Characterization of Swollen Shoot Disease and Evaluation of the Effectiveness of Rehabilitation Technology in Cocoa Farms in Gbazoa, Amaragui and Liliyo, Côte d'Ivoire

Abstract

Objectives: The study carried out on swollen shoot disease in the Nawa region in Côte d’Ivoire aimed to monitor the early progression of this disease in cocoa (Theobroma cacao L.) plantations rehabilitated using three innovative technologies. The goal was to reduce the damage caused by swollen shoot disease in cocoa production systems. Methodology and Results: Quarterly data collection in each plot, using Global Positioning System (GPS) and visual observations, were made to determine the prevalence, incidence, and severity of the cocoa swollen shoot disease within the rehabilitated plots. The rehabilitated plots were found in close proximity to plots already affected by the disease, and virus host plants were identified within the rehabilitated cocoa plots. Newly infected cocoa trees were found in the immediate vicinity of the disease foci. The number of newly infected cocoa trees was found to be proportional to the size of the disease focus. The highest prevalence and severity of the disease were recorded in Grafted trees on Old Cocoa farms (GOC), with 1.28 % and 1.55 %, respectively. The highest incidence of 1.26 % was observed among Replanting with Grafted Cocoa trees (RGC). Conclusion and Application of Results: This study revealed the presence of the cocoa swollen shoot disease in the plots through its characteristic symptoms. The progression and severity of the symptoms were found to depend on the technology used. The presence of virus infected plants within and around the plots indicates either a lack of strict adherence to disease control methods or insufficient knowledge about these host plants during the establishment of the plots. These results will enable producers to better manage the disease, starting with the identification of cocoa swollen shoot virus (CSSV) host plants and the precautions to be taken when using maintenance and grafting tools between infected and non-infected cocoa trees. The implementation of early virus detection tools accessible to producers would be an asset in the fight control of the swollen shoot disease in cocoa.