Zinc Fortification and Yield Enhancement of Eggplant Fruits: Combined Effects of Plasma Seed Treatment and PAW Foliar Spray

Abstract

Eggplant (Solanum melongena L.) seeds were treated by a gliding arc air-ZnSO4-H2O plasma jet for the fortification of Zn into the seed. To find the maximum seed germination percentage, seeds were treated for 2, 4, 6, and 8 min with the plasma seed processing system. 6-min seed plasma seed processing condition provided the highest germination rate of ~ 88% compared to the control of ~ 68%. Air plasma-activated water (PAW) was sprayed 2, 4, 6, and 8 times on the plant cultivated from the 6-min-treated seeds. Concentrations of Zn, Ca, and Fe along with growth characters, enzymatic activities (CAT, APX, and SOD), total content of phenol (TPC), sugar (TSS), and protein (TSP) (total soluble) were estimated to explore the underlying mechanisms involved due to seed treatment with Zn and spray of PAW on the plant. The findings show that the fortification of Zn into eggplant seeds and the foliar spray of PAW contributed to the enhancement of growth metrics as well as increased the concentrations of antioxidant enzymes, TPC, TSS, TSP, and minerals. Besides, the yield of eggplant fruits was also enhanced due to the fortification of Zn and PAW foliar spray. The results presented might offer a sustainable alternative to plasma-processed Zn fortification instead of traditional farming of eggplants.