Neglected and Under-used Crop Species (NUCS) – Crops of the future?

The agricultural systems of today seem to promote monoculture, or at least very low biodiversity of crops in a given area to reduce costs and maintenance (Chivenge et al. 2015).  There has been a decline in ‘traditional’ crops in Africa and an increase in their genetic erosion due to their replacement by major crops and due to the ignorance of NUCS in research and conservation (Dansi et al. 2012). However, research has shown that NUCS have the potential to address the current food security insecurity issues in Sub-Saharan Africa due to their high adaptability to low input agricultural systems as well as high nutritional values. 

There is currently no agreed definition as to what NUCS are, but Chivenge et al. (2015) have defined them as ‘crops that have not been previously classified as major crops, have previously been under-researched, currently occupy low levels of utilisation and are mainly confined to smallholder farming areas’ (Chivenge et al. 2015: 5688). NUCS were more important to subsistence farmers in the past and were grown as part of their diet or as a back up or alternative when the main crop failed, yet there is little written information regarding NUCS as information is trapped in indigenous knowledge systems (Nyadanu et al. 2016). Now, NUCS have been replaced by major staple crops that are in high demand, which are not that well-adapted to local conditions.  Promoting  the growth of NUCS and hence agro-biodiversity is vital so that agricultural systems can grow to become more climate change resilient by improving ‘nutrient cycling, carbon sequestration, soil erosion control, reduction of greenhouse gas emissions and control of hydrological processes’, and hence improve food security (Chivenge et al. 2015: 5686).  Sub-Saharan Africa’s development agenda consists of improving agricultural productivity, yet the plans and strategies being implemented are only concentrated on a small variety of crops.

NUCS include: 

• Sweet potatoes
• Wild melon
• Taro
• Bambara groundnut
• Wild mustard

These crops, as well as other NUCS are tolerant to biotic and abiotic stresses, including drought, and require minimal inputs, relative to other major crops. A plant has the ability to survive droughts if they have a short growing season, which means that they can finish their growth cycle before conditions of water stress are felt. Drought tolerance also occurs if water loss from the plant is reduced whilst root uptake is maintained. Water loss can be minimized through reducing plant height, leaf area and the number of leaves (Mitchell et al. 1998).  For example, wild watermelon, native to southern Africa, is believed to be drought tolerant as they maintain their photosynthetic mechanisms even when there is a lack of water (Miyake and Yokota 2000). Not only was it traditionally cultivated due to its drought resistance, but also due to its nutritional benefits and wider uses. Watermelon rind can be used in pickles, can be a source of pectin and the seeds are high in protein.

Watermelon growing in the Sahara (Source)

It is a shame that the expectations of today’s agricultural supply systems force farmers to reduce their agro-biodiversity without regards to indigenous lifestyles and nutritional values. The promotion of NUCS can only be successful if there is a greater respect for indigenous knowledge and the participation of local communities in agricultural strategic planning.

Chivenge et al. (2015) and Dansi et al. (2016) suggest that there needs to be an increase in the research on NUCS which will enable them to be promoted in the future, but I think that the lack of scientific knowledge is not the only limiting factor to the widespread growth of NUCS. Personally, I feel that the value of NUCS needs to be communicated to farmers better, who are more concerned about fulfilling the demand of external markets in order to make more profits. Nyadanu et al. (2016) claim that value can be added to these crops by conveying their medicinal uses, religious associations and traditional uses, and in many instances, women are mostly associated with cultivating NUCS as they have many household uses. So women may be the target when attempting to create a strong value chain for NUCS.