Breeding Strategies for Adaptation of Pearl Millet and Sorghum to Climate Variability and Change in West Africa

Semi-arid and subhumid West Africa is characterized by high inter-annual rainfall variability, with variable onset of the rainy season, somewhat more predictable endings, and drought or excess water occurrence at any time during the growing season. Climate change is predicted to increase this variability. This article summarizes options for plant breeders to enhance the adaptation of pearl millet (Pennisetum glaucum [L.] R. Br.) and sorghum (Sorghum bicolor [L.] Moench) to climate variability in West Africa. Developing variety types with high degrees of heterozygosity and genetic heterogeneity for adaptation traits helps achieving better individual and population buffering capacity. Traits that potentially enhance adaptive phenotypic plasticity or yield stability in variable climates include photoperiod-sensitive flowering, plastic tillering, flooding tolerance, seedling heat tolerance and phosphorus efficiency. Farmer-participatory dynamic gene pool management using broad-based populations and diverse selection environments is useful to develop new diverse germplasm adapted to specific production constraints including climate variability. For sustainable productivity increase, improved cultivars should respond to farmer-adoptable soil fertility management and water harvesting techniques. Larger-scale, on-farm participatory testing will enable assessments of varietal performance under evolving climatic variability, provide perspective on needs and opportunities and enhance adoption. Strengthening seed systems will be required to achieve sustainable impacts.