g edible portion: water 10.9 g, energy 1418 kJ (339 kcal), protein 13.7 g, fat 2.5 g, carbohydrate 71.1 g, Ca 34 mg, Mg 144 mg, P 508 mg, Fe 3.5 mg, Zn 4.2 mg, vitamin A 0 IU, thiamin 0.42 mg, riboflavin 0.12 mg, niacin 6.7 mg, vitamin B₆ 0.42 mg, folate 43 μg and ascorbic acid 0 mg. The essential amino-acid composition per 100 g edible portion is: tryptophan 176 mg, lysine 303 mg, methionine 221 mg, phenylalanine 681 mg, threonine 366 mg, valine 594 mg, leucine 934 mg and isoleucine 533 mg. The principal fatty acids are per 100 g edible portion: linoleic acid 930 mg, palmitic acid 422 mg and oleic acid 335 mg (USDA, 2005). Durum wheat grain is deficient in the amino acids lysine and threonine, and somewhat in isoleucine and valine. It is a good source of B-group vitamins and minerals. Durum wheat grain is vitreous, amber in colour, and is the hardest of all wheats. The physical and chemical characteristics of durum wheat gluten provide greater stability of the dough and make it specially suited for pasta products. For preparation of pasta, the grain is milled only as far as the semolina stage; a finely ground flour is not required. In the process of cooking, pasta products of good quality do not disintegrate or become soft, mushy, starchy or sticky. Protein should have a minimum level of 12%. Durum wheat is not suitable for making cakes and leavened bread because of its high gluten content and dough strength.

Description

• Annual, often strongly tufted grass up to 170 cm tall; stem (culm) cylindrical, smooth, hollow except at nodes.
• Leaves distichously alternate, simple and entire; leaf sheath rounded, auricled; ligule membranous; blade linear, 15–40 cm × 1–2 cm, parallel-veined, flat, slightly hairy.
• Inflorescence a terminal, dense, distichous spike 4–12 cm long, with sessile spikelets borne solitary on zigzag, hairy, tough rachis.
• Spikelet 10–15 mm long, laterally compressed, 4–7-flowered, with bisexual florets, but the 1–3 uppermost ones usually rudimentary; glumes almost equal, oblong, shorter than to almost as long as spikelet, thinly leathery, 5–11-veined, strongly keeled throughout, apiculate to awned; lemma rounded on back but keeled towards the tip, leathery, with an awn 8–20 cm long; palea 2-keeled, hairy on the keels; lodicules 2, ciliate; stamens 3; ovary superior, tipped by a small fleshy hairy appendage and with 2 plumose stigmas.
• Fruit an ellipsoid caryopsis (grain), at one side with a central groove.

Other botanical information

Triticum is a classic example of allopolyploidy consisting of diploid (2n = 14), tetraploid (2n = 28) and hexaploid (2n = 42) species. Selection at the diploid and tetraploid levels has proceeded from wild species with hulled grain and brittle rachis to the free-threshing species with tough rachis; hexaploid wheats are not known in the wild, they appeared in cultivation. The classification of the genus Triticum and other related genera within the tribe Triticeae was strongly debated. Polyploidy and biphyletic genome differentiation (B vs. G genome) are isolating mechanisms offering adequate species borders. In this approach, Triticum comprises only 5–6 species, including the diploid Triticum monococcum L. (grown sporadically in southern Europe and western Asia), the tetraploid Triticum turgidum L., and the hexaploid Triticum aestivum L.

Some tetraploid cultivated wheats are sometimes specifically distinguished from Triticum turgidum. Triticum aethiopicum Jakubz. is a special type of free-threshing wheat, a traditional cereal crop in Ethiopia and the southern part of the Arabian Peninsula. Its spikes are loose to dense, its glumes are usually awned and its grain mostly purple. Triticum dicoccon Schrank (emmer wheat) is the oldest cultivated tetraploid wheat, domesticated in the area of Palestine, south-western Syria and north-western Jordan. It has disarticulating spikes with 2-grained spikelets and hulled grains, not easy to decorticate. At present it is still cultivated in Ethiopia, Iran, Turkey, Transcaucasia, former Yugoslavia, the Czech Republic, Slovakia and India. Triticum durum Desf. is the free-threshing durum wheat or macaroni wheat, that appeared in the Mediterranean, and is cultivated in regions with a hot dry climate; it has its greatest diversity in Ethiopia. It has slender spikes and comparatively long glumes. Triticum polonicum is the free-threshing Galicia wheat (erroneously named ‘Polish wheat’ by Linnaeus), occasionally cultivated in the same areas as the true durum wheat. It has much longer glumes (2.5–3 cm). In Ethiopia it is found only in mixture with other wheats. The free-threshing rivet wheat or cone wheat (Triticum turgidum L. sensu stricto) is cultivated in northern Africa, southern and central Europe and Asia. It has stout spikes nearly square in section and comparatively short glumes. It is also grown in Ethiopia, usually in mixtures.

Most durum wheat cultivars are spring or semi-winter types. Only a few winter types are known.

Growth and development

Germination of wheat occurs at temperatures of 4–37°C, the optimum being 12–25°C. The coleoptile emerges 4–6 days after germination. Flowering begins at the middle third of the spike, then rapidly progressing both upward and downward. Durum wheat is predominantly self-pollinated; in Ethiopia cross-pollination rates up to 4.3% have been recorded. Physiological maturity is reached when the moisture content of the fully formed grain has dropped to 25–35%. The complete crop cycle of durum wheat is 90–115 days in Ethiopia.

Ecology

Durum wheat is better suited to regions with a low average annual rainfall than bread wheat, e.g. in the Middle East, northern Africa and parts of Mediterranean Europe. In the tropics durum wheat is best grown at higher elevations or in the cooler months of the year. In Ethiopia durum wheat is mostly produced in the central, northern and north-western highlands at 1800–2800 m altitude during the main rainy season (‘meher’) between August and December. Highly rust-resistant cultivars are needed to grow durum wheat below 1900 m in Ethiopia. High temperatures and low humidity improve grain quality, and durum wheat is susceptible to low temperatures and severe frosts. The minimum amount of water required for an acceptable crop is 250 mm.

Soils best suited for durum wheat are well aerated, well drained and deep, with 0.5% or more organic matter. Optimum soil pH is 5.5–7.5. Durum wheat is sensitive to soil salinity. In Ethiopia durum wheat is preferentially grown on heavy black clay soils (Vertisols); farmers usually delay planting and use surface drainage systems (furrows) to avoid waterlogging. N and micronutrient deficiencies can be limiting on Vertisols. Durum wheat can also be grown on light soils (Andosols), but here short, stiff and disease resistant cultivars are required.

Propagation and planting

Durum wheat is propagated by seed. The 1000-seed weight is 30–40 g. Durum wheat can be sown by hand or machine; in Ethiopia it is usually broadcast. Dormancy can be a problem in introduced cultivars, but not in the local Ethiopian landraces. Seeding rate is commonly 100–150(–175) kg/ha, the higher rates being necessary on heavy clay soils where stand establishment is usually poor on flat seedbeds. It is advisable to use certified seed that has been treated with fungicides against soil- and seed-borne diseases, but this is not practised in tropical Africa. In Ethiopia an oxen-drawn implement (‘maresha’) is used to till the land before sowing, with 2–3 ploughings made before planting. In Ethiopia planting dates vary from mid-July to early September.

Management

Weed competition during tillering of the durum wheat crop, usually in the first 10–50 days after sowing, is most detrimental to grain yield. Uniform crop stand and early vigour discourage weed growth. Competition occurring later in the crop cycle can affect grain numbers and grain weight, but usually has smaller effects on grain yield. Weeds can be controlled by hand weeding, proper crop rotation, pre-seeding irrigation, machine cultivation, or application of chemical herbicides. In tropical Africa hand weeding remains the most common means of weed control. Blanket fertilizer recommendation rates for durum wheat in Ethiopia are 41 kg N and 26 kg P per ha; additionally 23 kg/ha N can be top-dressed under heavy rain conditions at early growth stages. However, farmers in Ethiopia do not usually give priority to durum wheat when applying commercial fertilizer.

Diseases and pests

The most important diseases of durum wheat in tropical Africa are stem rust (Puccinia graminis) and leaf rust (Puccinia recondita f.sp. tritici, synonym: Puccinia triticina). The use of resistant cultivars is the most effective control measure against these diseases. In cooler regions, stripe rust or yellow rust (Puccinia striiformis) limits durum wheat production, e.g. in the Arsi highlands of Ethiopia.

The most important insect pests in tropical Africa include aphids (which may also transmit viruses), and grasshoppers. The African migratory locust (Locusta migratoria) is a periodic pest that causes crop damage in northern and eastern Ethiopia. The Hessian fly (Mayetiola destructor) has long been an important pest in regions adjacent to the Mediterranean Sea in northern Africa, southern Europe and western Asia. Control of insect pests with commercial insecticides in tropical Africa is rare. Important storage insects in Ethiopia include Sitophilus spp. on whole grains, and Tribolium spp. and Ephestia cautella (synonym: Cadra cautella, flower moth) on wheat flour. Rodents, mainly the black rat (Rattus rattus), also damage stored seeds.

Harvesting

In tropical Africa durum wheat is usually harvested with sickles and rarely by machine. A crop harvested at physiological maturity (grain moisture content 25–35%) must be dried thoroughly before threshing. Wet weather at harvest time can cause serious losses in grain quality because the grain sprouts readily. Plants are stacked or spread out to dry in the sun. Threshing is mostly done by trampling animals.

Yield

Durum wheat yields on farmers’ fields in Ethiopia vary from 800 kg/ha to 2.5 t/ha; mean yield is estimated at less than 1 t/ha. Yields tend to be rather low due to the low application of improved cultivars and optimal production practices, and low levels of fertilizer applied. Yield progress in durum wheat has generally been lower than that in bread wheat. However, durum wheat grain yields of 5–6 t/ha can be obtained with irrigation and the use of improved cultivars and better production practices. Straw yields are equally important in Ethiopia and range from 9–15 t/ha.

Handling after harvest

In tropical Africa, e.g. in Ethiopia, threshed grains of durum wheat are separated from the residues by winnowing. The clean seeds are stored, sold or processed for home consumption. Harvested durum wheat grain should be dried to moisture content of 13–14% for safe storage. High temperatures and moist conditions may result in spoilage. Regular re-drying may be necessary to maintain seed viability, if the seed is not stored in an airtight container.

Genetic resources

The International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria (21,010 accessions) and the International Maize and Wheat Improvement Center (CIMMYT), Mexico City, Mexico (7880 accessions) maintain large germplasm collections of Triticum turgidum. Large germplasm collections are also held in the United States (USDA-ARS National Small Grains Germplasm Research Facility, Aberdeen, Idaho, 42,030 accessions), the Russian Federation (N.I. Vavilov All-Russian Scientific Research Institute of Plant Industry, St. Petersburg, 5580 accessions) and Australia (Australian Winter Cereals Collection, Agricultural Research Centre, Tamworth, New South Wales, 5520 accessions). In tropical Africa the Institute of Biodiversity Conservation (Addis Ababa, Ethiopia) has the largest collection of Triticum turgidum (12,500 accessions). Since Ethiopia is an important centre of diversity of durum wheat, several studies since the 1970s have dealt with the magnitude and structure of Ethiopian durum wheat germplasm using morphological, protein, cytological and molecular markers. While the area of durum wheat has decreased since the 1970s, no drastic changes in the overall diversity are evident.

Breeding

CIMMYT and ICARDA have the international mandate to disseminate durum wheat germplasm to national programmes. In tropical Africa a strong breeding programme has been underway in Ethiopia since 1976. High grain yield and disease resistance, mainly to stem and leaf rusts, have been the major objectives, and recently industrial quality has been included. Genotype × environment interactions in Ethiopia are very high and therefore emphasis has shifted from wide to specific adaptation. Major breeding methods are conventional, and include selection from indigenous landraces and introductions from CIMMYT and ICARDA, and hybridization. Greater success was achieved from the international introductions than from the landrace selections. More than 16 durum wheat cultivars have been officially approved, but their area does not exceed 10% of the total durum wheat area. ‘Boohai’, ‘Foka’, ‘Kilinto’ and ‘Yerer’ are among the most widely sown cultivars.

Linkage-maps of durum wheat have been developed and important QTLs (quantitative trait loci) for grain quality traits have been identified. The developments in wheat molecular genetics and genetic engineering have been relatively slow, especially when compared to other cereals such as rice and maize, due to its ploidy level, size and complexity of its genome, the low level of polymorphism and relatively inefficient transformation systems. Breeding of durum wheat is less advanced than of bread wheat; in addition it has benefited less in wide hybridization and alien gene transfers. Durum wheat is an important component species for bread wheat breeding through formation of synthetic hexaploids, and for the production and development of triticale (× Triticosecale), the hybrid of wheat and rye.

Prospects

In tropical Africa, Ethiopia has the greatest potential for durum wheat because of its favourable growing environments in the cool dry highlands and tradition of growing the crop. There is an increasing demand for quality durum wheat grain by the local pasta industries, which is usually met through import. Breeding programmes have developed cultivars that meet the quality demand by the industry, but in the absence of premium price over the higher-yielding bread wheat cultivars, farmers are losing interest in growing durum wheat. The future trends of durum wheat production, as a result of unfavourable market prices, therefore may seem discouraging. On the other hand, large-scale commercial farmers are entering into durum wheat production to supply the industry, some even replacing bread wheat due mainly to price competition from imported flour. Adaptive research is needed to develop durum wheat that reliably produces 2–3 t/ha in farmers’ fields. More progress is also required in agronomic research, identification of suitable production areas and in establishing an attractive pricing and marketing structure for farmers. The crucial factor is a stable and long-term commitment from the government, the farmers, the private sector (including seed producers) and national research programmes. With this functional partnership in place, Ethiopia could even export quality durum wheat.

Major references

• Bechere, E., Kebede, H. & Belay, G., 2001. Durum wheat in Ethiopia: an old crop in an ancient land. Institute of Biodiversity Conservation and Research, Addis Ababa, Ethiopia. 68 pp.

• Bechere, E., Tesemma, T. & Mitiku, D., 1994. Improved varieties of durum wheat in Ethiopia: releases of 1966–1994. Research Report Series No 2. Debre Zeit Agricultural Research Center, Alemaya University of Agriculture, Debre Zeit, Ethiopia. 32 pp.

• Gebre-Mariam, H., Tanner, D.G. & Hulluka, M. (Editors), 1991. Wheat research in Ethiopia: a historical perspective. Institute of Agricultural Research, Addis Ababa, Ethiopia / International Maize and Wheat Improvement Center, Addis Ababa, Ethiopia. 392 pp.

• Morris, R. & Sears, E.R., 1967. The cytogenetics of wheat and its relatives. In: Quisenberry, K.S. & Reitz, L.P. (Editors). Wheat and wheat improvement. American Society of Agronomy, Madison, Wisconsin, United States. pp. 19–87.

• Scarascia Mugnozza, G.T. (Editor), 1973. Genetics and breeding of durum wheat. University of Bari, Bari, Italy. 696 pp.

• Srivastava, J.P., 1984. Durum wheat: its world status and potential in the Middle East and North Africa. Rachis 3(1): 1–8.

• Gebre-Mariam, H., Tanner, D.G. & Hulluka, M. (Editors), 1991. Wheat research in Ethiopia: a historical perspective. Institute of Agricultural Research, Addis Ababa, Ethiopia / International Maize and Wheat Improvement Center, Addis Ababa, Ethiopia. 392 pp.

• Tesemma, T. & Belay, G., 1991. Aspects of Ethiopian tetraploid wheat with emphasis on durum wheat breeding and genetics. In: Gebre-Mariam, H., Tanner, D.G. & Hulluka, M. (Editors). Wheat research in Ethiopia: a historical perspective. Institute of Agricultural Research, Addis Ababa, Ethiopia / International Maize and Wheat Improvement Center, Addis Ababa, Ethiopia. pp. 47–72.

• van Ginkel, M. & Villareal, R.L., 1996. Triticum L. In: Grubben, G.J.H. & Partohardjono, S. (Editors). Plant Resources of South-East Asia No 10. Cereals. Backhuys Publishers, Leiden, Netherlands. pp. 137–143.

• Wiese, M.V., 1987. Compendium of wheat diseases. 2nd edition. American Phytopathological Society (APS) Press, St. Paul, Minnesota, United States. 112 pp.

Other references

• Alamerew, S., Chebotar, S., Huang, X., Röder, M.S. & Börner, A., 2004. Genetic diversity in Ethiopian hexaploid and tetraploid wheat germplasm assessed by microsatellite markers. Genetic Resources and Crop Evolution 51: 559–567.

• Belay, G., 1997. Genetic variation, breeding potential and cytogenetic profile of Ethiopian tetraploid wheat (Triticum turgidum L.) landraces. PhD thesis, Swedish University of Agricultural Sciences, Uppsala, Sweden. 39 pp.

• Belay, G., Tesemma, T. & Mituku, D., 1993. Variability and correlation studies in durum wheat in Alem-Tena, Ethiopia. Rachis 12(1/2): 38–41.

• Belay, G., Tesemma, T., Mituku, D., Badebo, A. & Bechere, E., 1997. Potential sources of resistance to stripe rust (Puccinia striiformis) in durum wheat. Rachis 16: 70–74.

• Bowden, W.M., 1959. The taxonomy and nomenclature of the wheats, barleys, and ryes and their wild relatives. Canadian Journal of Botany 37: 657–684.

• Curtis, B.C., Rajaram, S. & Gómez Macpherson, H. (Editors), 2002. Bread wheat: improvement and production. Plant Production and Protection Series No 30. FAO, Rome, Italy. 554 pp.

• Elouafi, I. & Nachit, M.M., 2004. A genetic linkage map of the durum × Triticum dicoccoides backcross population based on SSRs and AFLP markers, and QTL analysis for milling traits. Theoretical and Applied Genetics 108(3): 401–413.

• Eticha, F., Bekele, E., Belay, G. & Börner, A., 2005. Phenotypic diversity in tetraploid wheats collected from Bale and Wello regions of Ethiopia. Plant Genetic Resources 3(1): 35–43.

• Feldman, M., Lupton, F.G.H. & Miller, T.E., 1995. Wheats. In: Smartt, J. & Simmonds, N.W. (Editors). Evolution of crop plants. 2nd Edition. Longman, London, United Kingdom. pp. 184 192.

• Gashawbeza, B., Yaekob, A., Zemede, A., Kifetew, J. & Tadesse, T., 2003. Fertilizer N effects on yield and grain quality of durum wheat. Tropical Agriculture (Trinidad) 80(3): 146–151.

• Jauhar, P.P., 2003. Haploid and doubled haploid production in durum wheat by wide hybridization. In: Maluszynski, M., Kasha, K.J., Forster, B.P. & Szarejko, I. (Editors). Doubled haploid production in crop plant: a manual. Kluwer Academic Publishers, Dordrecht, Netherlands. pp. 161–166.

• Mac Key, J., 1966. Species relationships in Triticum. Hereditas (Supplementary volume) 2: 237 276.

• Mohamed, A.I.S., 1999. Performance of durum-wheat genotypes in northern Sudan. Rachis 18(1): 26–30.

• Payne, T.S., Tanner, D.G. & Abdalla, O.S., 1996. Current issues in wheat research and production in eastern, central and southern Africa: changes and challenges. In: Tanner, D.G., Payne, T.S. & Abdalla, O.S. (Editors). The ninth regional wheat workshop for eastern, central and southern Africa. CIMMYT, Addis Ababa, Ethiopia. pp. 1–27.

• Perrino, P., Laghetti, G., d’Antuono, L.F., Al Ajlouni, M., Kanbertay, M., Szabò, A.T. & Hammer, K., 1996. Ecogeographical distribution of hulled wheat species. In: Padulosi, S., Hammer, K. & Heller, J. (Editors). Hulled wheats. Promoting the conservation and use of underutilized and neglected crops. 4. Proceedings of the first international workshop on hulled wheats, 21–22 July 1995, Castelvecchio Pascoli, Tuscany, Italy. IPGRI, Rome, Italy. pp. 101–119.

• Phillips, S., 1995. Poaceae (Gramineae). In: Hedberg, I. & Edwards, S. (Editors). Flora of Ethiopia and Eritrea. Volume 7. Poaceae (Gramineae). The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. 420 pp.

• Tarekegn, A., 1994. Yield potential of rainfed wheat in the central highlands of Ethiopia. MSc Thesis, Alemaya University of Agriculture, Alemaya, Ethiopia. 121 pp.

• Tsegaye, S., 1996. Estimation of outcrossing rate in landraces of tetraploid wheat (Triticum turgidum L.). Plant Breeding 115: 195–197.

• USDA, 2005. USDA national nutrient database for standard reference, release 18. [Internet] U.S. Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory, Beltsville, Maryland, United States. http://www.nal.usda.gov/ fnic/foodcomp. May 2005.

• Walker, D.J. & Boxall, R.A., 1974. An annotated list of the insects associated with stored products in Ethiopia, including notes on mites found in Harar Province. East African Agriculture and Forestry Journal 39: 330–335.

Sources of illustration

• Landwehr, J., 1976. Atlas van de Nederlandse grassen. Thieme, Zutphen, Netherlands. 362 pp.

• Vaughan, J.G. & Geissler, C.A., 1997. The new Oxford book of food plants. Oxford University Press, Oxford, United Kingdom. 239 pp.

Author(s)

• G. Belay, Ethiopian Agricultural Research Organization, Debre Zeit Center, P.O. Box 32, Debre Zeit, Ethiopia

Correct citation of this article

Belay, G., 2006. Triticum turgidum 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.