PROTA, Introduction to Cereals and pulses

PROTA 1, 2006. Plant Resources of Tropical Africa. vol. 1. Cereals and pulses. ed. by M. Brink & G. Belay. Wageningen, PROTA Foundation - Backhuys - CTA. 298 p.

Choice of species

PROTA 1: ‘Cereals and pulses’ describes the cultivated and wild species of tropical Africa used as a cereal or pulse. Cereals can be defined as grasses (family Poaceae) of which the grain is used for food; they may be cultivated or the grain is collected from wild plants (‘wild cereals’). Three cereals that are not grasses (‘pseudo-cereals’) have also been included in this volume: Amaranthus caudatus L. (grain amaranth), Fagopyrum esculentum Moench (buckwheat) and Limeum obovatum Vicary. Pulses can be defined as leguminous species (members of the families Papilionaceae, Caesalpiniaceae or Mimosaceae, often considered as one family Leguminosae) producing edible mature seeds. Pulses may also be cultivated or collected from the wild.

Some species are only used as a cereal or pulse, but most have several uses. PROTA normally assigns a single primary use and, where relevant, one or more secondary uses to all plant species used in Africa. PROTA 1: ‘Cereals and pulses’ comprises only accounts of species whose primary use is as a cereal or pulse. The primary use of pigeon pea (Cajanus cajan (L.) Millsp.) is as a pulse, and thus it is treated in PROTA 1, but it has various secondary uses, e.g. the immature seeds and pods are eaten as a vegetable, the seeds and the by-products of dhal production are used as animal feed, the vegetative parts are used as fodder, the stems and branches are used for basketry, thatching, fencing and as fuel, from various plant parts traditional medicines are prepared, and the plants are grown as a shade crop or cover crop and in hedges and windbreaks. Winged bean (Psophocarpus tetragonolobus (L.) DC.), on the other hand, is eaten as a pulse, but its primary use is its immature pods being eaten as a vegetable, and consequently winged bean is described in PROTA 2: ‘Vegetables’.

Species that are used as a cereal or pulse in tropical Africa but have another primary use are listed after the primary use cereals and pulses, and are fully described in other commodity groups. Some well-known species included in this list are: kodo millet (Paspalum scrobiculatum L.), lablab (Lablab purpureus (L.) Sweet) and winged bean (Psophocarpus tetragonolobus (L.) DC.).

Six species are treated which have two primary uses, including use as cereal or pulse, and consequently will be described in two commodity groups. These species are Arachis hypogaea L. (also in PROTA 14: ‘Vegetable oils’), Glycine max (L.) Merr. (also in PROTA 14: ‘Vegetable oils’), Phaseolus vulgaris L. (also in PROTA 2 ‘Vegetables’), Pisum sativum L. (also in PROTA 2 ‘Vegetables’), Vigna unguiculata (L.) Walp. (also in PROTA 2 ‘Vegetables’), and Sorghum bicolor (L.) Moench (also in PROTA 3: ‘Dyes and tannins’).

In PROTA 1: ‘Cereals and pulses’ comprehensive descriptions are given of 35 important species (15 cereals, 19 pulses and 1 pseudo-cereal). These major cereals and pulses comprise most cultivated species, but also several wild or partly domesticated ones. The accounts are presented in a detailed format and illustrated with a line drawing and a distribution map. In addition, accounts of 38 species of minor importance (22 cereals, 14 pulses and 2 pseudo-cereals) are given. Because information on these species is often scanty, these accounts are in a simplified format. For another 9 species (5 cereals and 4 pulses) the information was too scarce to justify an individual treatment and they have only been mentioned in the accounts of related species.

Plant names

Family: Apart from the classic family name, the family name in accordance with the Angiosperm Phylogeny Group (APG) classification is also given where it differs from the classic name.

Synonyms: Only the most commonly used synonyms and those that may cause confusion are mentioned.

Vernacular names: Only names in official languages of regional importance in Africa are included: English, French, Portuguese and Swahili. It is beyond the scope of PROTA to give an extensive account of the names of a species in all languages spoken in its area of distribution. Checking names would require extensive fieldwork by specialists. Although regional forms of Arabic are spoken in several countries in Africa, the number of African plant species that have a name in written, classical Arabic is limited. Arabic names are therefore omitted. Names of plant products are mentioned under the heading ‘Uses’.

Origin and geographic distribution

To avoid long lists of countries in the text, a distribution map is added for major species. The map indicates in which countries a species has been recorded, either wild or planted. For many species, however, these maps are incomplete because they are prepared on the basis of published information, the quantity and quality of which varies greatly from species to species. This is especially the case for wild species which are not or incompletely covered by the regional African floras, and for cultivated species which are only planted on a small scale (e.g. in home gardens). For some countries (e.g. Central African Republic, Chad, Sudan, Angola) there is comparatively little information in the literature. Sometimes they are not covered by recent regional or national floras and although species may be present there, this cannot be demonstrated or confirmed.

Properties

The food value of the cereals and pulses is mentioned in the species accounts. The analytical method used to determine the various elements of the nutritional composition considerably influences the values found. For this reason a few standard sources were used wherever possible and the sources are mentioned in the text. These sources are: the USDA Nutrient database for standard reference; McCance & Widdowson’s The composition of foods; FAO Food composition table for use in Africa.

Apart from nutrients, this section includes other properties relevant to the respective uses.

Description

A morphological characterization of the species is given. The description is in ‘telegram’ style and uses botanical terms. Providing a description for the general public is difficult as more generally understood terms often lack the accuracy required in a botanical description. A line drawing is added for all major and some lesser-known species to complement and visualize the description.

Management

Descriptions of husbandry methods including fertilizer application, irrigation, and pest and disease control measures are given under ‘Management’ and under ‘Diseases and pests’. These reflect actual practices or generalized recommendations, opting for a broad overview but without detailed recommendations adapted to the widely varying local conditions encountered by farmers. Recommendations on chemical control of pests and diseases are merely indicative and local regulations should be given precedence. PROTA will participate in the preparation of derived materials for extension and education, for which the texts in this volume provide a basis, but to which specific local information will be added.

Genetic resources

The genetic diversity of many plant species in Africa is being eroded, sometimes at an alarming rate, as a consequence of habitat destruction and overexploitation. The replacement of landraces of cultivated species by modern cultivars marketed by seed companies is another cause of genetic erosion. Reviews are given of possible threats for plant species and of the diversity within species. Information on ex-situ germplasm collections is mostly extracted from publications of the International Plant Genetic Resources Institute (IPGRI).

References

The main objective of the list of references given is to guide readers to additional information; it is not intended to be complete or exhaustive. Authors and editors have selected two categories of references; ‘major references’ are limited to 10 references (5 for minor species), the number of ‘other references’ is limited to 20 (10 for minor species). The references listed include those used in writing the account. Where the internet was used, the website and date are cited.

Editors

• M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
• G. Belay, Ethiopian Agricultural Research Organization, Debre Zeit Center, P.O. Box 32, Debre Zeit, Ethiopia

Associate editors

• J.M.J. de Wet, Department of Crop Sciences, Urbana-Champaign, Turner Hall, 1102 South Goodwin Avenue, Urbana, IL 61801, United States
• O.T. Edje, Faculty of Agriculture, University of Swaziland, P.O. Luyengo, Luyengo, Swaziland
• E. Westphal, Ritzema Bosweg 13, 6706 BB Wageningen, Netherlands

General editors

• R.H.M.J. Lemmens, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
• L.P.A. Oyen, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Editeur des photos

• A. de Ruijter, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands