Experimental on-farm precision assessment to ameliorate spraying processes and efficacy of biocontrol for diseases in viticulture – BIOSPRAYTECH

The project aims at developping BioSprayTech, a service for companies that produce and distribute biocontrol solutions for grapevine cryptogamic diseases. The objective of the service is to determine the ways to apply a chosen biocontrol solution to optimize its effectiveness in the field. This issue was identified as a technology lock by manufacturers, with experimental evidence. BioSprayTech will be based on an innovative experimental method named OFPEBAT for On Farm Precision Experiment for Biocontrol Application Techniques at TRL 4 at the start of the project. Several of the partners' previous results relating to instrumentation methods, technologies and biocontrol products developments, at TRL 6 level or higher, will be used to carry out OFPEBAT. The method will be developed up to TRL 7 through three years of experimentation and demonstration. The interactions between actors (entity that is client of results, entity providing the service, manager of estate hosting the experiment), will be formalized in order to work out the technical and organizational aspects of the service. Spraying methods will be investigated for two innovative biocontrol model products: a selected chitosan, combining stimulation of plant defenses and biofungicide action, and PROBLAD, a biofungicides by contact. The diseases considered during service maturation are downy mildew and powdery mildew.

The response of plants and pathogens is assessed using the innovative notion of functional dose, which is the dose received by the plant in relation to the leaf area. A PWM-based (pulse width modulation) variable rate sprayer configured for the experiment is used to simulate current spraying technologies in viticulture. For a given product, the OFPEBAT method will study the influence of the physical and statistical distribution of product in the canopy, of volume rate and of the granulometry.

The BioSprayTech service implemented by IFV services will be aimed at manufacturers and distributors of biocontrol products in order to optimize their recommendations. A second service BioSprayDev aimed at growers should be developed afterwards to support the validation of their new protection methods. Synthesis reports on how to apply products according to their mode of action will be distributed to raise awareness among growers and distributors about the need to change practices.

Today, fungicide treatments account for the majority of vineyard treatments. Plant defense stimulators and biofungicides are no simple substitutes to usual chemical products: specifically, application techniques need to evolve. The project will study application methods suited to each product action mode and aims to establish references that cut pesticide use indicator IFT (excluding biocontrol and sulfur) by 50% at the end of the project and to disseminate them in French wine-growing regions by 2030 with the support of the service developed. The BioSprayTech and BioSprayDev services, by developing knowledge that builds on real production practices, will contribute in the long term to the "zero pesticides" objective for 2050, which will be achieved by a combination of levers: genetics, biocontrol and agroecological practices. Plant protection companies, sprayer manufacturers and growers are expected to develop new agronomic skills. This project will contribute to this evolution.

The consortium gathers UMR ITAP and IFV, partners in UMT ECOTECH which is specialized in evaluation and design of crop protection application techniques, and UMR Agroécologie specialist in the stimulation of grapevine immunity from laboratory to field scale. Two beta-users (Phyteurop, Certis Belchim) of the service are self-financed partners, as well as SUPRAY, from Exel group, a leader in spraying, and Optima Concept (AgroSystem brand, electronics and embedded software for spraying).