Physiological responses and antioxidant properties of spiny coriander (Eryngium foetidum L.) under shading and nitrogen fertilization

The objective of this study was to evaluate the effects of light and nitrogen fertilization on the fresh mass, essential oil contents, mineral contents, and antioxidant compounds in leaves of spiny coriander (Eryngium foetidum L.). Yield was influenced by luminosity and fertilization conditions, with a 37% increase in leaf fresh mass and higher levels of total phenolics, flavonoids, and antioxidant activity and production of essential oil in full sun conditions. Cultivation in 50% shading induced higher levels of chlorophyll b, carotenoids, and minerals (N, P, K, S, B, and Cu) in addition to lower dry mass content, which are desirable characteristics for fresh consumption. DPPH inhibition decreased with increasing nitrogen fertilization in 50% shading. Considering the productivity, essential oil, and antioxidants, open field cultivation provides the most appropriate conditions for the production of spiny coriander for food, functional supplements, and pharmaceuticals. Shading is recommended for production aimed at fresh markets due to the quality of the leaves.