It1. Introduction

Taro (Cocoyam) [Colocasia esculenta (L.) Schott] is an important tropical root crop grown purposely for its starchy corms or underground stem [1]. It is regarded as one of the most important staple crops in the Pacific Islands, Asia and Africa [1,2,3,4]. It is one of the oldest world’s food crops believed to have been first domesticated in Southeast Asia before its eventual spread to other parts of the world [5,6]. The two most commonly cultivated species of Taro (Colocasia esculenta and Xanthosoma sagittifolium) belong to the Araceae family and are extensively cultivated in Africa.

Taro is an herbaceous monocotyledonous plant of 1–2 m height. The plant consists of central corm (below the soil surface) making the leaves grow upwards, roots grown downwards, while cormels, daughter corms and runners (stolons) grow laterally. The root system is fibrous and lies mainly at a depth of up to one meter of soil [3,7].

In most Pacific Island countries (PICs) where taro is widely cultivated and consumed, two species of Colocasia are recognized. They are C. esculenta var. esculenta, commonly called dasheen, and C. esculenta var. antiquorum, often referred to as eddoe [3,8]. The dasheen variety possesses large central corms, with suckers and/or stolons, while eddoes have somewhat small central corm and a large number of smaller cormels [3,9,10].

In Africa, Taro is commonly produced by smallholder, resource-limited and mostly female farmers [3]. Taro ranks third in importance, after cassava and yam, among the class of root and tuber crops cultivated and consumed in most African countries [3]. The crop is underutilized in the areas of export, human consumption, industrial uses, nutritional and other health benefits in Africa. Thus, the objective of this review is to provide a critical assessment of the leading players in the taro sub-sector globally and continentally with the most recent datasets useful for policy intervention and planning. Also, this study explores the nutritional, health and economic benefits of taro highlighting the role it can play in enhancing sustainable livelihoods especially in Africa.

2. Taro [Colocasia esculenta (L.) Schott] in Africa

In many parts of the world, (especially, African countries), roots and tubers such as cassava (Manihot esculenta), sweet potato (Ipoemea batatas), yam (Dioscorea sp), and cocoyam (Colocasia esculenta and Xanthosoma sagittifolium), are important staple crops commonly cultivated by smallholder farmers and used as food security and income crops [11,44]. Taro production in Africa (especially SSA) is commonly by smallholder, resource-limited and mostly female farmers [3]. However, the crop is mostly referred to as “poor man’s crop” because its consumption is mainly by the low income households in the society [3]. As mentioned above, Africa contributed to over 70% of global taro production consistently in the past two decades and accounted for about 76 percent of world share in 2000 but, witnessed a slight decline in production levels in two decades attaining 72.27% (7.6 million tonnes) share of world total production in 2019 (Table 10) [11]. Despite the global recognition of taro production in Africa, the crop has suffered serious neglect, receiving little attention from agricultural researchers and government policymakers [3,43,44,45,46].

The world is faced with enormous task of providing sufficient food for over seven billion people, with 690 million people suffering from hunger globally, Africa region accounted for 73 million out of the 135 million people suffering from acute food insecurity in 2019 [47,48,49,50,51,52,53]. Hunger and malnutrition continue to escalate as the world’s food system is being threatened by the emergence of COVID-19 pandemic in December 2019. The attendant total and partial lockdowns in many countries has led to increased level of hunger and food insecurity. The situation in Africa is the one referred to as “a crisis within a crisis” with very high prevalence of hunger and malnutrition in most Africa countries. African governments need to intensify efforts in boosting agricultural production and keeping the food value chain active in order to stem the tide of hunger and food insecurity in the continent [54,55,56,57,58,59,60].

However, one of the means of reducing the level of hunger and protein-energy malnutrition in Africa (especially SSA) is through increased production and consumption of indigenous staples of high energy content such as taro [61,62]. Taro is recognized as a cheaper yam substitute, notably during period of food scarcity (hunger season) among many households in SSA (especially Ghana and Nigeria) and its production remained an integral part of many smallholder farming households in many parts of West and Central African countries [3]. It is worthy of note that, most of the output that placed Nigeria as number one taro producer globally and other high producing African countries like Cameroon, Ghana, Madagascar and Burundi (Figure 3) are carried out by smallholder rural farmers employing primitive technology and traditional farming practices with limited intensive management system [3,11]. Taro leaves and tubers possess excellent nutraceutical and healing properties. Thus, its increased production and consumption should be encouraged because of these properties in addition to its usefulness as a food security staple.

5.1. Recent Taro Productivity and Yield Potential in Africa

Figure 4. Declining African region Taro (Cocoyam) yield with trend line (2000–2019), Source: Authors’ graph using data from FAOSTAT 2021 [11]. The vertical lines are the average of Taro and the horizontal axis represents the year of production.

Figure 5. Nigeria’s declining Taro yield with trend line (2000–2019); Source: Authors’ graph using data from FAOSTAT 2021 [11]. Note: The dotted line is the trend line; the solid line is the declining Nigeria Taro yield.

5.2. Taro Trade Potentials in Africa

This entry is adapted from the peer-reviewed paper 10.3390/su13084483