The main secondary crops in the late 1980s were maize, cassava, sweet potatoes, groundnuts, soybeans, sesame seeds, dry beans, and rubber (see table 10, Appendix A). According to Phnom Penh, the country produced 92,000 tons of corn (maize), as well as 100,000 tons of cassava, about 34,000 tons of sweet potatoes, and 37,000 tons of dry beans in 1986. In 1987 local officials urged residents of the different agricultural regions of the country to step up the cultivation of subsidiary food crops, particularly of starchy crops, to make up for the rice deficit caused by a severe drought.
The principal commercial crop is rubber. In the 1980s, it was an important primary commodity, second only to rice, and one of the country's few sources of foreign exchange. Rubber plantations were damaged extensively during the war (as much as 20,000 hectares was destroyed), and recovery was very slow. In 1986 rubber production totaled about 24,500 tons (from an area of 36,000 hectares, mostly in Kampong Cham Province), far below the 1969 prewar output of 50,000 tons (produced from an area of 50,000 hectares).
The government began exporting rubber and rubber products in 1985. A major customer was the Soviet Union, which imported slightly more than 10,000 tons of Cambodian natural rubber annually in 1985 and in 1986. In the late 1980s, Vietnam helped Cambodia restore rubber-processing plants. The First Plan made rubber the second economic priority, with production targeted at 50,000 tons-- from an expanded cultivated area of 50,000 hectares--by 1990.
Other commercial crops included sugarcane, cotton, and tobacco. Among these secondary crops, the First Plan emphasized the production of jute, which was to reach the target of 15,000 tons in 1990 (see table 11, Appendix A).
Data as of December 1987