Investigating the effect of seed priming and foliar application of seaweed extract and salicylic acid on thymus under drought stress

Considering the importance (Thymus vulgaris L.) and the effects of seaweed extract and salicylic acidpriming in increasing drought resistance at different stages of plant growth, an experiment was done as a factorial layout based on a completely randomized factorial design with three replications in the research greenhouse of Jiroft University (2020).

Three levels of 100% (control), 50%, and 35% field capacity were considered as test factors for drought treatment, seed preparation and seedling spraying including zero (control), 0.3%, 3.5%, and 1% algal extract and 1mM salicylic acid, 2 mM salicylic acid and composition of algae, and salicylic acid extract were considered as second factors.

The results of this study showed a significant difference in examined factors such as germination rate, root, and shoot length and root and shoot weight treatment at a 1% probability level and in drought stress treatment of 35%, salicylic acid priming treatment had the best performance with an improvement of 6 traits compared to the control. The results of the foliar application of seedlings also showed that the highest shoot weights of seedlings were under the combined treatment of algal extract plus salicylic acid treatment.

General results showed that priming and foliar spraying with salicylic acid had been more effective than algae extract on plant drought resistance, and of course, the combined treatment of salicylic acid and salicylic acid extract plus algae extract with a higher concentration is able to improve plant resistance to drought in the vegetative stage.