African Journal of Biotechnology Vol. 6 (4), pp. 325-334, 19 February 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Assessing the biological potential of N₂-fixing Leguminosae in Botswana for increased crop yields and commercial exploitation

Flora Pule-Meuelenberg¹ and Felix D. Dakora²

¹Faculty of Applied Science and ²Research and Technology Promotion, Cape Peninsula University of Technology, P.O. Box 652, Cape Town, South Africa.

*Corresponding authors E-mail: dakoraf@cput.ac.za. Tel: +27 21 4603878. Fax: +27 21 4603887.

Accepted 18 October, 2005

The Leguminosae are a major source of food, fodder, timber, phytochemicals, phytomedicine, nutriceuticals and N fertility in Botswana. Although the country is beset by drought as a result of low rainfall (150 – 650 mm per year) and high potential evapotranspiration, the Leguminosae appear adapted to this low-nutrient environment. Conducting field inoculation trials with infective rhizobia and selecting legume genotypes or host/strain combinations for increased plant growth would help identify superior symbiotic performers under the environmental stress conditions of Botswana. Thus, selecting high N₂-fixing legume genotypes has the potential to overcome low soil fertility as a production constraint in Botswana, and increase fodder and grain production to support the growing local livestock and wildlife industries. Additionally, identifying native rhizobia in Botswana that alleviate water stress when in symbioses with legumes could be a first step to tapping the biological potential of the Leguminosae for increased yields in drier environments.

Keywords: Leguminosae, N₂ fixation, crop yields, Botswana, rhizobia.