Challenge of Virus Disease Threats to Ensuring Sustained Uptake of Vitamin-A-Rich Sweetpotato in Africa

Orange-fleshed sweetpotatoes (OFSP) are a rich source of pro-vitamin A and can alleviate vitamin A deficiency in the developing world. In Africa, traditional varieties have been almost exclusively white-fleshed and introduction and breeding of orange-fleshed varieties into Africa has been severely hampered by virus diseases to which many varieties are susceptible. Breeding progress to generate resistant varieties has been slow due to rare and recessive occurrence of resistance in breeding populations. Production of virus-free seed is complicated by the fact that most sweetpotato viruses show no or only limited symptoms and very low virus concentrations when infected by individual viruses, making them difficult to detect. Even single infections can lead to significant yield losses, but when they combine severe disease complexes are generated, which can lead to total crop failure. Significant efforts have been made in characterizing and understanding virus interactions in sweetpotato over the last two decades to address this challenge; they are reviewed in this chapter. We also review the state of the art in detection of viruses in support of seed systems and breeding. We conclude with recommendations for the most urgent future research directions needed to address virus problems in sweetpotatoes.

Plantwise: A Knowledge and Intelligence Tool for Food Security through Crop Protection

Food security continues to be significantly impacted by a growing world population, changing climate, increasing food prices and environmental burden. One of the key challenges in reducing crop losses due to pests and diseases is timely delivery of appropriate, actionable extension advice to farmers. Information and communication technology (ICT) has the potential to improve services that connect smallholder farmers to new resources and information, helping to build their knowledge and ultimately improve their livelihoods. Such ICT-driven services have seen rapid growth over the past few years, and CABI has been harnessing this technology in several programmes. This chapter provides insight into digital interventions of the global, CABI-led programme, Plantwise, which aims to assist stakeholders in developing countries to improve their plant health systems by strengthening linkages among all actors involved, so that they can prevent and manage pest outbreaks more effectively. An overview of digital interventions piloted and tested under the umbrella of the Plantwise programme is illustrated with selected case studies. Interventions include pest diagnosis and management advice delivered via a website, plant health data collection, using a customized mobile application, and educational simulation games for ongoing support.