In this study, all the components of Jatropha circus and Morus indica were chemically characterized and their biochemical methane potentials (BMP) were determined. From the variables that showed strong influence on the ultimate methane yield (B(o)) of J. curcus, a multiple regression Jatropha model was developed. This model comprised of total carbohydrates, protein, lipid, acid-detergent fiber (ADF), cellulose and ash in ADF as independent variables, with r(2) value of 0.943. The Jatropha model was validated on 7 samples of M. indica parts and wastes from silkworm rearing trays of this study and 13 samples of heterogeneous organic wastes of earlier studies, to judge the prediction quality. It was found that most of the predicted values differed by less than 15% of their experimental B(o). (C) 2009 Elsevier Ltd. All rights reserved.