Does iJatropha curcas/i L. show resistance to drought in the Sahelian zone of West Africa? A case study from Burkina Faso

摘要

Land degradation is an environmental problem which weakensagro-sylvo-pastoral productivity in sub-Saharan Africa. The most commonmanifestation of land degradation is the appearance of denuded land. Wecarried out an experiment to test the effect of three soil and waterconservation techniques on survival and growth of Jatropha curcas seedlings transplantedonto two completely denuded lands in the Sahelian and Sudanian zones ofBurkina Faso. We implemented an experimental design with three replicatesper restoration technique. A total of 174 seedlings were planted in eachstudy site. The results showed that the soil water content varied accordingto the restoration technique used (df = 2; F = 53.21; p < 0.00) as wellas according to study site (df = 1; F = 74.48; p < 0.00). Soil watercontent was significantly lower in the Sahel than in the Sudanian zone.Seedling survival rate varied significantly according to technique used(df = 2; F = 8.91; p = 0.000) and study site (df = 1; F = 9.74; p = 0.003). Survivalrate, diameter and seedling height were highest at the Sudanian site. At theSahelian site, all seedlings died 2 years after establishment. Theseresults suggest that J. curcas is unsuited to denuded land in the Sahelian zone. Mostof the plants died in the Sahel between April and May, which is the peak ofthe dry season; this may be an indication that J. curcas may not be asdrought-resistant as suggested by the prolific literature which has reportedon diverse claims surrounding this plant.