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close this bookGATE - 4/93 - Botswana: Rural Industrial Development (GTZ GATE, 1993, 48 p.)
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View the documentHow to initiate rural industrial development
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View the documentAn innovation benefits women: The Sorghum Milling Project

An innovation benefits women: The Sorghum Milling Project

by Jackson Maleke

In 1979 the Rural Industries Innovation Centre (RIIC) developed the sorghum dehuller, as a means of reducing the workload of women in particular. The new sorghum milling technology has meanwhile been disseminated not only throughout Botswana, but also in ten other African states.

Historically, sorghum processing in Botswana is done by way of traditional hand stamping in a mortar with a pestle, a task that has largely occupied much of women's time in rural areas, who have huther to served as principal actors on household food preparation chores.

The call for an easier way to process sorghum was answered following a 1977 needs assessment survey conducted by the Rural Industries Innovation Centre (RIIC) in the Southern District of Botswana. The information gained from this survey helped guide the RIIC to develop the sorghum dehuller in 1979 in order to alleviate the pounding constraint. The evolution of the sorghum dehuller has ushered in a new era for women in rural are as, and in turn allowed them to spend 41% amount of their time on productive economic activities, which would otherwise have not taken place.

The technology

The RIIC machine is a dry abrasive disc dehuller, adapted from the barley thresher modified by the Prairie Research Laboratory (PRL) in Canada. The principle employed is that of progressive abrasion of the outer layers of grains throughout the length of the dehuller barrel.

Significant technical advances on the dehuller contributed by RIIC include its aspiration system and trap door, which facilitate both batch processing and continuous production. As a direct result of these advances, the dehuller is capable of processing up to 600 kg of grain per hour. It requires either a 5.5 kilowatt three-phase or a ten horsepower diesel engine.

The dehuller operates alongside a hammer mill, which crushes the decorticated grains into the end product.

Continuous flow operation is ensured through a complimentary combination of these two technologies: the dehuller and the hammer mill. In addition to sorghum, the dehuller can be adapted to process millet, cowpeas and maize.

Two types of production services are rendered in the milling industry nationwide. These are service and commercial milling.

Service Milling

Grain bags are directly funneled by customers to the milling industry, whereupon milling is performed with charge per kilogramme imposed, after the overall weight has been determined. The dehulling process is normally performed to extract the bran, which has a bitter tannin taste. Bran, which is collected in bags is extracted at the rate of 12-15% of the total grain content. Subsequently, the decorticated grains are pulverized in a second process with a hammer mill.

Service milling will require a minimum of two to three unskilled labourers, one operating the dehuller and hammermill, while the other concentrates on weighing the bags for processing.

Commercial milling

For this purpose, the milling industry directly purchase several bags of grains, process them in a continuous flow, and pack the flour in plastic bags for sale. In a continuous process, the weighed grain is processed using the same equipment as for the service milling and the labour requirements are the same. However, two or so additional unskilled labour are normally required to operate the packaging unit, where weighing of the flour as well as sealing of bags is required.

The flour produced within this milling category, which is then sold to individuals and retailing outlets is a fine, nutritious product without a bitter tannin taste.

The development and dissemination of the RIIC sorghum milling technology has instigated the evolution of a decentralized milling operation in both rural and peri-urban areas nationwide. Following the emergence of this versatile and "economically ebullient" technology in 1979, a total of 63 individual and institutional milling operations have been established in Botswana. The net result of this industry has been and continues to be the creation of jobs, which ensures filtration of cash into the rural economic sector to improve living standards.

Export breakthrough

Employment figures indicate that 45% of the labour force in the milling industry is female, with the majority of them either owning the operations or involved in key management positions.

The RIIC sorghum milling technology has not only been disseminated in Botswana but in ten other African countries: Lesotho, Malawi, Mali, Namibia, Senegal, South Africa, Swaziland, Tanzania, Zambia and Zimbabwe. In 1986, the dehuller was awarded first prize among 26 competitors in a development technology competition mounted for technologies from developing countries in Genoa, Italy. The success gained from this competition, has in many ways accentuated the dehuller's takeup capability, both locally and regionally as well.

RIIC's concerted initiative in simplifying the dehuller for local use in rural areas and in other developing countries, signifies a major breakthrough in translating good intentions into actual tangible results.


One of RIIC's most successful innovations is the sorghum dehuller. developed in 1979. This machine, intended primarily as a labour-saving device for women, was awarded first prize in a development technology competition in Genoa, Italy, in 1986 Combined with the hammer mill, the technology has directly contributed to the establishment of many private milling centres throughout Botswana. The net result has been the creation of many jobs for locals. The sorghum milling technology developed by RIIC is meanwhile being exported to ten other African countries. The author describes how the sorghum dehuller works and the social impact of this development.


L'une des innovations les plus reussies du RIIC est le decortiqueur de mil developpe en 1979. Cette machine, essentiellement destinee a faciliter le travail des femmes, a ete primee en 1986 lors d'un concours de technologies du developpement organise a Genes en Italie. Le decortiqueur peut etre exploite commercialement ou a des fins de prestation de senices. Associee a un moulin a marteaux, cette technologie a directement contribue a l'etablissement de nombreux centres de mouture prives au Botswana et indirectement a la creation de nombreux emplois locaux. Cette technologie de mouture du mil, developpee par RIIC, est entre temps exportee dans dix pays africains.


Una de las innovaciones mas exitosas del RIIC es la descascadora de sorgo que fue desarrollada en 1979. La maquina, que pretendia facilitarles el trabajo sobre todo a las mujeres, obtuvo el primer premio en 1986 en un concurso de desarrollo tecnologico que tuvo luger en Genova (Italia). La descascadora puede utilizarse pare operaciones comerciales de senicio. Combinada con el molino de martillos, la tecnologia ha contribuido directamente a establecer numerosos molinos privados en toda Botswana. Gracias a ello se hen creado numerosos puestos de trabajo pare los habitantes locales. Entretanto, la tecnica de molido de sorgo desarrollada por el RIIC es exportada tambien a otros diez paises africanos.