Biomass yield between 56 accessions of leucaena were observed at Suwanvajokkasikit Field Crops Research Station Nakhonratchasima province. Randomized block design was used with 3 replications and 56 accessions as treatments. Leucaena was harvested at 2 years of age. Plant length wood yield branch yield and leaf yield were collected. Averaged plant length was in range of 6.84-11.87 meters with KU19 was highest in length. Five accessions that produced more wood yield were KU15 KU38 KU1 KU19 and KU10. Yield of these accessions were 24.07 21.96 16.71 15.36 and 14.95 t/rai with ash content at 1.43 1.04 1.76 3.66 and 1.34 percent respectively while native leucaena (KU20) had the lowest yield (0.91 t/rai). Branch yield among the accessions; KU1 KU10 KU38 KU 15 and KU19 had the greatest branch yield averaged 3.04 2.76 1.62 1.42 and 1.38 t/rai respectively. While top five in leaf yields were in KU15 KU56 KU45 KU39 and KU19 at 1.12 1.11 0.88 0.87 and 0.86 t/rai respectively.

Energy is an important factor in the necessity of human life. Many countries around the world are seeking alternative energy sources. To use as alternative energy. Our alternative sources of energy are ethanol which can be produced from agricultural products. Including plants with cellulose components. The ethanol can be mixed with gasoline. It is a new product called gasohol. This research use of fresh water weed Hydrilla is a raw material in the production of ethanol. Hydrolysis sweetening and fermentation. The microorganisms used in fermentation processes the yeast is found Hydrilla through hydrolysis the acid is H2SO4 at 0.5 % . Measuring the concentration of the alcohol concentration of 4.0 % VOL 9 Brix %. The Hydrilla through hydrolysis at alkaline NaOH is at a concentration of 1 % concentration of alcohol concentration was 3.5% VOL 8 Brix %. Hydrilla and the Hydro Delight with distilled water (H2O) to measure the concentration of the alcohol concentration of 5.5 % VOL 12 Brix %. Thus it can be said that Hydrilla is a material that has the potential to produce ethanol for energy alternatives. And used as a source of renewable energy. Instead of using raw materials from food plants. And other energy crops.