acres) set aside for irrigation, primarily in the north of the country along the banks of the Nile and other rivers. Cash crops (as of 1999) grown under irrigation in these areas include cotton and cottonseed, which is of primary importance to the economy with 172,000 tons and 131,000 tons produced annually respectively, sesame (220,000 tons), sugarcane (5,950,000 tons), peanuts (980,000 tons), dates (176,000 tons), citrus fruits, yams (136,000 tons), tomatoes (240,000 tons), mangoes, coffee, and tobacco. The main subsistence crops produced in Sudan are sorghum (3,045,000 tons), millet (1,499,000 tons), wheat (168,000 tons), cowpeas, beans, pulses, corn (65,000), and barley. Cotton is the principal export crop and an integral part of the country's economy and Sudan is the world's third largest producer of sesame after India and China. Industry Sudan's rapid industrial development consists of agricultural processing, electronics assembly, plastics manufacturing, furniture, tanning, sugar production, meat processing and various light industries located in any of the 10 Industrial areas in Khartoum. Due to the many countries depending on Sudan for medicines and medical services, Sudan is now concentrating on becoming a hub for the medical industry in East Africa, providing facilities and concessions for medical investments and succeeding in covering about 70% of needs and exporting to many neighboring nations. In recent years, the Giad Industrial Complex in Al Jazirah state introduced the assembly of small autos and trucks, and some heavy military equipment such as armored personnel carriers and the “Bashir” and "Zubair" main battle tanks as well as handguns, light and heavy machineguns and howitzers and, recently, drone production. Sudan is reputed to have great mineral resources, and exploration has started extensively for gold, of which is produced nearly 30 tons annually providing a great boost to the foreign exchange reserves of the nation, with the participation of many investment companies from all over the world. Quantities of asbestos, chromium, mica, kaolin and copper are now exploited commercially, especially for export to China. Petroleum Extensive petroleum exploration first began in Sudan in the mid-1970s. Significant finds were made in the Upper Nile region and commercial quantities of oil began to be exported in October 2000, reducing Sudan's outflow of foreign exchange for imported petroleum products. Today, oil is an important export industry in Sudan. Estimates suggest that oil accounts for between 70% and 90% of Sudan's total exports. The primary importers of Sudanese oil are Japan, China,