Agriculture is the main economic activity, involving about 71% of the economically active population. An estimated 8% of the land is engaged in crop production. The island of Bioko has year-round rainfall, and the prevailing economic activity is cocoa cultivation. In Río Muni (on mainland Africa), where 80% of the population lives, food crops are the dominant economic activity, and cash crop cultivation is secondary. Agriculture (including forestry and fishing) accounts for about 50% of GDP and 60% of exports. The main food crop is cassava, of which 49,000 tons were produced in 1998. Sweet potatoes are the second-largest food crop, with 45,000 tons in 1999, followed by bananas (20,000 tons).
Before independence, the main cash crops were cocoa, coffee, and palm kernels for palm oil. Guinean cocoa, of excellent quality, had an annual production of 38,000 tons in 1967. However, production experienced a sharp drop in the 1970s, falling to 4,512 tons in 1980. In 1999, production was estimated at 6,000 tons. Coffee of comparatively poor quality is grown in northern Río Muni, along the Cameroon border. The preindependence production of 8,959 tons in 1967 fell to 500 tons in 1978; the decline was mainly caused by forcible transfer of coffee farmers to the Bioko cocoa plantations. Coffee production was an estimated 4,000 tons in 1999. Actual cocoa and coffee production is higher, but official figures do not take into account quantities smuggled abroad rather than delivered to state marketing agencies.