Investigation of Salt Stress in Rosemary (Rosmarinus officinalis L.) with the Remote Sensing Technique

Abstract

In the present work, the effect of different salt concentrations on growth and quality of rosemary (Rosmarinus officinalis L.) was investigated using ground-based remote sensing techniques under greenhouse conditions in 2018. The experiment was carried out in a randomized complete block design with three replications and lasted 8 weeks in total. Spectroradiometer measurements were performed on the leaves of rosemary plants to monitor changes in spectral signatures due to salt stress. Spectrophotometer and chlorophyll meter measurements were also taken from the leaves of the plants to investigate the reactions to salt stress at the end of 4th and 8th weeks simultaneously with all other measurements. According to the obtained data, there was a significant difference in the chlorophyll, brightness and colour values of the leaves in response to salt stress, and a difference was observed in the reflective values of the plants in the spectral measurements taken at 4th and 8th weeks. The region with the biggest difference between reflectance values was near-infrared among different salt concentrations applied plants. In the 4th week, the most vivid color (intense green) was obtained in the S3 and S4 applications, (19.80 and 19.40, respectively). However, as the stress application time and the applied salt rate increased, small changes in plant color occurred. Besides, it was concluded that salt treatment increased the NDVI (Normalized Difference Vegetation Index) values of the plants.

Keywords

• salt stress
• spectral measurement
• rosemary
• chlorophyll measurement