Optimising plasma-activated water applications for enhanced growth and antioxidant capacity in maize hybrids: a comparative study of kernel priming, cultivation, and foliar application

Abstract Cold atmospheric plasma (CAP) and plasma-activated water (PAW) have emerged as promising tools with potential applications in the agricultural sector. The reactive oxygen and nitrogen species present in CAPs and PAWs have been reported to promote seed germination, enhance plant growth, and improve stress tolerance. The objective of this study is to investigate the effects of PAW on selected maize hybrids, focusing on its application methods, including kernels priming, short cultivation, and foliar application. The application of PAW for kernel priming significantly enhanced growth, with improvements noticed in root and shoot length, leaf area, fresh weight, water uptake, and accelerated lignification. Additionally, an increase in carotenoid and phenolic concentrations was observed in the leaves. When PAW was applied during cultivation, minimal improvements were observed compared to cultivation with tap water. Further, foliar application of PAW was observed to increase carotenoid content in the leaves, enhancing antioxidant capacity. This application also yielded the most notable outcomes in terms of growth parameters and carotenoid concentrations. On the other hand, it did not affect the activity of guaiacol-peroxidase, nor did it influence the concentration of phenolics and chlorophylls. These findings collectively suggest that PAW may be beneficial for enhancing antioxidant capacity in maize, potentially improving resilience under abiotic stress. Further research into the optimization of PAW composition and timing of its application could maximise these benefits, contributing to more sustainable crop production.