Fennel is one of the most significant medicinal and aromatic herbs. It is used as a culinary ingredient and has an essential role as a raw material in the pharmaceutical industry. Many researchers across the world are working to increase the active components in the essential oil of medicinal and aromatic plants under organic farming. Growth promoters are one of the most effective methods for stimulating secondary metabolite production under organic agriculture. The objectives of this study were to investigate how foliar sprays of yeast extract (Y) and/or chitosan-oligosaccharide (CHO) affected the growth and yield of organic fennel (Foeniculum vulgare spp. vulgare Mill.) and if these applications can stimulate the production of pharmaceutical active ingredients in fennel fruits. Fennel foliage was subjected to foliar spray of Y at concentrations of 0 (Y0), 2 (Y1), and 4 (Y2) g L⁻¹, and CHO at concentrations of 0 (CHO0), 60 (CHO1), and 120 (CHO2) mg L⁻¹ twice. The results revealed that both Y and CHO treatments promoted growth parameters and leaf pigments content. Total phenols and nutritional content (N, P, K, Ca, and Mg) in fennel fruits were also improved. Furthermore, Y and CHO treatments enhanced fruit and oil productivity. Foliar spraying with Y and/or CHO, as well as their combination, resulted in significant modification in main pharmacological active components in fennel essential oil. Treated plants with Y1 had the lowest proportion of estragole (24.61 %), an undesirable component in fennel oil, and the highest concentration of anethole (64.50 %), which improved the oil quality. While treated plants with CHO1 or CHO2 displayed an increase in estragole content by about 33.34 and 46.59 % compared with Y1-plants, respectively.

These new findings demonstrated that applying Y2 or CHO at both levels not only increased fennel growth and yield, but also contributed to increasing estragole and decreasing anethole concentration, and both had a negative impact on essential oil quality. However, applying Y1 enhanced fennel productivity as well as essential oil quality.

茴香是最重要的药材和香料之一。它用作烹饪原料，并在制药工业中作为原材料发挥重要作用。世界各地的许多研究人员正在努力增加有机农业下药用和芳香植物精油中的活性成分。生长促进剂是在有机农业下刺激次级代谢产物生产的最有效方法之一。本研究的目的是调查酵母提取物 (Y) 和/或壳寡糖 (CHO) 的叶面喷洒如何影响有机茴香 ( Foeniculum vulgare属 vulgare Mill.) 以及这些应用是否可以刺激茴香果实中药物活性成分的产生。对茴香叶进行叶面喷洒，其中 Y 浓度为 0 (Y0)、2 (Y1) 和 4 (Y2) g L ^-1，CHO 浓度为 0 (CHO0)、60 (CHO1) 和 120 ( CHO2) mg L ^-1两次。结果表明，Y 和 CHO 处理均促进了生长参数和叶色素含量。茴香果实中的总酚和营养成分（N、P、K、Ca 和 Mg）也得到了改善。此外，Y 和 CHO 处理提高了水果和油的生产力。叶面喷洒 Y 和/或 CHO 以及它们的组合，导致茴香精油中主要药理活性成分的显着改变。用 Y1 处理的植物具有最低比例的草蒿脑（24.61 %），这是茴香油中的不良成分，而茴香脑的浓度最高（64.50 %），从而提高了油质。虽然与 Y1 植物相比，用 CHO1 或 CHO2 处理的植物显示出草蒿脑含量分别增加了约 33.34 和 46.59 %。

这些新发现表明，在这两个水平上施用 Y2 或 CHO 不仅可以增加茴香的生长和产量，还有助于增加草蒿脑和降低茴香脑浓度，并且两者都对精油质量产生负面影响。然而，应用 Y1 提高了茴香的生产力以及精油的质量。