Experimental cocoa cultivations systems in Cameroon: agronomical and economical performances assessment

On farm trial plots were set up in Cameroon, according to three intercropping designs: cocoa-fruit trees (970 cocoa trees and 160 fruit trees/ha), cocoa-oil palm trees (700 cocoa trees/ha and 120 oil palm trees / ha) and cocoa-coconut trees (810 cocoa trees / ha and 143 coconut trees/ha). Cocoa yield was recorded on 48 of these cocoa trial plots set up in five locations in Cameroon in 2006, 2007 and 2008, and showed a large range of variation (between 200 and 1,450 kg/ha/year) among plots, with an average value of 600 kg/ha/year, close to the yield usually observed on traditional cocoa plots in the central region of Cameroon. Despite their initial higher cocoa tree density, the plots where cocoa is intercropped with fruits trees show a slightly lower yield than the ones intercropped with oil palm or coconut trees. The yield of fruit trees was recorded on two sites (five plots per site) and was found to vary largely between these two sites. The gross revenue from fruits was estimated from information provided by four farmers in the site where fruit yield was higher, and was found to range between 300 and 800 US $/ha/year. In the case of two of the four plots, the cumulated annual gross revenue from cocoa and fruits was found higher than the one expected if the plot had been set up only with cocoa trees, at the cocoa density generally observed in the cocoa plots in this site (1,100 trees/ha). On the other hand, it appears that cocoa cultivation alone would have brought more revenues in the case of the two other plots. The gross annual revenue from oil palm trees, calculated from the information reported by four farmers, was found to range between 300 and 2,300 US$/ha. Two comparisons were made between annual cumulated gross revenues from cocoa and palm oil and 1) estimated revenue from cocoa if the plot was set up only with cocoa trees, at a 1,100 cocoa trees/ha 2) estimated revenue from palm oil if the plot was set up only with oil palm trees, at the recommended density of 169 trees/ha. 1)In the case of two of the four plots, intercropping failed to enhance the revenues from the plot. On the other hand, oil palm trees appeared to dramatically enhance the revenues from one of the other plot, while cocoa alone would have brought more revenue to the last plot. 2) In the case of three of the plots, intercropping cocoa with oil palm generated more revenue than oil palm only at the 169 oil palm trees/ha recommended density, the revenues being equivalent in the forth plot. The three farmers who sat up plots with intercropping cocoa with coconut trees in 2006 and 2007 whether failed to establish the coconut trees or, disappointed by the agronomical and economical of these trees, partially replaced them with oil palm trees. The consequences of these results for intercropping are discussed in the paper. (Resume d'auteur)