Domestication of Jatropha Curcas for Oil Production on Smallholder Farms in the Sudano-Sahelian Region with focus on Mali, 2009-2013

Project summary

This project shall contribute to sustainable, local production of bio-diesel from Jatropha curcas in Mali by establishment and dissemination of basic pre-breeding knowledge and facilitate future access to tested and selected plant material. The project is based on the idea that deployment of genetically improved and tested plant material can enhance production and reduce risk for the farmers. Jatropha curcas is a tropical shrub native to tropical America, but grown throughout the tropics. The species is suitable for dry sites and seeds contain up to 38% oil. It is easy to grow and widely used for e.g. erosion control, fencing around arable land, firewood, manure, various medicinal uses, fodder, and soap production. Cultivation of J. curcas for bio-energy has multiple development potentials: employment, income, local added value, import independency on energy, carbon sequestration, and as substitute for fossil energy. However, verified data on oil yield under different growing conditions is very limited. Also, guidance regarding sustainable domestication and access to planting material tested under different growth conditions are lacking. Cultivation of J. curcas may therefore involve un-needed risk for the growers, and the potential of utilising selected planting material remains un-utilised. No systemic exploration of the genetic resources of J. curcas has been made in any African country. The present project will therefore study productivity of J. curcas across environments, estimate genetic parameters and genetic reaction norms across climatic gradients within Mali, and develop basic pre-breeding knowledge including understanding of breeding systems and characterisation of the gene resource available for farmer-based domestication in Mali. Innovative approaches for farmer lead domestication of J. curcas shall be developed including adaptive strategies towards climate change. Finally, the project shall identify alternative oil producing species for arid and semi-arid lands as input to a diversification strategy. The project is based on cooperation between partners in Denmark and Africa, and will benefit from both DNA studies, field testing, surveys and joint development of thoughts and ideas. Capacity building and knowledge sharing are important aspects in all parts of the project.

Outputs

Completion Report - Summary:

The overall objective of this project was to test and improve the options for production of local, renewable biomass based energy based on planting on Jatropha curcas.

Molecular studies showed low levels of genetic variation, but field trials revealed flushing time, growth, seed production and oil content of seeds depended on the seed source. Even variation according to the individual mother tree could be observed in growth and seed production.

The findings supports that choice of appropriate seed sources is important if deciding on planting J. curcas and room for some improvement through breeding seems present. However, during the first years of growth covered by this project, only trees at one of the trial sites yielded moderate fruit production, while only sporadic fruit set was observed on trees at three trial sites and very low or no fruit yield was recorded on trees in the remaining three trial trials, whereof two were lost already in 2011. Survival was lower than 20% in two of the field trials. Correlation in survival between landraces and provenances across the
sites was small.

Production of fruits may increase once trees grow older, but based on the present findings the possibility of obtaining high yielding J curcas varieties for local production of renewable biomass sources on dry sites seems limited.