The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Krakow, Poland.
Faculty of Chemical Engineering and Technology, Department of Organic Chemistry and Technology, Cracow University of Technology, 31-155, Krakow, Poland.
Sci Rep. 2024 Feb 21;14(1):4313. doi: 10.1038/s41598-024-54721-6.
A proper formulation is crucial to improve the herbicidal effects of essential oils and their selectivity. In this study, we investigated the physicochemical properties of bio-based nanoemulsions (CNs) containing several concentrations of caraway (Carum carvi) essential oil stabilized with Eco Tween 80, as a surfactant, maintaining 1:1 proportions. Detailed physicochemical characteristics of the CNs revealed that their properties were most desired at 2% of the oil and surfactant, i.e., the smallest droplet size, polydispersity index, and viscosity. The CNs caused biochemical changes in maize and barnyard grass (Echinochloa crus-galli) seedlings, however, to a different extent. Barnyard grass has overall metabolism (measured as a thermal power) decreased by 39-82% when exposed to the CNs. The CNs triggered changes in the content and composition of carbohydrates in the endosperm of both species' seedlings in a dose-response manner. The foliar application of CNs caused significant damage to tissues of young maize and barnyard grass plants. The effective dose of the CN (ED, causing a 50% damage) was 5% and 17.5% oil in CN for barnyard grass and maize tissues, respectively. Spraying CNs also decreased relative water content in leaves and affected the efficiency of photosynthesis by disturbing the electron transport chain. We found that barnyard grass was significantly more susceptible to the foliar application of CNs than maize, which could be used to selectively control this species in maize crops. However, further studies are needed to verify this hypothesis under field conditions.
为了提高精油的除草效果及其选择性，合适的配方至关重要。在这项研究中，我们研究了含有不同浓度的芫荽（Carum carvi）精油的生物基纳米乳液（CN）的物理化学性质，该精油由 Eco Tween 80 稳定，保持 1:1 的比例。CN 的详细物理化学特性表明，当油和表面活性剂的浓度为 2%时，它们的性质最理想，即具有最小的液滴尺寸、多分散指数和粘度。CN 对玉米和稗草（Echinochloa crus-galli）幼苗造成了不同程度的生化变化。然而，稗草的整体代谢（以热功率衡量）在接触 CN 时降低了 39-82%。CN 以剂量反应的方式触发了两种物种幼苗胚乳中碳水化合物含量和组成的变化。CN 的叶面喷施对幼龄玉米和稗草植物的组织造成了显著损伤。CN 的有效剂量（ED，造成 50%损伤）分别为稗草和玉米组织中 CN 中的 5%和 17.5%油。喷洒 CN 还降低了叶片中的相对含水量，并通过干扰电子传递链影响光合作用效率。我们发现，稗草对 CN 的叶面喷施明显比玉米更敏感，这可以用于选择性地控制玉米作物中的这种物种。然而，需要进一步的研究来在田间条件下验证这一假设。
