Evening Primrose (Oenothera biennis L.) is an industrial crop-producing seed with high oil concentration characterized by high gamma-linoleic acid. However, limited information is available on its response to the nutrient supply, especially P and K. The aim of this work was to compare the response of Evening Primrose to the application of N, P, and K alone or in combination in a P and K deficient soil in terms of grain yield, yield components, and oil composition in comparison to Rapeseed (Brassica napus L.). Evening Primrose yielded 54.4% less seed and 67.3% less oil than Rapeseed. Such differences were reduced when nutrients, especially N or P, were applied. N stimulated Evening Primrose more than Rapeseed. Application of K favored Evening Primrose oil yield when no N or P were added, and this especially occurred by an enhancement of the pod number. P favored yield per pod and oil yield in the Evening Primrose more than Rapeseed in almost all conditions. Fertilization scarcely affected lipid composition. In particular, an increase in the oleic acid concentration was found only when N + K or N + P + K were applied compared to the sole N or sole K applications. These results suggest that P and K differentially influenced yield components of both species and that Evening Primrose was less adapted than Rapeseed to a scarce nutrient supply.

中文翻译：

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地中海地区的 N、P 和 K 供应差异调节月见草和油菜籽产量成分和粮油浓度

月见草 ( Oenothera biennis L.) 是一种具有高油浓度的工业作物种子，其特征是高 γ-亚油酸。然而，关于其对养分供应，尤其是 P 和 K 的反应的信息有限。这项工作的目的是比较月见草对单独施用 N、P 和 K 或在 P 和 K 中组合施用的反应。与油菜籽相比，在谷物产量、产量成分和油成分方面缺钾的土壤（欧洲油菜）L.）。月见草产生的种子比油菜籽少 54.4%，油少 67.3%。施用养分，尤其是 N 或 P 后，这种差异会减少。N 比油菜籽更能刺激月见草。当不添加 N 或 P 时，施用 K 有利于月见草油产量，尤其是通过增加豆荚数来实现这一点。在几乎所有条件下，P 对月见草的单荚产量和油产量的影响都超过油菜籽。施肥几乎不影响脂质组成。特别是，与单独施用 N 或单独 K 相比，仅在施用 N + K 或 N + P + K 时才发现油酸浓度增加。这些结果表明，P 和 K 对两种物种的产量构成影响不同，而且月见草比油菜更不适应稀缺的养分供应。