S15 - Session P1 - DEPHY EXPE ST0P Project: for the transition of current horticultural systems to agroecological systems without chemicals uses in a tropical area

Authors: Rachel Graindorge *, Joel HUAT, Luc Vanhuffel, Josian Delaunay, Marlene Marquier, Toulassi Nurbel

Horticultural systems in the various French overseas departments are often highly diversified but cultural interactions and complementarity with functional biodiversity are often little exploited. Thereby, they are more vulnerable to pest attacks and chemicals are required to protect crops. Implemented in a tropical environment, on Reunion Island, the ST0P project aims to transition current crop production systems to agroecological systems that no longer use synthetic pesticides. Thus three multi-species cropping systems are tested in CIRAD, EPL Forma'terra, and ARMEFLHOR sites. The design and composition of these production systems are the results of collective work with different stakeholders (producers, researchers, etc.). Crops and associations have been thought to activate ecosystem functions and services. Some protection strategies have already been tested and are known to aim at the "Zero chemical", while others, more innovative, will require special attention. The main levers for achieving zero pesticides are prophylaxis, plant diversification, insertion of agroecological devices, innovative physical control methods, biological control with macroorganisms, and biocontrol. The association between agriculture and livestock with poultry paths arranged in the production area is evaluated in one experimental site too. The performance is researched on different scales: economic, social, and environmental. Sharing and dissemination experiences are structural aspects of the project. After nearly two years, these agroecological systems have evolved in time and space. Economic balance is not completely obtained especially in sites where fruit production has been installed at the beginning of the project. On a social aspect, not using chemical pesticides is comfortable for growers, and production areas are pleasant to work in. Although, growers have to broaden their scope of expertise to manage these diversified croping systems with vegetable, fruit productions and sometimes livestock integration. Observations and evaluations will continue for the remaining two years to best meet the needs and expectations of producers.