QUOTE FROM WIKIPEDIA
It has recently been shown in Kenya that Croton nuts, such as those from C. megalocarpus, are a more economical source of biofuel than Jatropha. In Kenya, Jatropha requires as much as 20,000 litres of water to make a litre of biofuel, while Croton trees grow wild and yield about 0.35 litres of oil per kilo of nuts. Croton trees are planted as a windbreak in Kenya and its use as a source of biofuel may benefit rural economies there. As arable land is under population pressure, people have been cutting down the windbreaks to expand farmland. This new use may save the windbreaks which should help fight desertification.
NOTE FROM THE AUTHOR
The statement above is a typical quote from somebody who knows nothing about agronomy and utterly nonsense. Jatropha yields about 0.25 ltr of oil per kg of nuts. Croton yields about 0.35 kg of oil per kg of nuts. So far so good. Jatropha is a shrub that sheds its leaves in dry season and starts to produce fruits after 1 year. Croton is almost evergreen and starts to produce fruits after 3 years. The fact that croton is a tree and evergreen implicates that it uses much more water than the Jatropha. A Jatropha that sheds its leaves hardly evaporates water.The only reason that Croton can become more profitable than Jatropha is the fact that it becomes a big tree so it absorbs more CO2, which is an asset. But it has nothing to do with water consumption.