Bifurcation analysis in a coffee leaf rust epidemiological model

International audienceCoffee is an important cash crop cultivated in the tropics, which sustains the livelihood ofnot less than 125 million people worldwide. However, coffee plantations are subject tovarious diseases, among which coffee leaf rust (CLR), caused by fungus Hemileia vastatrix,which infects coffee leaves and can severely reduce coffee berry production.We developed a deterministic ODE model which describes the interaction between CLRand coffee branches in a coffee plantation. It is based on the classical SEIR epidemiologicalmodel, with an extra state variable for spores released by infected branches, which in turninfect susceptible branches. Moreover, coffee branches are subdivided into young andmature branches, the latter producing coffee berries. We computed the basic reproductionnumber R0, which classically determines the stability of the disease-free equilibrium(DFE), and studied the bifurcation around R0 = 1 using Castillo-Chavez and Song’stheorem