Cowpea ( Vigna unguiculata (L.) Walp.) is the most important grain legume in sub-Saharan Africa where it provides a significant source of human nutrition and animal fodder to millions of low-input farmers. While adapted to a wide range of soils and generally considered climate resilient due to its drought and heat tolerance, cowpea yields are suboptimal throughout its main growing region because of numerous abiotic and biotic...