The influences of various sulfur and nitrogen fertilizers were evaluated on safflower agronomic traits and fatty acid profile. The fertilizer treatments were sulfur as S1 (no usage), S2 (25 kg ha-1 sulfur from sulfur phosphate, SP), S3 (50 kg ha-1 sulfur from SP), S4 (25 kg ha-1 sulfur from elemental sulfur, ES), S5 (50 kg ha-1 sulfur from ES), S6 (25 kg ha-1 sulfur from zinc sulfate, ZS), S7 (50 kg ha-1 sulfur from ZS) as well as nitrogen usage as N0, N40 and N80 (0, 40 and 80 kg ha-1 nitrogen) in form of urea which were tested in Baneh, Iran at 2021. The entry by tester (treatment by trait) biplot which explained 73% of the variability indicated that the N80-S7 was the best treatment for obtaining higher values for most traits like yield and oil performance as well as some fatty acids like linolenic acid. Some other unsaturated fatty acids like oleic, linoleic and arachidic acids were increased under N0-S5 treatment. Also, fatty acid profile-related traits, oil and protein properties were positively related similar to the positive correlations among agronomic traits. According to the distinction and typical abilities, N80-S7 followed by N80-S4 were detected. Based on the discriminative ability of trait, stearic acid, oil, harvest index and capitulum per plant had high discriminating ability. The current investigation underscores the positive impact of sulfur and N on safflower characteristics and emphasizes the joint application to enhance safflower performance in upland semi-arid regions regarding the best treatment as N80-S7 (80 N and 50 kg ha-1 sulfur from ZS, respectively).
