The impact of plasma activated water on spinach (Spinacia oleracea L.) growth, development and content of plant bioactive compounds

The production of green leafy vegetables is an important segment in agriculture, because they are the source of functional compounds that are beneficial for human health. The main objective of this study was to determine the effects of plasma activated water (PAW) treatment on the morphological, qualitative and chemical properties of spinach under greenhouse and field growing conditions. The application of PAW has a significant influence on plant height, plant diameter, green mass and dry matter, as well as on the content of bioactive substances (phenols, flavonoids, proline) under both cultivation conditions. The results of this study show that the application of a higher dose of PAW (PAW 2) resulted in 46% higher green mass of spinach under field conditions and 57% higher green mass under greenhouse conditions compared with the control varieties. The application of PAW 2 increased the dry matter of the plants by 53% under field conditions and by 75% under greenhouse conditions compared with the control varieties. Similar results were obtained with respect to proline content under field conditions, which increased by 30% with the application of PAW 2 compared with the control varieties and by 50% in the greenhouse with the application of PAW 1. The results indicate that PAW treatment can be a useful method to improve the growth and nutritional quality in spinach cultivation under different climatic and growing conditions.