Indirect effects of plasma-activated water to two-spotted spider mites [Tetranychus urticae (Acari: Tetranychidae)] depend on crop species

Plasma-activated water (PAW) technology is receiving increased attention as a booster of seed germination, seedling vigor, and some studies have described its potential to manage crop pathogens. In a recent study, we demonstrated that PAW can also be used as a sustainable component to improve tomato plant resistance to two-spotted spider mites Tetranychus urticae Koch (Acari: Tetranychidae). However, the applicability of this technology across a broader range of crop species remains largely unexplored. Here, we investigated indirect effects of two PAWs (referred to as PAW 6.0 and 9.4 min with atmospheric plasma jet) on three additional crop species (soybean, marigold, and strawberry) to two-spotted spider mites. For each crop species, two-leaf stages were supplemented daily with 50 mL of each PAW as irrigation, and results were compared with untreated control plants. Population growth of two-spotted spider mites on different plant treatments was monitored over two weeks. Results revealed that both PAW 6.0 and PAW 9.4 irrigated plants of soybean and marigold significantly reduced two-spotted spider mite populations compared to their respective control plants. Conversely, no significant differences were observed in the population growth of two-spotted spider mites between PAW irrigated strawberry plants and control plants. Results presented in this study support the hypothesis that indirect effects of supplementary PAW irrigation in enhancing plant resistance to two-spotted spider mites can vary depending on crop species.