Mitigating drought stress effects in tomato through seed priming and foliar application of salicylic acid: Impacts on germination and plant growth

Climate change has a detrimental impact on the agricultural sector, resulting in rising temperatures and reduced water availability, which has a direct impact on decreasing crop production and sustainability.This study aimed to evaluate the effect of seed priming and foliar application of SA on seed germination and plant growth under drought-stress conditions.This research was conducted from July to September 2024 at the laboratory and greenhouse in the Faculty of Agriculture, Brawijaya University, Malang, East Java.A Randomized Complete Block Design (RCBD) with two factors was employed in this study.The first factor was drought stress with 0 and 15% polyethylene glycol (PEG), and the second factor was salicylic acid (SA) at concentrations of 0, 50, 75, and 100 M.The results showed that PEG 6000 significantly reduced the germination rate and growth of tomato seeds.While SA priming had no significant effect on the seed germination under normal conditions, the seeds priming with SA significantly increased the germination rate, germination stress tolerance index, shoot length stress index, root length stress index, and seed vigor index under drought stress conditions.SA priming also promoted seedling growth by increasing shoot and root lengths.Furthermore, the foliar application of SA significantly improved the vegetative growth of soil-grown tomatoes under drought stress, evidenced by improvements in key growth characteristics, including plant height, number of leaves, plant biomass, RWC, and relative chlorophyll content.Notably, foliar SA application led to a thickened tomato leaves as an early drought stress response.This study demonstrated that both priming and foliar SA application could enhance plant resilience and vigor, helping to alleviate the detrimental effects of drought stress.