Israël Tankam Chedjou

PhD

Israel Tankam Chedjou
  • University of Yaoundé I, Cameroon, Dec. 2015-April 2021
  • Title: Modelling, analysis and control of plantain plant-parasitic nematodes
  • HAL: tel-03217816
  • Supervisors: J. J. Tewa, S. Touzeau, F. Grognard
  • Partners: CIRAD, Centre africain de recherches sur bananiers et plantains (CARBAP)

Context

Banana trees
Banana trees, Yotetang, CC BY-SA 4.0
Banana toppling
Banana toppling
Banana burrowing nematodes
Infested roots
Banana burrowing nematodes (Radopholus similis)
  • Banana, including plantain: major staple food – Cameroon: 2% GDP
  • Burrowing nematodes Radopholus similis
    • develop, feed and reproduce in roots
    • severe crop losses, up to banana toppling
  • Control methods
    • nematicides: harmful to environment and human health
    • cropping practices based on soil sanitation, including fallows
    • tolerant or resistant banana varieties

Objectives

  • Develop a model describing plant-parasitic nematode damages in a plantation
  • Design efficient and sustainable control strategies to limit damages, based on fallows

Results

Seasonal banana-nematode interaction model

Model diagram
  • Hybrid system to describe plant growth: roots only grow until flowering; plant replaced either by a lateral shoot, or by a new sucker at the end of each cropping season
  • Yield proxy based on healthy roots
  • Model analysis assuming fast root infestation dynamics
  • Conditions on pesticide load or fallow to ensure nematode extinction

I. Tankam Chedjou, S. Touzeau, F. Grognard, L. Mailleret, J.-J. Tewa. A multi-seasonal model of the dynamics of banana plant-parasitic nematodes. In: CARI’2018 – 14th African Conference on Research in Computer Science and Applied Mathematics, Stellenbosch, South Africa, 2018. HAL: hal-01871510v1

I. Tankam Chedjou, S. Touzeau, L. Mailleret, J.-J. Tewa, F. Grognard. Modelling and control of a banana soilborne pest in a multi-seasonal framework. Mathematical Biosciences 322:108324, 2020. DOI: 10.1016/j.mbs.2020.108324. HAL: hal-02775460

Optimisation of fallow deployment

  • Agricultural control: constant or variable fallow periods, which reduce the nematode population in the soil (no host to feed and reproduce)
  • Aim: maximise the cumulated yield (reduced by the nematode population), while minimising the costs of nursery-bought pest-free suckers, on a fixed time horizon that lasts several cropping seasons
  1. Systematic use of pest-free suckers and fallows between two cropping seasons

I. Tankam Chedjou, F. Grognard, J.-J. Tewa, S. Touzeau. Optimal and sustainable management of a soilborne banana pest. Applied Mathematics and Computation 397:125883, 2021. DOI: 110.1016/j.amc.2020.125883. arXiv 2020: 2007.12606. HAL: hal-03111065

  1. Occasional use of pest-free suckers and fallows to reduce costs; otherwise lateral shoot kept after plant uprooting for the next cropping season

I. Tankam Chedjou, F. Grognard, J.-J. Tewa, S. Touzeau. When and how to fallow: first steps towards banana crop yield improvement through optimal and sustainable control of a soilborne pest. Journal of Interdisciplinary Methodologies and Issues in Science, Digital Agriculture in Africa, 2021. DOI: 10.18713/JIMIS-120221-8-4. HAL: hal-03103785

Misc

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