Enhancement of "Carosello Scopatizzo" (Cucumis melo L.) through the adoption of a cultivation system with high water and nutrient use efficiency.

For more than twenty years, the horticulture research group at the University of Bari has been engaged in various activities, including the study and application of soilless cultivation systems characterized, among other aspects, by high plant densities and efficient water resource utilization. Generally, these systems are adopted for the cultivation of hybrid cultivars characterized by high uniformity and productivity. In fact, in reference to these cultivation systems, there is often talk of industrialized agriculture. Both "industrialized agriculture" and "precision agriculture" are not "enemy" terms to the conservation of agro-biodiversity, but rather cultivation systems that can also enhance local varieties like the 'Carosello Sopatizzo' (Cucumis melo L.). In the experimental activity carried out in a greenhouse at the experimental farm "La Noria," ISPA-CNR in Mola di Bari, the 'Carosello Scopatizzo' was cultivated with the Nutrient Film Technique (NFT) in a closed-loop system, during the spring-summer period, with a nutrient solution consisting of three levels of NaCl concentration (0, 2.5 mM, and 5 mM) starting from rainwater and it was examined how the concentration of this salt influences cultivation, productivity, and fruit quality. It emerged that increasing the concentration of NaCl in the circulating nutrient solution in the NFT system led to an increase in electrical conductivity up to 8 dS·cm-1, without a significant decrease in yields or fruit size. Furthermore, the NFT cultivation technique allowed for a rapid onset of production, with the first harvest taking place 26 days after transplanting. In the three experimental treatments, at 60 days after transplanting, each "Carosello Scopatizzo" plant produced an average of 16 fruits with an average weight of 200 g, resulting in a production of 3.2 kg per plant. Furthermore, plants produced an average of 3.2 g of biomass per liter of absorbed nutrient solution, which means that for every kilogram of harvested product, the consumption of nutrient solution was approximately 35-40 L, compared to over 100 L/kg of harvested product in open-air cultivation. NFT proved to be a suitable technique for the enhancement of "Carosello Scopatizzo," even though it requires technical knowledge not widely spread among farmers. Among the objectives of this activity are also the nutritional characterization of "Carosello Scopatizzo," the production of small entirely edible fruits, the analysis of macro and micronutrient removal to optimize fertilizer use, and the development of non-destructive assessments (NIR technology) for qualitative fruit selection.