The authors thank DSM Nutritional Products for partial financial support. W. Kaewlamun was supported by the Royal
Golden Jubilee PhD Program of the Thailand Research Fund and PHC Franco-Thai project year 2007–2008. M. Okouyi was supported
by the Gabonese government. Dominique Tristant and the farm workers at the experimental farm of AgroParisTech,
Thiverval-Grignon and the technical assistance of Christine Ficheux and Ophélie Dhumez are also acknowledged.