Plasma-activated water (PAW) is receiving increased attention as a booster of seed germination and seedling vigor, and some studies have described use of PAW to manage crop pathogens. Here, we examined physicochemical properties of two PAWs (referred to as PAW 6.0 and 9.4 min with atmospheric plasma jet) and assessed “their indirect effects” (applied as supplementary irrigation) on host suitability of tomato plants (Solanum lycopersicum L.) to two-spotted spider mites (Tetranychus urticae Koch). Exposure of water to cold plasma significantly lowered pH and increased concentrations of H₂O_2, NO₂⁻, and NO₃⁻. Supplementary PAW irrigations elicited significant increases in leaf composition of several elements (N, P, K S, Ca, and Mg), leaf reflectance, plant size, and trichome densities (except non-glandular trichomes on the adaxial surface). Preference bioassays revealed significant avoidance of settling and reduced oviposition by two-spotted spider mites on leaf discs from PAW-irrigated plants compared to those from untreated control plants. Performance bioassays showed a significant decrease in two-spotted spider mite populations on PAW-irrigated plants. Results presented in this study provide comprehensive support to the hypothesis that indirect effects of supplementary PAW irrigation significantly reduce host plant suitability to two-spotted spider mites. PAW 6.0 may be slightly better than PAW 9.4, and this difference in performance is discussed in this study. Applications of PAW as supplementary irrigation are likely highly compatible with other IPM tactics and should be considered an innovative and sustainable component in twenty-first-century pest management.

等离子体活化水 (PAW) 作为种子发芽和幼苗活力的促进剂越来越受到关注，一些研究描述了使用 PAW 来控制作物病原体。在这里，我们检查了两种 PAW（用大气等离子射流称为 PAW 6.0 和 9.4 分钟）的理化特性，并评估了“它们的间接影响”（用作补充灌溉）对番茄植物 ( Solanum lycopersicum L.)的寄主适宜性。 -斑点叶螨（Tetranychus urticae Koch）。将水暴露于冷等离子体会显着降低pH值并增加H ₂ O _{2 、} NO ₂ ^-和NO ₃ ^-的浓度。补充 PAW 灌溉显着增加了叶片中多种元素（N、P、KS、Ca 和 Mg）的组成、叶片反射率、植株大小和毛状体密度（除了近轴表面上的非腺体毛状体）。偏好生物测定显示，与未经处理的对照植物相比，PAW 灌溉植物的叶盘上的二斑叶螨明显避免了沉降并减少了产卵。性能生物测定显示 PAW 灌溉植物上的二斑叶螨数量显着减少。本研究中提出的结果为以下假设提供了全面的支持：补充 PAW 灌溉的间接影响显着降低了寄主植物对二斑叶螨的适宜性。 PAW 6.0 可能比 PAW 9.4 稍好，本研究中讨论了这种性能差异。 PAW 作为补充灌溉的应用可能与其他 IPM 策略高度兼容，应被视为二十一世纪害虫管理的创新和可持续组成部分。