Climatic and soil conditions permit the cultivation of a wide range of crops, not only tropical varieties but also many originating in semitropical and temperate zones. Until the late 1950s, however, the major emphasis in agriculture was on rice and, secondarily, on rubber, which together accounted for over half the value of all commodity exports. Other crops regularly grown included maize, cassava, potatoes, yams, beans, sugarcane, fruit, cotton, and various oilseeds, but all were supplementary and intended basically for domestic use. Historically, Thailand’s independent status had kept it from being saddled with a colonial plantation economy, in which two or three principal crops were produced for world markets or for the imperial power. Agricultural production, however, had been strongly influenced by the West after the Bowring Treaty of 1855 with Britain, which resulted in crop diversification (see The Bangkok Period, 1767-1932 , ch. 1). Accordingly, when new market conditions-- increased world demand, higher prices, and developing domestic industry--arose during the 1960s and 1970s, Thailand’s independent small farmers responded by expanding substantially the output of many secondary crops. The flexibility of the Thai farmer was evidenced by an unprecedented shift from rice production to other crops by a considerable number of households. In other cases, many farmers continued to produce rice for subsistence purposes while expanding their activities to grow market-oriented upland crops. In the mid-1980s, major export crops included not only rice and rubber but also maize, cassava, sugarcane, mung beans, tobacco, and sorghum. Other important crops in which major production increases also had been made were pineapples, peanuts, cashew nuts, soybeans, bananas, sesame, coconuts, cotton, kapok, and castor beans.