Abstract Using essential oils (EOs) to suppress unwanted species at the seedling stage is a promising way to decrease the use of synthetic herbicides and thus protect native plant diversity. We verified the effects of rosemary (Salvia rosmarinus) EOs at different concentrations on the growth and mortality of seedlings of the invasive alien species Acacia saligna derived from seeds collected at four wild populations in Sardinia and Sicily (Italy), by monitoring their survival, dry weight, shoot and root length during their early development. Six different spray solutions were applied to A. saligna seedlings: one with only distilled water; one with a solution of distilled water, ethanol and Tween 20; three with a rosemary EO concentration of 3.9, 7.8 and 15.6 mL/L; and one with the commercial herbicide DICOTEX© RTU. The seedling survival and growth decreased with the increase of EO concentrations; the patterns were similar for all populations. The highest rosemary EO concentration tested (15.6 mL/L) strongly inhibited shoot and root length, dry weight and survival of A. saligna seedlings and its effect was significantly different compared to the other EO and control treatments, except for the control with commercial herbicide, that was the more effective compared to all other treatments. Our results suggest that the rosemary EO concentration at 15.6 mL/L is a valid tool for the biological control of A. saligna. This treatment is promising because it could be applied primarily to reduce the seedlings’ emergence/development and establishment while ensuring the conservation of native plant diversity and the preservation of the Mediterranean habitats.

中文翻译：

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迷迭香精油对金合欢幼苗生长的毒害作用

摘要 在幼苗阶段使用精油 (EO) 抑制不需要的物种是减少合成除草剂使用从而保护本地植物多样性的一种很有前景的方法。我们验证了不同浓度的迷迭香 (Salvia rosmarinus) EO 对来自撒丁岛和西西里岛（意大利）四个野生种群的种子的外来入侵物种 Acacia saligna 幼苗生长和死亡率的影响，通过监测它们的存活率，干燥早期发育过程中的重量、枝条和根长。将六种不同的喷雾溶液施用于 A. saligna 幼苗：一种只用蒸馏水；一种含有蒸馏水、乙醇和吐温 20 的溶液；三种具有 3.9、7.8 和 15.6 mL/L 的迷迭香 EO 浓度；一种是商业除草剂 DICOTEX© RTU。随着EO浓度的增加，幼苗成活率和生长率下降；所有人群的模式都相似。测试的最高迷迭香 EO 浓度 (15.6 mL/L) 强烈抑制 A. saligna 幼苗的枝条和根长、干重和成活，其效果与其他 EO 和对照处理相比有显着差异，除了使用商业除草剂进行对照，与所有其他治疗方法相比，这是更有效的。我们的结果表明，15.6 mL/L 的迷迭香 EO 浓度是一种有效的工具，可用于生物控制 A. saligna。这种处理是有希望的，因为它可以主要用于减少幼苗的出现/发育和建立，同时确保本地植物多样性的保护和地中海栖息地的保护。