CHOICE

Coordinator: DISTAL - Unibo

Scientific Officer: Brunella Morandi

Duration: 12/10/2023 - 12/10/2025

Research group: Brunella Morandi.

Sweet cherry represents a high value crop, whose cultivation is highly increasing in Italy. To reduce the risks related to both cracking and Drosophila suzukii, growers are forced to invest on protective covers. Despite a wide range of covers are available on the market, which differ for shading level, type of use and water permeability, very little is known on how they change the orchard microclimate and the trees physiological and productive performance. Therefore, despite these covers represent one of the most expensive investments when setting up a new orchard, there is still no real hints on the criteria that should drive growers’ choice. CHOICE aims at providing growers with a rational approach to optimize their cherry orchard microenvironment and physiological performance, through the correct choice of multifunctional covers, based on the vigor of their orchard and the specific environmental conditions of the growing area. This main objective will be achieved through the following specific steps: 1) Describing how different multifunctional covers (type and shading level) influence the orchard microclimate and consequently, the main physiological processes related to production performance, depending on the orchard vigor (WP1) 2) Modelling the effect of the type of cover on: i) canopy microclimate, ii) the most important physiological processes underpinning plant production (carbon assimilation and water use) (WP2). 3) Validate the model in commercial orchards having different vigor and located in different environments (Emilia-Romagna and Campania regions) (WP3) 4) Disseminate the project result to relevant stakeholders such as scientist, advisors, growers, cover producers companies etc (WP4) Activities will be carried out by 3 Research Units in close cooperation: the University of Bologna taking care of the physiological studies, the University of Modena and Reggio Emilia, taking care of the modelling and the University of Naples, contributing to the validation. CHOICE will provide technical indications to growers and advisors, and will set the basis for a decision support tool to optimize the features of the multifunctional covers for cover producers as well as for users (growers). The set up of the optimal cover will allow growers to optimize their production and investment with positive impacts on their revenue. In addition, when correctly applied, covers can represent an adaptation tool to climate change. In fact, their shading effect can reduce evapotranspiration and thus irrigation, without affecting productivity. Results are improved water use efficiency and water saving, as well as improved carbon storage. CHOICE’s technological, socioeconomical and environmental impacts are well in line with ONU Sustainable Development Goals 2 “zero hunger” and Mission 2 “Green revolution and Ecological Transition” of PNRR.

The project evaluated the effects of protective nets with different shading levels on sweet cherry physiology, productivity and fruit quality by combining field experiments carried out in Northern and Southern Italy with advanced radiative and photosynthetic modelling.

The experiments conducted by the University of Bologna demonstrated that monorow and anti-rain nets substantially improved orchard microclimate by reducing vapour pressure deficit (VPD) and atmospheric evaporative demand. Consequently, covered trees exhibited improved

plant water status, less negative stem water potential, higher stomatal conductance and enhanced photosynthetic activity compared with uncovered trees. The 20% shading treatment consistently provided the best compromise between environmental protection and carbon assimilation, whereas heavier shading (40%) produced smaller benefits. These physiological improvements resulted in enhanced fruit growth, higher yields and improved resource-use efficiency, while only minor and season-dependent effects on fruit quality were observed. Detailed analyses of xylem, phloem and transpiration flows further showed that moderate shading reduced fruit water losses without limiting daily fruit growth, contributing to a more favourable hydraulic balance during fruit development.

The trials carried out by the University of Naples confirmed that protective nets effectively mitigate atmospheric stress also under Mediterranean conditions, helping maintain physiological activity and supporting the adoption of this technology in traditional cherry production systems.

From the modelling perspective, the project developed and validated a three-dimensional radiative transfer model based on detailed digital reconstructions of tree architecture and cover systems. The model accurately reproduced light distribution within the canopy and was coupled with a carbon assimilation model to simulate the effects of different cover systems on light interception and photosynthesis at both leaf and whole-plant scales. Although further quantitative refinements are still required, the modelling framework provides a robust basis for scenario analysis and future decision-support tools aimed at optimizing orchard management under changing climatic conditions.

Overall, the project demonstrates that properly designed protective cover systems represent an effective strategy to mitigate climate-related stress in sweet cherry orchards, while improving plant physiological performance, productivity and the sustainability of orchard management. Furthermore, the integration of field experimentation with advanced modelling provides a robust scientific framework for developing predictive tools and supporting the implementation of innovative, climate-resilient orchard management strategies.