Plantation agriculture has long dominated the economy of the islands. In 1998, there were 39,000 ha (96,400 acres) of farmland planted with permanent crops and just 2,000 ha (4,900 acres) planted with seasonal crops. Before nationalization in 1975, private companies owned more than 80% of the arable land. Their plantations were managed by São Tomé mestiços, Cape Verdeans, and São Tomé Europeans. The rest of the arable land was owned by about 11,000 small proprietors. The nationalization law limited the private holdings to 100 hectares (247 acres) and reorganized 29 plantations into 15 state companies. In 1985, however, the government began legally recognizing the right of individual families to cultivate land within the state plantations. The two largest plantations were leased to European management in 1986.
A variety of microclimates enables the cultivation of diverse tropical crops, but soils are especially suited for cocoa (introduced from Brazil in the late 19th century), which is the major export crop. About half of all cultivated land is used for cocoa production. Labor disruptions, a reduced workweek, inadequate investment in repair and maintenance, and the use of worktime to conduct management and cooperative training programs combined to lower the cocoa output from 10,000 tons in 1975 to 3,900 tons in 1987. Production of cocoa was about 4,000 tons in 1999. Cocoa exports account for about 80% of export earnings. Copra is the second most important crop; production in 1999 totaled about 1,000 tons. Other agricultural products in 1999 were palm kernels, 2,000 tons; bananas, 38,000 tons; cassava, 5,000 tons; and coconuts, 28,000 tons.
Since 1990, economic policy has been driven by a World Bank and IMF-sponsored structural adjustment program aimed at diminishing the dependence on cocoa exports and food imports. The program called for fundamental land reform and accompanying measures to stimulate cultivation of food crops for local consumption.