S06 - Session O4 - Shading and microclimate effects on tomato yield and quality in dynamic agrivoltaic plastic greenhouse.

Authors: Noé Savalle-Gloire *, Gilles Vercambre, Jérôme Chopard, Rémi Blanchard-Gros, José Catala, Damien Fumey, Hélène Gautier

The concept of dynamic agrivoltaism involves combining photovoltaic panels and crops in the same location to provide both protection for crops from extreme events (temperature, hail, etc.) and production of electricity on agricultural land. The idea seems particularly relevant for greenhouses in Mediterranean climate because they are often shaded to protect crops and because the greenhouse structure could be a support for the panels. However, a better understanding of the effects of shading and its induced microclimate on plant growth and yield is needed to optimize panel-stirring policies. A tomato crop, grown under a dynamic agrivoltaic greenhouse was monitored during the summer 2021 in the south of France. The crop rows were grouped into 3 treatments based on similar shading time periods over the day. Microclimate was recorded over time at different heights for each treatment. Weekly harvests, fruit size and fruit marketability of each treatment were also monitored. For the photovoltaic greenhouse, there was no temperature difference between the shaded treatments and the light-scattering plastic cover reduced the differences in incident radiations. Obviously, a significant reduction in light was observed in the shaded greenhouse compared to the control greenhouse (30 % reduction). Temperature was only 1 °C lower in shaded greenhouse, however no heat wave in France occurred during summer 2021. Yield was lower in the shaded treatments, partly offset by a higher portion of marketable fruits. There was no significant production difference between shaded treatments, and no effect on fruit size either. Fruit sugar content was monitored using Degrees Brix. Those results shed new light on the agronomic interest of agrivoltaic greenhouses for tomato for panel-stirring policy. Additional measurements (plant development, vegetative growth, etc.) have been done. They will be helpful to investigate the impact of shading on the various processes leading to yield and fruit quality build-up.