Spatial variability of shade and its effects on cocoa trees productivity in agroforestry systems

Abstract

The impact of intra-plot multi shading on cocoa tree productivity is a widely exploited aspect of agroforestry practice. This study, conducted on 1,000 m2 experimental plots at three agroclimatic sites in Cote dIvoire (Azaguie, Divo, Soubre), mapped the spatial heterogeneity of shade provision using light intensity measurements and then calculated cocoa productivity over two years of data collection. A geostatic approach (ordinary kriging) was used to analyze the shade in agroforestry plots, which revealed significant heterogeneity. This heterogeneity was primarily attributed to the phenological diversity of the companion trees. The analysis revealed that low shading levels (approximately 30%) emerged as thresholds where cocoa productivity was highest. However, it was observed that elevated shading levels, exceeding 60%, resulted in a significant decline in productivity. Among the companion trees, Ceiba pentandra, Eleais guineensis, and Persea americana offer light to moderate shade. Conversely, certain trees that provide heavy shade, such as Mangifera indica, are identified as less beneficial because they significantly reduce cocoa productivity.