Effect of spraying algae extract on the performance of rosemary plants irrigated with different concentrations of saline water

The impact of salinity NaCl and algae extract (AE) on various growth characteristics, volatile oil yield and chemical constituents in rosemary (Rosmarinus officinalis) plants was investigated. This investigation was followed a completely randomized block design and performed at the farm of Floriculture, Faculty Agriculture, Qena University, Qena Governorate, Egypt. The experiment consisted of nine treatments, including: 1) control, 2) 26 mM NaCl, 3) 26mM NaCl plus 1.5ml/L AE, 4) 26mM NaCl plus 3.0 ml/L AE, 5) 52mM NaCl, 6) 52mM NaCl plus 1.5ml/L AE, 7) 52mM NaCl plus 3.0 ml/L AE, 8) 1.5 ml/L AE, and 9) 3.0 ml/L AE. Rosemary plants subjected to saline water irrigation and sprayed with AE attained higher values of biometric traits such as plant height (cm), number of branches number, fresh weight of herb (g), dry weight of herb (g), leaf area (cm2), and total leaf area (cm2) than those irrigated by saline water without AE. Essential oil percentage and yield (ml/plant) also increased in plants irrigated with saline water and sprayed with AE. Spraying rosemary plants with either of the two tested concentrations of AE (1.5 or 3.0 ml/L) led to improve growth and productivity when compared to the other treatments, especially with the higher level. In addition, introducing AE, especially at 3.0ml/L to plants affected by salinity improved physiological characteristics like total chlorophylls, total carbohydrates, total phenols, and free proline than those subjected to saline water irrigation without AE. Results concluded that growth and productivity of rosemary plants can be progressed with acclimating them under conditions of salt stress by spraying algae extract at rate of 3.0 ml/L. This attempt helps rosemary producers to alleviate the harmful impacts of salinity in newly reclaimed sandy soils.