Towards domestication of Jatropha curcas

91 10.4155/BFS.09.4 © 2010 Future Science Ltd Jatropha curcas L. (further referred to as Jatropha) is a rapidly emerging biofuel crop currently attracting a lot of interest and investments [1]. This stem-succulent [2] deciduous tree or shrub produces seeds rich in toxic oil (27–40% [3]). The oil can be extracted easily with techniques of different sophistication levels [4,5]. The crude Jatropha oil meets the fuel quality standards of rapeseed [6] and can be easily converted into biodiesel, meeting US and European standards [7,8]. However, although the downstream processing is well known, the species’ agronomy and, as such, the potential seed production, is still shrouded in uncertainty. Popular claims on drought tolerance, low nutrient requirement, pest and disease resistance and high yields [9] have triggered a Jatropha hype [4,10] with skyhigh expectations on simultaneous wasteland reclamation, fuel production, poverty reduction and large returns on investments [11]. However, many of these claims are yet to be supported by scientific evidence [4,12]. Major knowledge gaps concerning basic ecological and agronomic properties (growth conditions, input responsiveness of biomass production, seed yield and the species’ genetics), make seed yield poorly predictable [4,10]. Considering the current expansion [1], this situation might hold considerable sustainability risks (economic, social and environmental) [3]. Among other issues, the water requirement [2] and water footprint (amount of water needed per GJ biodiesel) [13,14] of Jatropha are still poorly understood. A better knowledge of these agronomic properties is vital for the further application of the species. Jatropha can still be considered a (semi-)wild, undomesticated plant showing considerable performance variability [4,10,11]. Biofuels (2010) 1(1), 91–107 Towards domestication of Jatropha curcas