MESH - Methods, concepts and evaluation of multi-performing horticultural systems

Mesh axe team.

The research of the axis aims at designing new ways of production combining  the principles of agronomy and ecology in order to respond to environmental issues and to develop a sustainable horticulture.

The MESH axis adopts a systemic approach aiming at integrating the different components interacting in horticultural agroecosystems (i.e. crops, weeds, companion plants, crop parasites and their natural enemies, cultural practices, and environment) at different time and spatial scales.

The research objectives of the axis are:

- develop approaches and tools to design innovative horticultural cropping systems and ideotypes  

- evaluate innovative systems with regard to their agronomic, economic, environmental and socio-technical performances. Particular attention is paid to production quantity and quality criteria, to the impacts of combination of agronomic practices (introduction of companion plants, irrigation and fertilization management) on the functioning of agroecosystems, and to various ecosystem services (food production, pest regulation, water / nitrogen / carbon regulation cycles).

The axis uses different approaches and methods collaborating with the other axes of the PSH Unit:

- The integration of mathematical models developed in the Unit (link with the CQFD and CBC axes) with our knowledge on practices actually used in the field,

- Evaluation of the effects of agricultural practices, including the introduction of companion plants, on different communities of pests and natural enemies (in connection with the CBC axis)

- Analysis of conflicts and synergies between performance criteria in order to develop optimal combinations of practices. This work would lead to a tool to help designing new cropping systems that offer the best trade-offs (production, protection, soil fertility) in given production contexts and under the impact of climate change.

- Different approaches, often associated, of design and evaluation:

o A design by prototyping and the implementation of system experiments in arboriculture (peach orchard systems and a new apple/peach orchard planted in 2023) and in market gardening (experiments in laboratory and under tunnels)

o Model-assisted design through the coupling of crop models and multi-objective optimization methods allowing in silico design of technical or landscape scenarios and the search for varietal ideotypes

THESIS in MESH AXE:

• ADÈLE SAHUT:

Title: "Dynamic model for agroecology: protecting and optimizing asparagus production in the 21th century by modeling its physiology, ecology, and cultivation practices".

Financier: CIFRE scolarship

Duration: 2025 august to 2027 august

Objectives: Asparagus is an atypical perennial plant due to its strong seasonality, and it is established for a period of 10 to 15 years. Despite the specific technical requirements it entails, it has been the subject of little fundamental research or experimentation. The aim of this thesis is to improve our understanding of the physiology and ecology of this crop, with the objective of supporting the agricultural sector in the evolution of its cropping systems. We are implementing participatory protocols with growers and developing mechanistic models to better predict its seasonal growth dynamics, anticipate potential effects of climate change, and enhance our understanding of its interactions with a beetle that feeds on it—Crioceris asparagi—in an effort to manage the crop in a technically sound and sustainable way.

Partners:

INRAE

Université d’Avignon

Association Nationale de la Recherche et de la Technologie – ANRT

Association Asperges de France

Links:

https://theses.fr/s398006

https://dorian-vabre.itch.io/age-of-asparagus

• LOUNA RIZZI

Title: "Effect of the introduction and management of companion plants on volatile organic compound emissions and aphid regulation in fruit orchards".

Finances: PPR CPA Cap Zero Phyto project

Duration: 01/10/2022 to 16/12/2025

Objectives: This PhD is part of the CAP ZERO PHYTO (PPR) project, which aims to identify and combine multiple strategies to manage pests and diseases in vegetable and fruit production systems as sustainable alternatives to pesticide use. The overarching goal of the PhD is to guide the selection and management of companion plant species to enhance pest control in apple orchards by creating an olfactory landscape that both disrupts pest behavior and attracts a diverse community of natural enemies and parasitoids. The research focuses on characterizing companion plants (CPs) that emit volatile organic compounds (VOCs) capable of influencing the behavior and performance of two major aphid pests in fruit growing: the rosy apple aphid and the green peach aphid. The first phase of the PhD aims to improve the effectiveness of CPs by comparing how different management practices (nitrogen fertilization, UV-C exposure, soil disturbance practices) affect their volatile profiles and, consequently, the fecundity and orientation behavior of the target aphids. In the second phase, the most promising CPs will be tested under field conditions in a young apple orchard. The PhD candidate will characterize the resulting olfactory landscape and investigate causal links between VOC emissions, arthropod communities, tree health, growth, and production.

Links:

Video link: https://youtube.com/playlist?list=PLSt3mF9BMKU7Q0lS2NIr8n_a6wVFZYm1X&si=JSEFhJnPx1kXwr2B