Evaluation of the compatibility of Salvia sahendica L. plant with water stress and determining the appropriate irrigation interval for use in landscape

The grass is one of the plants that is used widely in the landscape of industrial centers. This plant has a high water requirement. So, because of low precipitations in recent years, from some medicinal plants are applied in landscape. Because, these plants not only resist to adverse environmental conditions, but also have low water requirement, nutrition and low maintenance cost in comparison to grass. However, in each region their adaptation and yield depends on various factors such as climatic conditions, physical and chemical conditions of the soil, water quality, irrigation intervals and type of plant. For this reason, the present study was designed to evaluate the compatibility of Salvia sahendica plant to water stress and determining the appropriate irrigation regime to apply as landscapes in industrial centers.

This experiment was conducted at the research farm of Isfahan Mobarakeh Steel Company. After field preparation, the research treatments including five irrigation interval (2 (control), 4, 8, 12 and 16 days) as the main factor and two plant including grass and Salvia sahendica as subsidary factors was carried out in a Split plot design with randomized complete block design with 2 × 2 meters plotted in 3 replications in 1395. After the establishment of plants, the water stress was applied by irrigation intervals. At the end of the summer, the plants (leaf, root and whole plant) were harvested and plant growth factors were measured in three replications. The means comparison conducted by LSD method using MSTAT-C software.

The results of analysis of variance showed that the effects of irrigation interval, species and their interaction were statistically significant at 1% on all morphological and physiological traits. Based on the results of the means comparison, by increasing the irrigation interval from 2 to 4, 8 and 16 days, a significant reduction in the studied traits were observed in the grass (pr<0.05). while, the lowest percentage of viability (5%), surface coverage (5%), visual scoring (10%), leaf area index (4%), relative water content of leaves (9%) and chlorophyll index (3%) was observed in the 16-day interval as compared with control plant, but the reduction of these traits in the Salvia sahendica was not significant to 16 days (pr>0.05). In this plant, the lowest records of named traits were (60%), (67%), (66%), (80%), (68%) and (59%) respectively in 16 days interval. In the grass, proline content, electrolyte leakage, the ratio of root to shoot dry weight and the root highest length were significantly increased by increasing irrigation intervals to more than 2 days (pr <0.05). These traits increased 4.7, 4.2, 2.3 and 2.6 times respectively in the 16-days irrigation interval in this plant. In Salvia sahendica, this parameters was not afftected to 16-days interval. In 16-days interval, these traits increased by 1.2, 2, 1.7 and 1.9 times respectively.

By considering that non-significant decreases were observed (pr>0.05) in the studied parameters of Salvia sahendica up to 12-days interval in comparison with control, it can be concluded that an optimal irrigation regime of this plant in order to use in the landscape is irrigation interval of 12-days. It saves water resources in comparison with grass. According to results, the use of Salvia sahendica is recommended for use as landscape and alternative of grass in the studied area and in other similar areas at confidence level of 95%.