To study the effects of foliar application of auxin (indole acetic acid) on the morphophysiological and biochemical characteristics of safflower cultivars under water-deficit stress (WDS) condition at the end of the growing season, an experiment was performed using split-plot factorial in the form of randomized complete block design with three replicates during the 2018–2019 and 2019–2020 crop seasons. The main factor of this experiment was water-deficit stress in two levels, i.e., normal irrigation (control) and irrigation cut-off at flowering stage, and two sub-factors include safflower cultivars (Golmehr and Goldasht) and foliar application of auxin in two levels, i.e., no application and applying 4 g.L⁻¹ auxin. Water stress decreased bush heights, grain weight, grain yield, biological yield, harvest index, SPAD index, contents of oil, palmitic acid, linoleic acid, and oleic acid and increased proline content and activities of antioxidant enzymes such as catalase and peroxidase. In comparison with the Golmehr cultivar, the Goldasht cultivar had a higher number of grains (13.27%), grain yield (32.42%), and biological yield (34.29%). Higher bush height (15%), oil percent (9.58%), linoleic acid (30.76%), and oleic acid content (19.59%) were observed in Golmehr cultivar. Under WDS, the activities of antioxidant enzymes and proline in the two cultivars did not change significantly; however, under WDS, meanwhile, Goldasht cultivar showed higher catalase (12%) and peroxidase (13.5%) activities and proline (11.04%). Since using auxin alleviated the side effects of WDS through increasing SPAD index (2.51%), proline content (17.93%), and activities of catalase (30.53%) and peroxidase (14.72%) enzymes, auxin application can be recommended for alleviating the effects of WDS.

为了研究在生长季结束时叶面施用生长素（吲哚乙酸）对缺水胁迫（WDS）条件下红花品种形态生理和生化特性的影响，进行了裂区因子分解实验。随机完整块设计的形式，在2018–2019年和2019–2020年作物季节重复进行三次。该实验的主要因素是两个阶段的缺水胁迫，即正常灌溉（控制）和开花期的灌溉截止，而两个次要因素包括红花品种（Golmehr和Goldasht）以及在植物中叶面施用生长素。两个级别，即不应用和应用4 gL ^-1生长素。水分胁迫降低了灌木丛的高度，谷粒重量，谷粒产量，生物产量，收获指数，SPAD指数，油，棕榈酸，亚油酸和油酸的含量，脯氨酸含量增加，抗氧化酶（如过氧化氢酶和过氧化物酶）的活性增加。与Golmehr品种相比，Goldasht品种具有更高的谷物数量（13.27％），谷物产量（32.42％）和生物产量（34.29％）。在Golmehr品种中观察到较高的灌木高度（15％），油百分比（9.58％），亚油酸（30.76％）和油酸含量（19.59％）。在WDS条件下，两个品种中抗氧化酶和脯氨酸的活性没有显着变化。然而，在WDS下，Goldasht品种显示出较高的过氧化氢酶（12％）和过氧化物酶（13.5％）活性，脯氨酸（11.04％）。