Biology, production constraints and uses of Cyperus exculentus L. (neglected and underutilized crop species), implication for valorization: a review.
Food security relies mainly on a few major crop species such as wheat, maize and rice, cassava and yam. Many of the cultivated plant species such as Tigernut (Cyperus exculentus) are still considered invasive plants and are neglected and underutilized. However, they may play a crucial role in food security, nutrition, and income generation among poor rural people. In the perspective to valorization of the species, this systematic review aimed at identifying the biology, production constraints and uses of tigernut for future research directions. Extensive searches were carried out and studies were screened and extracted using established systematic review methods. A total of 175 papers from Africa, America, Asia, and Europe met the inclusion criteria. Thematic synthesis was used to synthesis data and findings are presented under three framework aspects. Approximately 52% of the studies were undertaken in Europe while 21.71% were undertaken in Africa. Most of the papers reviewed for the study were published between [2010 and 2015]. The results highlighted the critical research gaps in ecology, plant demography, genetic diversity using SSR makers, genomics and evolutionary biology. Further, production constraints and solution approaches for the conservation and promotion of the species were the other gaps identified in the reviewed studies. Production constraints were specifically related to the insufficient mineral fertilizers, difficult in harvesting and post-harvest losses. Tigernut is used in more fields such as food, medicinal, cosmetic, biofuel and fishing and fish breeding. Such investigations would help in decision-making and elaboration of breeding strategies, and advancing steps towards sustainable use and the valorization of the species.