Utilization of “Uwi” Plant Resources (Dioscorea sp.) for Renewable Bioenergy

Many countries are currently making efforts to obtain alternative energy to reduce dependence on fossil energy resources. "Uwi" plant has high carbohydrate for food or support energy diversification, cause of increased productivity and tolerant of being planted on the upland. This research aims to study the potential of various types of "uwi" (Dioscorea sp.) as a raw material for ethanol products. The eight types of "uwi" were studied to see their ethanol content. There are three types of Dioscorea alata (white yam, purple yam, yellow yam), two types of Dioscorea esculenta ("gembili and gembolo"), Dioscorea bulbifera ("uwi Gandul"), Dioscorea pentaphylla ("uwi Katak"), and Dioscorea hispida ("gadung"). A field experiment with Randomized Block Design used to obtain homogenous tuber raws material, followed by laboratory test of ethanol content. The research showed that the kind of Dioscorea hispida had the highest ethanol content (4.94%), followed by Dioscorea esculenta (4.16%) and white yam (3.89%). The lowest levels obtained by Dioscorea pentaphylla (0.36%) and Dioscorea bulbifera (1.53%). However, in terms of productivity, Dioscorea alata (white-yam) is the most prospective considering its high production, ease of cultivation technique and tolerance of forest stands.