PhD
- University of Dschang, Cameroon, Jan. 2017-Jan. 2022
- Title: Modelling, analysis and control of coffee berry borer
- HAL: tel-03608463
- Supervisors: B. Tsanou, S. Touzeau, F. Grognard, S. Bowong
- Partner: IRAD
Context
- Coffee: cash crop for tropical developing countries – 25 million households [FAO]
- Coffee berry borers (CBB) Hypothenemus hampei
- mostly develop and feed in coffee berries
- severe damages (berry quality and yield) and economic losses
- Control methods
- insecticides: limited effectiveness
- cropping practices: removing dropped berries, strip-picking, stump pruning
- traps
- biocontrol agents: parasitoid or predator insects, entomopathogenic fungi
Objectives
- Develop a model representing coffee berry borer damages in a plantation
- Design efficient control strategies, based on alternative methods to pesticides
Results
Modelling coffee berry borer dynamics
- Single-season model, based on the insect life-cycle and including the berry availability during a cropping season
- ODE model with free colonising females and within-berry infesting females
- PDE with berry maturation age structure, to introduce CBB preference for mature berries
Yves Fotso Fotso, Suzanne Touzeau, Berge Tsanou, Frédéric Grognard, Samuel Bowong. Mathematical modelling of a pest in an age-structured crop model: The coffee berry borer case. Applied Mathematical Modelling 110:193-206, 2022. DOI: 10.1016/j.apm.2022.05.042. HAL: hal-03505679
- Multi-seasonal model to represent several cropping seasons and harvests (hybrid model)
F. Grognard, S. Bowong, Y. Fotso Fotso, S. Touzeau, B. Tsanou. A multi-seasonal model of plant-pest interactions: the coffee berry borer. In: MPDEE 2022 – Conference on Mathematical Population Dynamics, Ecology and Evolution, Stellenbosch, South Africa, 13-17 June 2022. HAL: hal-03694889
Optimal control to maximise profit
- Control(s): biological control, such as entomopathogenic fungus Beauveria bassiana & traps
- Aim: maximise the yield at the end of the cropping season, while minimising the control costs and the borer population for the next cropping season
- Bounded control, no persistence
Y. Fotso Fotso, F. Grognard, B. Tsanou, S. Touzeau. Modelling and control of coffee berry borer infestation. In: CARI’2018 – 14th African Conference on Research in Computer Science and Applied Mathematics, Stellenbosch, South Africa, 2018. HAL: hal-01871508
- Control persistence: bio-insecticide impact lasts over time
Y. Fotso Fotso, S. Touzeau, B. Tsanou, S. Bowong, F. Grognard. Modelling and optimal strategy to control coffee berry borer infestation. Mathematical Methods in the Applied Sciences 44(18):14569-14592, 2021. DOI: 10.1002/mma.7726. HAL: hal-03334090
- Two controls: bio-insecticide and traps
Y. Fotso Fotso, B. Tsanou, S. Bowong, S. Touzeau, F. Grognard. Optimal control of coffee berry borers: synergy between bio-insecticide and traps. Journal of Optimization Theory and Applications, 196(3):882-899, 2023. DOI: 10.1007/s10957-022-02151-7. HAL: hal-03954863
- Impulsive control: bio-insecticide applied at discrete times
Y. Fotso Fotso, S. Touzeau, B. Tsanou, F. Grognard, S. Bowong. Optimal impulsive control of coffee berry borers in a berry age-structured epidemiological model. Revue Africaine de Recherche en Informatique et Mathématiques Appliquées 38(Numéro spécial CARI 2022-2023), 2024. DOI : 10.46298/arima.11338. HAL: hal-04100767
Misc
- EPITAG visits in France
- Sep.-Dec. 2017
- April-Aug. 2018
- March-July 2019
- Feb.-July 2020 (AUF grant)
- Conferences
- ECMTB 2018, Lisbon, Portugal – HAL: hal-01859994
- CARI’2018, Stellenbosch, South Africa – HAL: hal-01871508
- BIOMATH 2019, Bedlewo, Poland – HAL: hal-02309445
- CMPD5 2019, Fort Lauderdale, USA. HAL: hal-02139546
- MPDEE 2022, Torino, Italy. HAL: hal-03694889
- CARI’2022, Tunis, Tunisia & Yaoundé/Dschang, Cameroon – HAL: hal-03713440
- Research schools
- École de Contrôle Optimal Numérique, Toulouse, September 2018 (grant)
- International Graduate School on Control, M18 Hybrid Control Design, L’Aquila, Italy, May 2019 (overseas grant)
- AUF, Collège doctoral régional de l’Afrique Centrale et des Grands Lacs « Mathématiques, Informatique, Biosciences et Géosciences de l’Environnement » (MathInBio) fellowship, 2018 call
- Career after PhD
- Lecturer, University of Dschang, Cameroon, since 2022
- Postdoc, IGEPP, INRAE Rennes, France, 2023-2025 (PEPR Agroecology & ICT funding)