Antioxidant activities of phenolics, flavonoids and vitamin C in two cultivars of fennel (Foeniculum vulgare Mill.) in responses to organic and bio-organic fertilizers

Field experiment was conducted to study the effect of organic and bio-organic fertilizers on dry weight; yield, total phenolics (TPC), total flavonoids (TFC), vitamin C and on their antioxidant activities of two sweet fennel cultivars Dolce and Zefa fino. Results strongly showed that there were significant differences between sweet fennel cultivars. Generally the highest values of all parameters were obtained when fennel plants were supplemented with 50% NPK + 50% organic fertilizer and bio fertilizer when compared with control treatment. The highest values of TPC, TFC and Vit. C were recorded by Zefa fino cultivar when received 50% NPK + 50% organic treatment. The antioxidant activities of both cultivars were evaluated and Dolce cultivar showed the highest DPPH scavenging activity expressed as IC50 compared with Zefa fino cultivar. In addition, Dolce cultivars exhibited the highest value for Fe2+-chelating activities for organic and bio-organic fertilizers followed by Zefa fino when compared to control treatment. Dolce cultivar generally showed superiority than Zefa fino in all measured parameters.