Impact of Fortified Nano Zinc and Iron Composite Capsules on Growth, Yields and Nutrients Accumulation in Cabbage (Brassica oleracea var. capitata L.) and Cauliflower (Brassica oleracea var. botrytis L.)

Synthesized composites were characterized through UV-spectrophotometer, XRD, SEM, EDX and FTIR analysis. SEM and EDX images confirmed surface morphology of ordinary mesoporous nano silica (mNs) and Fe & Zn embedded mNs. In XRD pattern of mNs peaks absence indicate that nano silica synthesized by sol-gel method was amorphous whereas reduced graphene oxide (rGO) synthesized in crystalline form. FTIR spectra of Zn and Fe loaded mNs and rGO showed that encapsulation of zinc and iron by mNS and rGO was successful. Results of experiment indicate, twice foliar application of 60 ppm Zn+ 30 ppm Fe through mNs (T6) and 40 ppm Zn+20 ppm Fe through rGO (T8) exhibited significantly higher economic and biological yields of both crops over conventional and Control. With increasing doses of nano zinc and iron through mNs composite capsules, significant increase in nutrients content and uptake by cabbage and cauliflower was observed in comparison to control. Whereas, increasing doses of nano zinc and iron application through rGO lead to a considerable reduction in nutrient content and thus hamper their uptake. Thus, T6 and T8 treatments were best pronounced in terms of yields, nutrients uptake and enriching biomass by iron and zinc content in cabbage and cauliflower, respectively. Compared to control, quality of cabbage head and cauliflower curd biomass in terms of Fe and Zn content, protein and phenol content were significantly more with 40 ppm Zn+20 ppm Fe (T8) and 60 ppm Zn+30 ppm Fe (T6) through rGO and mNs , respectively. Available zinc and iron in soil was unaffected by application of zinc and Fe through mNs and rGO in crops.