Cacao sustainability: The case of cacao swollen-shoot virus co-infection

PLoS One. 2024 Mar 7;19(3):e0294579. doi: 10.1371/journal.pone.0294579. eCollection 2024.

Abstract

The cacao swollen shoot virus disease (CSSVD) is among the most economically damaging diseases of cacao trees and accounts for almost 15-50% of harvest losses in Ghana. This virus is transmitted by several species of mealybugs (Pseudococcidae, Homoptera) when they feed on cacao plants. One of the mitigation strategies for CSSVD investigated at the Cocoa Research Institute of Ghana (CRIG) is the use of mild-strain cross-protection of cacao trees against the effects of severe strains. In this study, simple deterministic, delay, and stochastic ordinary differential equation-based models to describe the dynamic of the disease and spread of the virus are suggested. Model parameters are estimated using detailed empirical data from CRIG. The modeling outcomes demonstrate a remarkable resemblance between real and simulated dynamics. We have found that models with delay approximate the data better and this agrees with the knowledge that CSSVD epidemics develop slowly. Also, since there are large variations in the data, stochastic models lead to better results. We show that these models can be used to gain useful informative insights about the nature of disease spread.

MeSH terms

  • Badnavirus*
  • Cacao*
  • Coinfection*
  • Viruses*

Supplementary concepts

  • Cacao swollen shoot virus

Grants and funding

This project is supported by AIM’s SQuaREs research program on ‘Sustainable plant harvest in fragmented landscapes’. FBA was partially supported by the University of Kansas General Research Fund allocation 2301-2105090 and National Science Foundation grant EPSCoR OIA-1656006. MCAL acknowledges support from Basque Center for Applied Mathematics (BCAM) Research Visit Fellowship. NH appreciate PVAMU sabbatical. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.