1. International Centre for Advanced Mediterranean Agronomic Studies (CIHEAM-Bari), Via Ceglie 9, Valenzano, 70010 Bari, Italy
2. Department of Geography, Faculty of Letters and Human Sciences, Abdou Moumouni University, Niamey P.O. Box 237, Niger
3. Programme Agrinovia, Joseph Ki-Zerbo University, 03 BP, Ouagadougou 7021, Burkina Faso
4. University Centre of Gaoua, Nazi BONI University, 01 BP, Bobo-Dioulasso 1091, Burkina Faso
5. Department of Rural Engineering, Water and Forests, Faculty of Agronomy, Abdou Moumouni University, Niamey P.O. Box 237, Niger
6. Biosciences Laboratory, Joseph Ki-Zerbo University, 03 BP, Ouagadougou 7021, Burkina Faso