Influence of Cultivar and Fertilizer Approach on Curly Kale (Brassica oleracea L. var. sabellica). 1. Genetic Diversity Reflected in Agronomic Characteristics and Phytochemical Concentration

The objectives were to investigate if genetic diversity among field-grown traditional and F1 hybrid kale cultivars was reflected in different agronomic characteristics and consequently glucosinolate (GLS) and flavonoid glycoside concentration. This study evaluated how nitrogen and sulfur supply and biomass allocation modified phytochemicals in two experiments with combinations of three cultivars and four N and two S application levels. Results showed less growth, and higher N concentration in the traditional cultivar Tiara was associated with increased indole and total GLSs compared to traditional Hoj Amager Tofto and F1 hybrid Reflex cultivars, which exhibited higher yield, lower N concentration, and different biomass allocation. S application increased total GLS concentration, whereas aliphatic GLS percentage decreased when N application increased. Decrease of six Reflex GLSs besides quercetin glycosides and total flavonoid glycosides with increased N indicated higher N responsiveness for Reflex. In conclusion, differences in agronomic characteristics were reflected in diverse phytochemical composition.