3.2 Possibilities of cost reduction 3.2.1 Farm cost Tracing back to farm cost, to make ethanol ex-refinery price drop below Bt 16.95 in order to be competitive with gasoline, cassava roots should be available at a market price of no more than Bt 736 per tonne. As a result, production cost for cassava farming has to drop to Bt 553 a tonne, assuming that the profit for farmer is fixed at Bt 183 a tonne. If farming cost remains the same, increasing cassava crop yield is one option for reducing farm cost per tonne of cassava. As shown in Fig. 5, the breakpoint of cassava yield at which the cost per tonne of cassava could drop to Bt 553 is 6.6 tonnes/rai, i.e., nearly double current yield of 3.4 tonnes/rai. In the short term, this seems neither feasible nor practical. During the past decade (1995-2004), the national average yield of cassava in Thailand has remained the same or increased slightly, about 5.5% a year [8]. Yield stagnation has resulted from soil losses due to erosion and inappropriate fertilizer application [13]. A combination of cost reduction in crop maintenance (fertilizer/herbicide application) and yield increase would be more practical. The straight line in Fig. 6