No abstract

Until recently, there has been little commercial sale of vegetatively propagated crop seed, except for potatoes (Solanum tuberosum). This is especially true in developing countries. However, a formal, commercial seed sector for cassava (Manihot esculenta) is emerging in Nigeria. In 2016, a project, Building an Economically Sustainable Integrated Cassava Seed System in Nigeria (BASICS), started to encourage village farmers to certify and sell cassava seed. A questionnaire survey of 30 cassava entrepreneurs across Nigeria in 2019 included some of those village-based growers as well as larger producers, including some who certified their planting material. In the long run, if there is a consistent demand for certified cassava seed, medium-sized producers may be able to satisfy some of that demand, especially if they have continued programmatic support; otherwise, these budding seed entrepreneurs may close down.

Cassava is an important crop in sub-Saharan Africa for food security, income generation, and industrial development. Business-oriented production systems require reliable supplies of high-quality seed. Major initiatives in Nigeria and Tanzania have sought to establish sustainable cassava seed systems. These include the deployment of new technologies for early generation seed (EGS) production; the promotion of new high-yielding and disease-resistant varieties; the updating of government seed policy to facilitate enabling certification guidelines; the application of ICT tools, Seed Tracker and Nuru AI, to simplify seed system management; and the establishment of networks of cassava seed entrepreneurs (CSEs). CSEs have been able to make profits in both Nigeria (US$ 551–988/ha) and Tanzania (US$ 1,000 1,500/ha). In Nigeria, the critical demand driver for cassava seed businesses is the provision of new varieties. Contrastingly, in Tanzania, high incidences of cassava brown streak disease mean that there is a strong demand for the provision of healthy seed that has been certified by regulators. These models for sustainable cassava seed system development offer great promise for scaling to other cassava-producing countries in Africa where there is strong government support for the commercialization of the cassava sector.

Danish children find new bacteria One of the worlds' largest citizenscience experiments has led to the rapid discovery of ten new bacterial species in Denmark. About 25,000 schoolchildren aged 10-16 years found these Lactobacillus species after analysing some 11,000 plant samples from urban and rural ecosystems (see go.nature. com/2sq5muw). By comparison, Danish researchers find an average of just one new bacterial species per year. Lactobacillus is a beneficial group of bacteria that has been used for food preservation for thousands of years (M. Bernardeau et al. FEMS Microbiol. Rev. 30, 487-513; 2006). The study was spearheaded by the biotechnology company Novozymes near Copenhagen, and its updated biobank is now open to researchers around the world, offering fresh opportunities for industrial and drug development. Children are a large but untapped source of citizen scientists (see also Nature 562, 480-482; 2018). Moreover, they will form the next generation of scientists.

The CGIAR Research Program on Roots, Tubers and Bananas (RTB) is a partnership collaboration led by the International Potato Center implemented jointly with the Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT), the International Institute of Tropical Agriculture (IITA), and the Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), that includes a growing number of research and development partners. RTB brings together research on its mandate crops: bananas and plantains, cassava, potato, sweetpotato, yams, and minor roots and tubers, to improve nutrition and food security and foster greater gender equity especially among some of the world's poorest and most vulnerable populations.