Western Cotton Research Laboratory Conveyance Act - Directs the Secretary of Agriculture, after the completion of Agricultural Research Service operations at the Western Cotton Research Laboratory located at 4135 East Broadway Road in Phoenix, Arizona, to convey, without consideration, to the Arizona Cotton Growers Association and to Supima (the successor of the Arizona Cotton Planting Seed Distributors) all right, title, and interest of the United States in and to the real property at that location, including improvements thereon, which was originally conveyed to the United States by the Arizona Cotton Growers Association and the Arizona Cotton Planting Seed Distributors in 1966 for nominal consideration.