Effects of agrovoltaic shading on grapevine physiological status and stress responses

Agrovoltaics has been proposed as an innovative strategy to combine renewable energy production with agricultural activity, particularly in Mediterranean regions characterized by high solar radiation. In woody crops such as grapevine, the partial shading associated with these systems can modify the canopy microclimate and help mitigate the effects of excessive radiation on plant physiological status. However, information is still limited on how different shading systems affect the physiological response of grapevine.

In this study, we evaluated the effect of shading generated by agrovoltaic systems on the leaf physiological status of grapevine under field conditions. Three varieties (Tempranillo, Moscatel de grano menudo, and Garnacha) were studied under three treatments: an unshaded control, a shading net, and elevated solar panels installed above the vineyard, with the shading net and solar panels covering an equivalent shaded surface. Parameters related to incident radiation, photosynthetic pigment content, and different indicators of oxidative stress and antioxidant capacity in leaves were analyzed.

The results show that shading reduces incident radiation on the canopy, particularly in the upper part of the vine, and promotes physiological acclimation to lower radiation conditions. In this context, shaded plants tend to show higher chlorophyll content as a compensatory mechanism for reduced light availability. At the same time, a lower activation of mechanisms associated with light and oxidative stress was observed, with a stronger effect under the solar panel system. The response was variety-dependent, with Tempranillo and Moscatel showing higher sensitivity to shading, while Garnacha exhibited a more moderate response.

Overall, these results indicate that agrovoltaic systems, in addition to their role in energy production, may contribute to improving grapevine physiological status by attenuating the impact of excessive radiation. However, further studies are needed to assess how these physiological responses may translate into effects on yield and fruit quality. Within this context, agrovoltaics emerges as a promising approach for the adaptation of Mediterranean viticulture to scenarios of high radiation and climate change.

Keywords: agrovoltaics, grapevine physiology, radiation stress, mediterranean viticulture

Acknowledgements: This publication is part of project CPP2022-010020, funded by MCIU/AEI/10.13039/501100011033 and by the European Union “NextGenerationEU”/PRTR.