More significantly, the 1989 revolution caused many donors in Europe, the U.S., and Canada to suspend official development assistance, but not humanitarian aid. However, as Sudan became the world's largest debtor to the World Bank and International Monetary Fund by 1993, its relationship with the international financial institutions soured in the mid-1990s and has yet to be fully rehabilitated. The government fell out of compliance with an IMF standby program and accumulated substantial arrearages on repurchase obligations. A 4-year economic reform plan was announced in 1988 but was not pursued. An economic reform plan was announced in 1989 and began implementing a 3-year economic restructuring program designed to reduce the public sector deficit, end subsidies, privatize state enterprises, and encourage new foreign and domestic investment. In 1993, the IMF suspended Sudan's voting rights and the World Bank suspended Sudan's right to make withdrawals under effective and fully disbursed loans and credits. Lome Funds and EU agricultural credits, totaling more than one billion euros, also were suspended. Sectors Agriculture Primary resources are agricultural, including cotton, peanuts, gum arabic, and sesame seeds. Although the country is trying to diversify its cash crops, cotton and peanuts remain its major agricultural exports. Grain sorghum (dura) is the principal food crop, and wheat is grown for domestic consumption. Sesame seeds and peanuts are cultivated for domestic consumption and increasingly for export. Three main agricultural sub-sectors are active in Sudan: pastoral livestock, cropping and fish production. Livestock production has vast potential, and many animals, particularly cows, sheep, and camels, are exported to Saudi Arabia and other Arab countries. However, Sudan remains a net importer of food. Problems of investment finance, production and transportation remain the greatest constraints to a more dynamic agricultural economy. A major problem which has been growing for decades is the continual loss of open lands previously used for animal grazing to mechanized drylands and irrigated farming. Sudan has 84 million hectares of arable land and less than 20% is cultivated. Major agricultural projects such as the Gezera Scheme in Gezira state are underway in order to make Sudan food self-sufficient. Sudan is one of the world's potential breadbaskets and Sudan is nicknamed as the Arab world food basket as it accounts for 45% of arable land in the Arab world. In 1998 there was an estimated 16.9 million hectares (41.8 million acres) of arable land and approximately 1.9 million hectares (4.7 million