In the last decade, the kiwifruit vine decline syndrome (KVDS) has affected more than 25% of the Italian kiwifruit cultivation area, and caused the rapid death of plants or the irreversible impairment of their growth and production, with high economic losses. The root asphyxia determined by an inappropriate irrigation management or soil waterlogging, even enhanced by the ongoing climate change, certainly plays a key role in inducing the decline. Nevertheless, etiology of KVDS has not been completely unraveled and, as a result, tailored and definitive solutions to the problem have not been yet developed. KIWinner project will use a holistic approach based on the study of the interactions between soil, plant, microorganisms and environment, to identify the factor(s) triggering
and/or enhancing the decline, as well as the effects on kiwifruit plants. For the first time, the biochemical responses, oxidative status, nutrient uptake and allocation, and morphological alterations down to a (sub)micrometer scale of kiwifruit plants affected by KVDS will be assessed and compared with results obtained from control plants. The typical biometric and physiological parameters (i.e. plant growth, gas exchanges, etc.) will also be determined, in order to obtain a complete overview of the plant responses to the decline. Additionally, several agronomic solutions will be tested for their capacity to prevent or mitigate the symptoms of KVDS, and restore both plant and soil functions. Among these, new strategies as the use of biostimulants, including the beneficial rhizosphere microorganisms, and tolerant rootstocks will be tested. Trials will be performed both in the field, in an orchard characterized by the presence of KVDS at two different intensities and a similar zone with healthy vines (used as control), and in pots under controlled conditions. In the latter case, the kiwifruit decline induced by waterlogging will be in-depth investigated. The multidisciplinary expertise of the research consortium on tree crop production, plant physiology and biochemistry, soil chemistry, and plant-soil microbiology, along with the availability of adequate and innovative instrumentations, will allow pursuing the goals of the project in
the scheduled times. KIWinner outcomes will exert a positive impact on the kiwifruit producers and on the entire supply chain by reducing the economic losses due to the decline. Another potential application is the identification of plant key-responses (such as specific metabolites) to be used as early indicators of the decline. Moreover, the integrated solutions adopted to tackle KVDS will also allow restoring the soil functions and enhancing the plant resilience to climate change-enhanced stresses, in accordance with the goals of the European Green Deal and 2030 Agenda.