Other important cash crops and exports include copra, cacao and palm oil. In 2017 317,682 tons of coconuts were harvested making the country the 18th ranked producer of coconuts worldwide, and 24% of the exports corresponded to copra. Cocoa beans are mainly grown on the islands Guadalcanal, Makira and Malaita. In 2017 4,940 tons of cocoa beans were harvested making the Solomon Islands the 27th ranked producer of cocoa worldwide. Growth of production and export of copra and cacao, however, is hampered by old age of most coconut and cacao trees. In 2017 285,721 tons of palm oil were produced, making Solomon Islands the 24th ranked producer of palm oil worldwide. The agriculture on the Solomon Islands is hampered by a very severe lack of agricultural machines.