Both young and fully grown plants collapse in a very short time (starting from the bottom) as if they do not get water. Indeed they do not get water, because the vascular system is blocked by the fungus. The disease spreads from one plant to another , sometimes trough flood and open channel irrigation.
Wilt might also be a result of collar rot.
vascular system blocked. fusarium infected spot
Creating proper growing conditions is the best way to overcome Fusarium wilt. Make sure the soil is draining well, avoid the creation of a hard pan when planted by machine, install drainage if needed, plant on ridges. Do not over water. Do not combine Jatropha with plants from the solanaceae family, because they are hosts.
Once Fusarium nests in your soil, it is very difficult to fight. Soil fumigation or drenching with Benlate 50gr/100 ltr is a very expensive and drastic solution.
Good results have been reported with Trichoderma fungus 250 gr/ha at planting
BAVISTIN?, 0.2% COC, Bordeaux drenching
NOTE: THE USE OF ANY RECOMMENDED TREATMENT ON THIS PAGE IS ON USERS OWN RISK AND SHOULD BE ALLOWED FOLLOWING LOCAL LAW AND REGISTRATION. (Actually this is a big problem, since no pest- or fungicides are being specifically registered for Jatropha. Jatropha as a crop is simply too new and only recently got the interest from pesticide manufacturers)