Cultivar and Plant Type Affect Yield, Fruit Quality, and Nutritional Traits in a Soilless System for Nickel-Free Strawberry Production: A Two-Year Evaluation

Recently, consumers have shown increasing interest not only in healthier food but also in products labelled as “free-from”. Among these, foods free of substances that can trigger allergic reactions in hypersensitive individuals, such as nickel, are of relevance. In this context, a two-year study was conducted in a soilless strawberry production system managed to minimise nickel inputs, to assess the feasibility of producing fruits complying with the “nickel-free” limit of 0.01 mg kg−1. The experiment involved two strawberry cultivars (‘Asia’ and ‘Arianna’) and two plant types for each cultivar (tray plants and cold-stored A+ plants), grown in a 100% perlite substrate. Productive parameters, organoleptic quality, nutritional traits, and nickel content in fruits were evaluated. The aim was to determine differences among cultivars and plant types in yield, fruit quality, and nutritional value, and to verify whether the plant type affects nickel transfer to the fruit. Yield was highest in ‘Asia’ cold-stored plants, while ‘Arianna’ tray plants showed the best qualitative profile. Fruit nickel exceeded the limit in all combinations in the first autumn, but thereafter remained below it only in tray plants, showing that plant material choice, rather than the inert substrate alone, determines the production of nickel-free fruits.