[PhD student] Houssem Triki: Interactions between pest attacks and plant growth using a model approach applied to robusta coffee in Uganda. Effects on production

Interactions between pest attacks and plant growth using a model approach applied to robusta coffee in Uganda. Effects on production

I hold a bachelor's degree in electronics and a Master's degree in automation research from the University of Djelfa in Algeria. I then obtained a Master's degree in Systems, Autonomous Machines and Field Networks at the University of Lille.
I'm working on the creation of a formalism coupling plant growth models and disease and/or pest attack models. The target crop is robusta coffee, a shrub grown in Uganda. Also, my aim is to have a means of monitoring the effects of diseases and their repercussions on both plant growth and profitability, in order to help Ugandan growers. In this way, I hope to provide a basis for building digital decision-support tools to support sustainable production locally. I've always been fascinated by life sciences and environmental issues. These themes are at the forefront of my thesis, as is internationality, since my work is part of the European DeSIRA "ROBUST" project, which aims to support sustainable economic development in Uganda by promoting and improving agroforestry Robusta coffee cropping systems.

• Starting date : 3rd January 2022
• University : Université de Montpellier
• PhD school : Information Structures Systèmes (I2S)
• Scientific field : IT and environment sciences
• Thesis management : Marc Jaeger (Amap, Cirad)
• Thesis management : Fabienne Ribeyre(PHIM, Cirad) , Fabrice Pinard(PHIM, Cirad)
• Funding: Projet Européen DeSIRA / CIRAD
• #DigitAg : Labeled thesis – Axe 6 : Modélisation et simulation (systèmes de production agricole), Axe 2 : Innovations en agriculture numérique Axe 3 : Capteurs, acquisition et gestion de données, Challenge 1 : Le challenge agroécologique Challenge 3 : La protection des cultures Challenge 5 : Les services de conseil agricole

Keywords: Dynamic systems, FSPM, Coupling, Bioagressors, GreenLab, Coffee, Rust, BTB, Scolyte, Uganda

Abstract: One of the difficulties facing coffee producers is the attack of pests. In Uganda, coffee production is heavily affected by fungi (rust, tracheomycosis) and pests (BTB, bark beetle). For example, the outbreak of tracheomycosis greatly reduced the production and number of coffee trees in Uganda in the 1990s and 2000s, resulting in heavy economic losses. About 20% of the population depends on coffee production for their livelihoods, and pest control is expensive. In this context, it is important to know how to assess the yield losses that a pest will cause in order to decide whether or not to treat it. This thesis is a contribution to answer this question. The objective of this thesis is to develop a method for coupling attack models of different pests with a plant growth model. The practical aim is to establish the basis of a tool for predicting the short- and long-term impacts of rust and BTB on coffee production. The construction of this coupled model will make it possible to integrate the interactions between the pest and the plant. These are important to understand their respective evolutions. A pest has direct and indirect effects on organs (e.g. on fruit production) and also repercussions on the subsequent phenology and growth of the plant (feedback), which are spread out over time. Conversely, the dynamics of the pest over time may depend on the growth and phenology of the plant. The integration of these feedbacks, which are often neglected, into the models will make it possible to predict the long-term evolution of production in relation to the climate and the presence of the pest. This approach will be applied to coffee in the framework of a European DeSIRA project in Uganda with local partners.