Effects of foliar and root application of Zn and Fe bio-nanofertilizers on the glucosinolate, Zn and Fe contents of Pak choi (Brassica rapa Subsp. Chinensis) grown under hydroponic and pot cultivation

Pak choi is a rich source of minerals and health beneficial compounds such as glucosinolates (GSLs). This study is focused on implementing sustainable agronomic approaches to optimize pre-harvest cultivation and improve plant growth and nutritional value. Therefore, the aim of this work was to evaluate the effect of foliar and root fertilization of algae capped ZnO and ¿-Fe2O3 nanoparticles on the growth and content of GSLs, Zn and Fe of Pak choi grown under hydroponic floating system and pot conditions. The foliar application of ZnO (77 nm) and ¿-Fe2O3 (68 nm) nanoparticles functionalized with an Arthrospira platensis extract increased fresh weight (39.71 %), plant height (42.77 %), leaves number (26.47 %), root length (33.33 %), and Zn (10-fold) and Fe (2-fold) contents in hydroponic plants. The same treatment also improved plant fresh weight (31.73 %), and Zn (6-fold) and Fe (2-fold) in pot cultivated Pak choi. Six GSLs were detected, which were also enhanced by the joint application of nanoparticles and microalgae extract. The results revealed a high synergy between the ZnO- and ¿-Fe2O3 nanoparticles and the A. platensis extract to increase plant growth and Zn and Fe micronutrients and glucosinolates in Pak choi grown under hydroponic and pot systems. © 2024 The Author(s)