Sorghum grown from farm saved seeds is a major crop in the drought-threatened region of Sahel. A recent small scale study made by the applicant institutions in Burkina Faso hasdocumented >25% increase in sorghum grain yield by treating farm-saved seeds with an aqueous extract from the local and common weed, Eclipta alba (Zida et al. 2008a). The plant, E. alba, is known as a medicinal herb and published results provide evidence, that the observed effect on yield is due to an effect on seed-borne fungal pathogens. The treatment of seeds by E. alba extract is an indigenous technology already used by some farmers in Burkina Faso. The present study aims at documenting and harnessing the methodology for a wider use in African agriculture and to improve the understanding of the biological and biochemical mechanism involved. The project has four R&D objectives: 1) Testing dose-response of E. alba extract in seed treatment, 2) Testing the effect of E. alba seed treatment in relation to fungal infection 3) Testing E. alba seed treatment in a geographically distant area (Eastern Africa - Tanzania) and 4) Investigating biochemically the yield-promoting and anti-fungal activity of E. alba in seed treatment. The project involves three research institutions located in Burkina Faso, Tanzania and Denmark, respectively. The Danish Institution, Institute of Plant Biology and Biotechnology, University of Copenhagen, already has established a formal collaboration with the two African partner institutions through the Danish Seed Health Centre (DSHC).
Project Completion Report:
1) We have had been able to show that the use of a simple plant extract for seed treatment of a stable crop, Sorghum, in Burkina Faso has a positive effect on yield (17% on average). This yield increase is comparable to the effect of a synthetic pesticide (25% on average). The synthetic pesticide commonly available in Burkina Faso is highly toxic to humans and seeds in Burkina Faso are sown by hands of unprotected farm workers. Our findings therefore has the potential to improve food security and at the same time avoid a health risk to farm workers handling the seeds. The plant used for the extract, Eclipta alba, is already well known as a medicinal plant, that can be safely applied to the skin of humans.
2) We have found that the effect of seed treatment for both the pesticide and the plant extract is highly dependent on local environmental factors. In some locations up to 60% yield increase can be obtained and in other locations the yield increase is close to zero.
Through the project we have been able to better identify the areas in which seed treatment strongly can be recommended. Particulalry areas with low yield and only few plants emerging from the soil should be targeted.
The project is continued with funding from EU and more information can be found at the web-page: http://alba.ku.dk/.