S06 - Session O9 - Potentialities of a biogenerator applied to nutrient solutions in a soilless tomato crop

Authors: Landry Rossdeutsch *, Serge Le-Quillec, Irène Gérondeau, Denis Loda

The CTIFL (Carquefou, France) in partnership with the company Divatec, has developed a biogenerator applied to nutrient solutions in a soilless tomato crop. The objectives are to increase the resilience of soilless system against pathogens, to improve fertilization efficiency, and to boost agronomic performance. Inspired by aquaponics cultivation, the principle is to create a nitrifying filter promoting the development of potential beneficial plant bacteria. The solution enriched with living organisms is then used to make regular nutrient solutions and provided daily to the plant by drip irrigation. Plant architecture (plant growth, stem diameter, leaf area index, roots density), agronomic parameters and yield were measured over two years (2020 to 2021) in comparison with conventional irrigation system using UV disinfection. Development of Agrobacterium rhizogenes was evaluated at the end of each growing season by a visual inspection of rockwool slabs. Using the biogenerator instead of the traditional UV disinfection increased both vegetative and generative vigor as seen on growth (6%), stem diameter (8%), leaf area index (18%), marketable yield (6.4%) and average fruits weight (5.6%). Biogeneratior treatment significantly reduced the frequency of presence and heavy roots colonization by Agrobacterium rhizogenes . Results demonstrated that the developed biogenerator has a positive economic and sanitary impact on soilless tomato crop. However, excessive vegetative vigor is not suitable in commercial production and thus require climatic adjustment to optimize yield response. Although only 10% of N consumption was originated from organic nutrition, this approach opens a new research era on organic nutrition in commercial soilless production.