What crop was a major contributor to the rise in population of central Africa around 1000 C.E.?

The introduction of the banana, particularly the East African Highland banana, was a major contributor to the rise in population in central Africa around 1000 C.E. This crop provided a reliable and nutritious food source, which supported larger communities and improved health. Its cultivation helped to sustain agricultural societies, leading to population growth and the development of trade networks in the region.