Sweetpotato, with a global annual planting area of approximately 9 million ha, is the second most important tropical root crop. It is widely adapted, being grown in more than 110 countries. Early maturing varieties grow in 3-4 months. It is hardy and has multiple uses. Both roots and foliage are edible and provide energy and nutrients in diets. Distinct quality types have different uses, with orange-fleshed sweetpotato being valued for its extremely high provitamin A content, and other types used in varied fresh and processed forms. Sweetpotato is easily bred, as true seed is easily obtained and generation cycles are short. There are five objectives of this review. The first objective is to briefly describe recent production and utilization trends by region; the second is to review knowledge about the origin and genetic nature of sweetpotato; the third is to review selected breeding objectives. The fourth objective is to review advances in understanding of breeding methods, including: (i) generation of seed through polycross nurseries and controlled cross breeding; (ii) a description of a new accelerated breeding approach; (iii) recent efforts to systematically exploit heterosis; and (iv) new approaches of genomic selection. The fifth objective is to provide information about variety releases during the past 20 years in West, East and Southern Africa, South Asia, East and South-east Asia, China and the Pacific.

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Given the importance of cowpea [Vignaunguiculata(L)Walp] in fighting malnutrition and poverty, a socio‐economic assessment of cowpea diversity found on the Ghanaian market was conducted. The objective was to investigate emerging consumer preference for cowpea and make recommendations for the development of tailor‐made varieties. Forty‐seven cowpea accessions were collected from traders interviewed for morphological characterization to ascertain the degree of diversity. Data was subjected to Hierarchical Cluster Analysis using Genstat Discovery Edition 3 software and variations among the cowpea varieties based on the selected seed traits established. Cowpea varieties found on the markets were broadly categorized into foreign and local varieties and usually named after their sources. Foreign Cowpea varieties were very popular on the markets surveyed as reflected in the per cent distribution of respondents by cowpea varieties sold; Niger (52%), Burkina Faso (50%), Togo (46%), Lagos (36%) and Ghana (18–21%). At the trader level, the order of preference for cowpea characteristics was cleanliness (stone free and no dirt), colour (white seed colour), easy to cook, taste, size, less weevil damage, dryness and place of origin ranked in decreasing order of importance. At the consumer level, cleanliness that was also tied to the extent of weevil damage was ranked most important. This was followed by seed colour (preferable white), short cooking time, size and taste. From the sociological perspective, concerns are raised on the impact of past cowpea breeding activities giving the level of competitiveness and market performance of locally improved varieties observed. Recommendation is made for traders and consumers to be considered as relevant actors in all the stages of crop improvement and breeding activities. This is crucial for enhanced small‐holder farmer market access and strengthened food networks in rural economies.

The current study was aimed at identifying mega‐environments in Ghana and evaluating adaptability of superior sweetpotato [Ipomoea batatas (L.) Lam.] genotypes from a targeted breeding effort. Three sets of genotypes were evaluated in multi‐environment trials (MET). Twelve sweetpotato varieties were evaluated across nine environments representing the main agro‐ecological zones in Ghana. MET analysis was conducted using a stage‐wise approach with the genotype × environment (G × E) table of means used as a starting point to model the G × E interaction for sweetpotato yield. Emphasis was given to the genetic correlation matrix used in a second‐order factor analytic model that accommodates heterogeneity of genetic variances across environments. A genotype main effect and G × E interaction of storage root yield explained 82% of the variation in the first principal component, and visualized the genetic variances and discriminating power of each environment and the genetic correlation between the environments. Two mega‐environments, corresponding to northern and southern trial sites, were delineated. Six breeding lines selected from the south and eight breeding lines selected from the north were tested and compared to two common check clones at five locations in Ghana. A Finlay–Wilkinson stability analysis resulted in stable performances within the target mega‐environment from which the genotypes were selected, but predominantly without adaptation to the other region. Our results provide a strong rationale for running separate programs to allow for faster genetic progress in each of these two major West African mega‐environments by selecting for specific and broad adaptation.