Foliar Spraying of ZnO Nanoparticals on Curcuma longa Had Increased Growth, Yield, Expression of Curcuminoid Synthesis Genes, and Curcuminoid Accumulation

Abstract

ZnO nanoparticles (NPs) can be considered a highly efficient Zn source that has been widely used in agriculture to promote crop development and productivity. The turmeric (Curcuma longa) plant has several medical properties, and its rhizome is utilized as a spice in the food sector. In this work, C. longa leaves were sprayed with various concentrations of ZnO NPs to inspect their effect on growth, yield, and bioactive compound compositions. ZnO NPs considerably increased tumeric productivity, yield, and curcuminoid content versus the control treatment. The ZnO NPs concentration of 10 mgL−1 was found to be the optimum concentration for producing the highest C. longa yields, while the concentration of 40 mgL−1 promoted positive effects on photosynthetic pigments, bisdemethoxycurcumin, demethoxycurcumin, and curcumin contents. This demonstrates that ZnO nano-fertilizer promotes plant growth, yield characteristics, and curcuminoid component synthesis, and its application is therefore notably beneficial for progressive sustainable C. longa agriculture.