Which country is the largest producer of cowpea?

Could you tell me which country takes the lead in the production of cowpeas? It's intriguing to know which nation dominates in this agricultural sector, especially given the widespread use and nutritional value of cowpeas. Is there a particular region or climate that favors their cultivation, contributing to this country's status as the largest producer? I'm curious to learn more about the agricultural practices and economic impact of cowpea production in this leading nation.