Gezira, Al (äl jəzēˈrə) [key], or Al Jazirah äl jäzēˈrä, region, SE Sudan, occupying the tract between the White and Blue Niles south of their convergence at Khartoum. The Arabic word Gezira means "island" or "peninsula."Wad Madani is the region's chief town. The planned development of the region for irrigated cotton cultivation has made it by far Sudan's leading agricultural area. Originally operated by a private company in conjunction with the government, the entire project was nationalized in 1950. The Sennar Dam and the irrigation canals built there since 1925 have put more than 2.5 million acres (1 million hectares) into cultivation. Cotton production was increased in the 1970s, but by the 1990s increases in wheat production had reduced cotton acreage by a third.