Abstract Blessed thistle (Cnicus benedictus L.) is an abundant resource with huge phytochemical and agronomic potentials. Their variation in response to agronomic techniques needs to be explored. Field studies were laid out to assess plant density and nitrogen fertilizer (N) effects on blessed thistle plant height, branches number (m-2), vegetative variables and RGR (relative growth rate), CGR (crop growth rate), LAR (leaf area ratio), NAR (net assimilation rate), as growth variables along with blessed thistle essential oil content, yield and compositions in two growing seasons. A three replicated factorial combination of plant densities (5, 10, 15, 20 and 25 plants m-2) and N levels (0, 50, 100 and 150 kg ha-1) in a randomized complete-block design were conducted. Addition of 100 kg N ha-1with 15-20 plants m-2caused a significant increase in vegetative and growth variables. Although the essential oil content declined by 28 and 39 % as N rate level rose from 0 to 150 kg ha-1, essential oil yield peaked at 40-80 kg N ha-1 in both years. The GC and GC/MS analysis showed that eicosane was the dominant component of the essential oil (31-65 %), followed by isopropyl hexadecanoate (5.7-9.2 %), octadecane (3.5-10.5 %) and cryptomerione (3.1-7.1 %) which presented variations across the treatments. Application of N resulted in a decrease in the eicosane and an increase in the proportion of isopropyl hexadecanoate, octadecane and cryptomerione. It can be concluded that optimizing agronomic management techniques could be an effective approach to improve growth, essential oil content and composition of the plant.

中文翻译：

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受植物密度和氮肥影响的有福蓟的生长、精油含量、产量和成分

摘要 有福蓟（Cnicus benedictus L.）是一种丰富的资源，具有巨大的植物化学和农艺潜力。需要探索它们对农艺技术的反应变化。实地研究旨在评估植物密度和氮肥 (N) 对有福蓟株高、分枝数 (m-2)、营养变量和 RGR（相对生长率）、CGR（作物生长率）、LAR（叶面积比），NAR（净同化率），作为生长变量以及两个生长季节的祝福蓟精油含量，产量和成分。在随机完整区组设计中进行了植物密度（5、10、15、20 和 25 株 m-2）和 N 水平（0、50、100 和 150 kg ha-1）的三个重复因子组合。添加 100 kg N ha-1 和 15-20 株植物 m-2 导致营养和生长变量显着增加。尽管随着氮含量水平从 0 增加到 150 kg ha-1，精油含量下降了 28% 和 39%，但这两年精油产量都达到了 40-80 kg N ha-1 的峰值。GC 和 GC/MS 分析表明，二十烷是精油的主要成分 (31-65 %)，其次是十六酸异丙酯 (5.7-9.2 %)、十八烷 (3.5-10.5 %) 和梧桐油 (3.1-7.1 %) ) 呈现出不同处理之间的差异。N 的应用导致二十烷的减少和十六酸异丙酯、十八烷和隐毛虫酮的比例增加。可以得出结论，优化农艺管理技术可能是改善植物生长、精油含量和成分的有效方法。