"farms called plantations. Plantation economies rely on the export of cash crops as a source of income. Prominent plantation crops included cotton, rubber, sugar cane, tobacco, figs, rice, kapok, sisal, and species in the genus Indigofera, used to produce indigo dye. The longer a crop's harvest period, the more efficient plantations become. Economies of scale are also achieved when the distance to market is long. Plantation crops usually need processing immediately after harvesting. Sugarcane, tea, sisal, and palm oil are most suited to plantations, while coconuts, rubber, and cotton are suitable to a lesser extent."