Figure 1From: Determinants of yield differences in small-scale food crop farming systems in CameroonOfficially delineated agro-ecological zones showing the locations of agricultural research centres in Cameroon and administrative units of the Western Highlands agro-ecological zone. The broken lines represent isohyets of mean total annual rainfall. Source: Institute of Agricultural Research for Development (IRAD). http://www.irad-cameroon.Back to article page