Coffee leaf rust

Context

• Coffee: important cash crop for many countries in the tropics
• Coffee leaf rust (basidiomycete fungus Hemileia vastatrix) is the most serious leaf disease (premature defoliation, flower & fruit abortion, shoot desiccation), inducing major crop losses
• Control methods: fungicides vs quarantine, cropping practices, resistant cultivars, biological control (still under development)
• Existing model(s) simple dynamic model [Vandermeer et al. 2014] and transmission rate estimations based on field experiments [Vandermeer et al. 2018]; interaction model between rust and a bacterial biological control agent, with stochastic spore dispersion in a discrete space [Arroyo Esquivel et al. 2018]

J. Vandermeer, P. Rohani. The interaction of regional and local in the dynamics of the coffee rust disease, 2014. arXiv:1407.8247

J. Vandermeer J, Z. Hajian-Forooshani, I. Perfecto. The dynamics of the coffee rust disease: an epidemiological approach using network theory. European Journal of Plant Pathology 150: 1001, 2018. DOI: 10.1007/s10658-017-1339-x

J. Arroyo-Esquivel, F. Sanchez, L.A. Barboza. Infection model for analyzing biological control of coffee rust using bacterial anti-fungal compounds. Mathematical Biosciences 307: 13-24, 2019. DOI: 10.1016/j.mbs.2018.10.009

Objectives

• To develop a model representing coffee leaf rust damages in a coffee plot
• To design efficient and sustainable control strategies

Work progress

Achieved

• Spatio-temporal PDE model of coffee rust spread: model analysis (equilibria, stability, basic reproduction number and numerical simulations
• Refined non-spatial ODE model describing the fungus propagation on juvenile and mature berry-producing branches

Clotilde Djuikem. Modelling, Analysis and Simulation of fungus Hemilia vastarix, coffee pest. Master thesis in Mathematics and Applications, University of Douala, April 2018. Supervisors: S. Bowong and R. Tagne.

C. Djuikem, F. Grognard, S. Touzeau, S. Bowong. Modelling and controlling fungus Hemileia vastatrix, a coffee pest. Talk in: BIOMATH 2019 – International Conference on Mathematical Methods and Models in Biosciences, Bȩdlewo, Poland, 16-22 June 2019. HAL Id: hal-02309454

C. Djuikem, F. Grognard, R. Tagne, S. Touzeau, S. Bowong. Modelling coffee leaf rust dynamics to control its spread. Mathematical Modelling of Natural Phenomena 16: 26. DOI: 10.1051/mmnp/2021018. HAL Id: hal-03188365

Ongoing / future work

• Implementation of sustainable control methods, based on alternatives to fungicides (continuous or impulsive control)
• Extension to a multi-seasonal framework (hybrid model)

C. Djuikem, A. Yabo, F. Grognard, S. Touzeau. Mathematical modelling and optimal control of the seasonal coffee leaf rust propagation. Talk in: ADHS 2021 – 7th IFAC Conference on Analysis and Design of Hybrid Systems, Brussels, Belgium, 7-9 July 2021. IFAC-PapersOnLine 54(5): 193-198. DOI: 110.1016/j.ifacol.2021.08.497. HAL Id: hal-03274865

Misc

• Participation in the International Graduate School on Control, M18 Hybrid Control Design, L’Aquila, Italy, 13-17 May 2019 (overseas grant)
• Inria CORDI PhD grant, 2019-2022: Modelling and control of perennial plant phytopathogens