Adaptation, Biomass and Ethanol Yields of Sweet Sorghum (Sorghum bicolor (L.) Moench) Varieties at Dryland Farming Areas of Jimbaran Bali, Indonesia

Decreasing the availability of fossil energy sources in Indonesia, demand that an alternative and renewable source of energy is to be found. Sweet sorghum is a possible candidate for a cheap and renewable source of energy. An experiment was conducted to study the adaptation of sweet sorghum varieties and to find out the optimum rate of organic manure for high biomass and ethanol yields in dryland areas at Jimbaran, Badung, Bali. The experiment was a two factor experiment in a randomized complete block design with three replications. The first factor was four sorghum varieties, three varieties originated from Japan viz. Kotobun sorgo (FS501), Big sugar sorgo (FS902), Super sugar (KCS105) and Local Belu originated from East Lesser Sunda islands, Indonesia, and the second factor was four rates of organic manure of 0, 10, 20, 30 t ha-1. The four varieties adapted well on dryland areas at Jimbaran, Badung, Bali, butFS902, KCS105 and Lokal Belu had better growth compared to FS501. The variety of KCS105 resulted in significantly (P<0.05) highest total biomass fresh and dry weight of 28.2 and 9.7 t ha-1 , respectively, stem sugar yield of 2.6 t ha-1and stem ethanol yield of 6493.3 l ha-1, which was 63.3% higher than that of Local Belu eventhough their ethanol content were similar. No significant effect was found in the rates of organic manures and the interaction between the two factors on biomass, sugar and ethanol yields. The optimum rate of manure for highest biomass, sugar and ethanol yields was not found in this experiment. It was concluded that the four sorghum varieties were well adapted and KC105 produced highest biomass and ethanol in dryland areas at Jimbaran, Badung, Bali. Keywords: Adaptation, Biomass, Ethanol, Sweet sorghum (Sorghum bicolor (L.) Moench).