Project R-16121

Fruit-ReCuP: replacing copper (Cu) in biological fruit production towards alternative strategies for sustainable disease management in the biological production of apple and grapevine (Research)

The organic cultivation of multi-annual fruit crops, such as apples and grapes, is highly dependent on natural copper-based crop protection products, such as copper oxychloride. Although copper occurs naturally and is also used as a trace element in fertilizers, this causes copper to accumulate in the soil, with potentially harmful effects on soil life and surrounding fauna, as well as reduced plant uptake of nutrients. To limit risks and counteract effects on the environment and health, the EU has set limits on the use of copper as a biopesticide. This has particular implications for organic farming, where conventional agents cannot be used and copper is virtually the only means of suppressing diseases. It is therefore essential to look for alternative strategies and crop protection products that can be used in organic farming, such as resistant varieties, natural pesticides, and organic products that increase plant resistance. In the Fruit-ReCuP project, we aim to gain fundamental insights into natural biological processes that contribute to intrinsic resistance and general resilience of plants to biotic stress, as a basis for the development of new strategies for the sustainable management of pathogenic diseases in organic crop production. The focus is on the perennial fruit crops apple and grape, where we look at the functional role of plant ploidy, the surrounding microbiome, and the physiological triggers that lead to the activation of plant defenses, as well as interactions between them. Based on the principle that an increased ploidy level leads to better resilience, both tri- and tetraploid variants will be created and validated for their tolerance to important fungal pathogens. Based on comparative -omics studies, underlying molecular/biochemical mechanisms will be further characterized. In addition, the functional role of the microbiome of both the leaf and the rhizosphere in determining plant resistance will be analyzed, as well as the factors that influence this. In parallel, potential endophytes will be selected and tested for their ability to increase plant defense based on in silico analysis. In addition to microbial effects, the specific effect of polyphenols and other natural plant defense elicitors (PDEs) will also be tested for their activity against pathogenic fungi. This will also involve investigating whether this is achieved through direct antifungal activity or through the activation of natural defense mechanisms. Ultimately, the Fruit-ReCuP project will provide new fundamental insights into important endogenous and exogenous factors that increase the resistance of apples and grapes to major pathogens (i.e., scab and mildew), thereby providing alternative strategies to reduce pest pressure and improve the intrinsic resilience of the plant in order to achieve sustainable integrated disease management in organic fruit growing.

01 January 2026 - 31 December 2028