Perspective on the present state and future usefulness of marama bean (Tylosema esculentum)

Abstract

Recent focus on indigenous knowledge of plant species that have long been consumed by mankind, but not having a prominent place in organized agriculture, has raised the profile of what steps are needed to bring such potentially useful plant species into formal agriculture practice. Many of these orphan plants have been cultivated, albeit usually without much improvement. Tylosema esculentum (marama bean) is unusual; in that, it has not been grown as a crop but only collected from wild stands. The nutritious seeds have been consumed, and other potentially useful products from the marama seeds and tubers have been identified. The marama bean grows under inhospitable environments, particularly hot arid conditions, and, if domesticated, could be grown in environments where there are no high-yielding alternatives. The perspective of this article is to view the current status of the marama bean domestication and the possible pathways to bring this plant into wider agricultural use. The scientific basis for an improved crop yield needs to be coupled with the identification of possible added value characteristics for growers. These include acceptability as a food, possible industrial use, the development and distribution of improved seed, and the recruitment of growers to plant marama as a crop. The authors' international collaboration has already made advances in some of these areas. We discuss the current ongoing developments and existing gaps in moving this plant into formal agriculture, along with a plan for the future developments necessary for marama to provide food security under climate change, particularly in Africa. Even as the process of domestication of marama bean is proceeding, its unusual and potentially useful characteristics will greatly benefit the improvement of other legume crops needed to provide adequate nutrition to about 35% of the world population living in semi-arid to arid regions of the developing world.