Does Exogenous Salicylic Acid Improve Crop Yield Under Salinity?—A Meta-Analysis

Recent studies have explored the use of exogenous bio-stimulants to enhance crop growth and stress tolerance, with most focusing on growth rather than yield. This meta-analysis seeks to answer whether exogenous bio-stimulants, particularly salicylic acid (SA), can improve the yield of wheat under salinity conditions and assess its economic feasibility in wheat production. A systematic search strategy was followed by using databases such as Google Scholar and Web of Science without any restrictions on language or time to identify articles published by June 2023 (updated in April 2025). The meta-analysis found that the total yield of wheat production under stress is reduced significantly compared to the control condition, and the pooled variance is 0.67 with 95% CI (confidence interval) 0.59 to 0.76. It was also found that wheat yield improved significantly under both non-saline and saline conditions by applying exogenous SA, with the pooled estimates of 1.14 with 95% CI 1.09 to 1.19 and 1.26 with 95% CI 1.18 to 1.33, respectively. The economic analysis demonstrates that SA application is a profitable intervention for wheat cultivation in salinity-affected areas, showing an overall benefit–cost ratio of 1.295. Based on these findings and the established yield benefits, we recommend farmers apply SA at concentrations of 0.5–1 mM through foliar spraying for optimal wheat yield.