Rehabilitation practices in cocoa agroforestry systems mitigate outbreaks of termites and support cocoa tree development and yield

Abstract

Most smallholder cocoa farmers in West Africa are not equipped with the necessary tools, techniques, and practices to rejuvenate their aging cocoa farms. Instead, they rather prefer to establish new cocoa farms at the expense of forest remnants. Poor management of their overaged farms has resulted in the emergence and outbreaks of new pest species such as termites feeding on the remaining productive trees and negatively affecting overall yield. We investigated how rehabilitation pruning of cocoa trees influences termite outbreaks and yield in three cocoa agroforestry systems (rustic, intermediate and full sun systems). We monitored cocoa and non-cocoa trees at different development stages after rehabilitation pruning and assessed termite diversity and damage. We demonstrated that farm rehabilitation practices are associated with high beta diversity of shade trees and linked with a high diversity of beneficial termite species. Cocoa trees and farm age were positively correlated with the level of infestation by termite species. We also showed that rehabilitation practices improve cocoa tree vigor and yield in cocoa agroforestry systems with the intermediate systems as the most productive after pruning (167 % of yield increase after pruning). Rehabilitation pruning is a suitable practice to rejuvenate aging trees and increase short-term cocoa yield while mitigating the negative effects of insect pests such as termites. It could be recommended as an effective measure for sustainable cocoa production, thereby enhancing ecosystem services provided by local biodiversity and avoiding forest clearance.