|Riassunto in Inglese:|
Jatropha curcas L. is an oleaginous crop belonging to the Euphorbiaceae family, native to Central America and part of South America, that in the last decade has obtained more and more attention, as feedstock for biofuel production. However, the harvesting of this plant presents several problems, because fruits are in bunches and do not ripen simultaneously. In fact, the identification of mechanical solutions that allow to facilitate harvesting are still limited. Some mechanical and semi-mechanical harvesting methods have been developed worldwide with the purpose to optimize the harvesting process, reducing harvesting costs, and make this crop competitive with the other energy crops. This research leads to the identification of the existent harvesting methods, according to the level of mechanization applied: manual picking, semi-mechanical harvesting, and full-mechanized harvesting. The manual picking is the most common and precise harvesting method but also the most unproductive. Mechanical harvesting carried out with modified grapes or coffee harvesters resulted very productive, but very costly as initial investment. The semi-mechanical harvesting method was achieved with shaker tools employed to facilitate the fruit detachment. This system resulted much cheaper than the fully mechanized one and quite flexible for small and medium scale applications, but it still requires adjustments for improving the productive performance. The harvesting of Jatropha curcas L. remains a big constrains for the spread of the species as energy crop, and this work aims at presenting an overview of the harvesting methods for jatropha, showing the pros and cons of each system, and highlighting the criteria to be considered for choosing one respect another. The second focus of this paper is the logistic of the jatropha harvesting, which has been described and schematized for each harvesting method identified.