The experiment was located at the ICRISAT Sahelian Center (ISC), 45 km
south of Niamey, Niger at 13 ° N 2 ° E. Niamey receives an average of 562
mm of rainfall (standard deviation = 134 mm), most of which falls during
June~September. Average potential evapotranspiration during the dry
months of October-May is 1820 mm [10]. At ISC, rainfall was 700 mm in
1988 and 623 mm in 1989.