Abstract
Jatropha (Jatropha curcas L.) is one of the important oil crops as a source of bio-diesel fuel. Attempts were made to analyze the morphological features of Jatropha seeds and the effect of temperature on the germination percentage and rate. Seed shape was oval, and the long diameter, width and thickness were 18.5 ± 0.8 mm, 11.4 ± 0.5 mm and 8.7 ± 0.5mm, respectively (mean ± S.D.). After removal of the seed coat, seed germination percentages were higher than those of control seeds. Effects of different physical treatments of Jatropha seed surface on the germination percentages were analyzed. Control, slash and grind treatments led to low germination percentages without significant differences among them, while partial and full removal led to higher germination percentages without significant differences between them. We measured the germination percentage and germination rate to elucidate the effect of temperature (20, 25, 30 and 35 ˚C) on them. At 30 ˚C, seeds with the removal of the outer seed coats showed high germination percentages and germination rates. It was estimated that the removal of the outer coat increased the emergence of seeds in fields, and the optimal temperature was around 30 ˚C.
