Tephrosia vogelii: a pesticide of the future for African farming

Global population is expected to reach 9 billion by 2050, increasing pressure on food production (Godfray et al., 2010). Constraintson crop production areparticularly acute in Africa where population growth is greatest and where 80% of all food is produced by small holder farmers on farm sizes of less than one hectare (Stevenson and Belmain, 2016). Crop losses caused by pests and diseases are two major barriers to agriculture that will have major impacts on global food security (Poppy et al., 2014). They are particularly pertinent to small holders who consider insect pests to be the most significant problem over which they can have some control. Current pest control technologies are dependent on synthetic pesticides, but small holders in Africa may overlook them due to cost (Sola et al., 2014) or poor efficacy (Midega et al., 2016). Despite relatively lower use in Africa compared to other parts of the world, synthetic pesticides in Africa have well-documented negative impacts on users due to a poor regard for health and safety of applicators and widespread misuse that increases residues, putting consumers at risk. Negative environmental impacts against beneficial insects are also common, with over and under application exacerbating the development of insecticide resistance. For all these reasons, less harmful and simpler alternatives need to be sought (de Bon et al., 2014; Stevenson and Belmain, 2016).