This study is based on the work of R.V. Misra, FAO consultant.
The study benefited from the contributions of K. Isherwood, J. Poulisse and T. van den Bergen (FAO).
The cover photographs were provided by J. Borgemeister (wheat) and Arnoldo Mondadori Editore S.p.A. (potatoes and maize).
The source of the background cover photograph (rice) is FAO/18663/ G. Blaak.
