Effects of Gypsum Application at Different Levels of Nutrient Solution Electrical Conductivity on Yield, Quality and Antioxidant Activity of Soilless Strawberry Grown in Cocopeat

Research on strawberry (Fragaria x ananassa Duch.) was carried out in greenhouse in 2022-2023, arranging a 4 x 2 factorial experiment, consisting of four levels of electrical conductivity of the nutrient solutions (1.2, 1.7, 2.2, and 2.7 dS m-1) and application of gypsum (without application – control and application). The plants were grown in coconut fibre substrate from late October to early June. The 2.2 dS m-1 ECsol resulted in the highest yield, whereas the highest values of dry matter and soluble solids were recorded under 2.7 dS m-1 ECsol. Gypsum application resulted in the increase of dry matter, soluble solids, firmness and colour components. The 2.2 and 2.7 dS m-1 ECsol led to the highest levels of hydrophilic and lipophilic antioxidant activities as well as polyphenols and vitamin C. From the research carried out on strawberry grown in coconut fibre, it arose that the 2.2 dS m-1 EC of the nutrient solution showed the best effect on yield, but it did not generally differ from 2.7 dS m-1 regarding the quality of the 'fruits'. Gypsum treatment represents an effective strategy to improve some important qualitative characteristics of strawberry 'fruits', under the perspective of sustainable management of crop systems.