Germination of Jatropha curcas in response to dessication and storage temperature

Jatropha is an emerging crop which is being promoted as an alternative feedstock for biofuels. It belongs to the family Euphorbiaceae and the genus Jatropha has approximately 175 succulents, shrubs and trees. The crop has been described as a wonder crop as the seeds contain around 37% oil which can be combusted as fuel without refining. It is claimed that Jatropha can be grown on marginal land and therefore it will not compete with crop-land unlike other edible oil such as oil palm. The above-mentioned positive characteristics have resulted in new areas for growing Jatropha and thus the need for planting materials. Jatropha can be grown both via cutting as well as seeds, however, seeds are preferred as it is easy to handle and transport. A number of reports have shown that Jatropha seeds deteriorate rapidly in storage and therefore cannot be stored for prolonged period of time. This study was initiated in order to determine the effect of desiccation on germination and storage of jatropha seeds under three conditions namely in the deep freezer, in the fridge and under room temperature. The local Malaysian variety was used in this study. Mature seeds were desiccated to 35, 25, 15, 10 or 7% and subjected to germination test. Seeds from each of this treatment was also extracted and placed in storage under the three conditions mentioned earlier for one, two or three months. The results of this study indicated that Jatropha seeds tolerated desiccation to low moisture content of below 10% and are not sensitive to temperature below freezing. This indicates that Jatropha seeds can be classified as orthodox. However, if seed moisture content is more than 10%, they undergo freezing injury if kept under freezing conditions. No significant decline in germination was observed for seeds with moisture content below 10% irrespective of condition or time of storage. Further studies have to be carried out in order to understand the long-term storage of Jatropha curcas.