Wheat productivity is constrained by genetic, agronomic, and climate factors, though it is an important crop for food production worldwide. The present study evaluated the effect of bio-fertilizer consortia and seaweed extracts on the growth and yield of two wheat varieties under different irrigation regimes in a field study. This experiment was conducted in a split-split plot based on a randomized complete block design with four replications in 2018 and 2019. Irrigation treatments were the main factor, wheat variety (Sardari and Sirvan) the subfactor, and bio-fertilizers the sub-sub-factors. The results showed that irrigation regimes significantly improved leaf width, number of leaves, fresh weight of roots and shoots, osmotic potential, leaf water content, and number of stomata respectively by 57.53, 38.59, 106.65, 135.29, 87.92, 14.22 and 13.77, 88.02 and 96.11 percent compared to dry-land conditions. Applying one- and two-times irrigation increased grain yield by 51% and 79%, respectively, and the response varied in wheat varieties. Sardari variety due to having smaller leaf dimensions (Leaf length and width) and lower fresh and dry weight of roots and shoots, as well as lower leaf and tissue water content, had lower grain yield than the Sirvan variety. All the bio-fertilizers positively impacted the growth and yield of both varieties. However, the highest average grain yield in the first and second years of the experiment (with an average of 5226.25 and 4923.33 kg/ha, respectively) were found under the combined application of Mycorrhiza + Nitrozist and Phosphozist + Seaweed extract. The results of the present study underscore the importance of irrigation regimes and consortia of bio-fertilizers for improving grain yield. This study also highlighted the resilience of the studied wheat varieties and bio-fertilizers to projected climate changes. These findings could provide insights into adaptive strategies for mitigating the impact of climate change on wheat production.
