A field experiment was conducted to assess the effect of the combined use of different soil amendments and foliar application of plants’ hormone-like substances on the growth, yield, phonological and morpho-physiological traits of spring wheat in a semi-arid region at Maragheh in northwestern Iran (37° 23ʹ N, 46° 16ʹ E; 1,485 m) during the growing season of 2017–2018. Twelve treatments comprising factorial combinations of four kinds of fertilizers (no-application, humic acid at 20 kg ha-1, farmyard manure at 20 t ha-1, and chemical complete fertilizer contained 11 essential elements at 5 L ha-1) and three growth regulators (distilled water as check, 200 ppm salicylic acid, and 200 ppm ascorbic acid) were compared in a spilt plot in randomized complete block design with three replications. The farmyard manure (FYM) was applied in the autumn and was ploughed down immediately after application. Results showed that FYM application significantly (P < 0.01) increased the plant growth and seed yield since the highest chlorophyll content (54.98 ± 1.96), number of days to anthesis (97.00 ± 4.33 days), canopy width (11.08 ± 0.36 cm), number of spikes per area (516.60 ± 89.62 spikes m-2), number of glumes per spike (33.15 ± 3.84 glumes), seed protein content (13.72 ± 0.15%) and seed yield (4,353.30 ± 259.92 kg ha-1) were recorded for plants grown under applied FYM. Assessment of phenological traits revealed that application of FYM delayed maturity. Although both foliar application of salicylic acid and ascorbic acid increased the studied characteristics compared to the control, the highest amount of 1,000-seed weight (46.34 ± 1.41 g), spike length (10.80 ± 1.09 mm), seed protein content (13.38 ± 0.16%), chlorophyll content (50.41 ± 2.36) and the amount of photoassimilate remobilized to the grain (3.72 ± 0.34 g plant-1) was observed in plants sprayed with salicylic acid. Based on the obtained results, it can be suggested that due to the poor physicochemical conditions of the so
