عنوان مقاله [English]
Drought stress is the main limiting factor of crop growth and yield in arid and semi-arid regions. Hyssop (Hyssopus officinalis L.) is one of the most important medicinal plants with various medical applications. To study the effect of deficit irrigation on hyssop morphological traits including plant height, leaf, shoot and stem weight, root volume and density and root to shootratio, an experiment was carried out based on randomized completely design in four replications at Research Greenhouse of Agricultural College of Shirvan. The irrigation deficit levels were 100, 75, 50 and 25% of field capacity as control, mild, medium and severe stress, respectively. Increasing of deficit irrigation from medium to severe stress declined plant height, leaf, stem and shoot weight, root volume and weight. However, root dry to shoot weight ratio increased with increasing deficit irrigation level. On the whole, the experiment results showed relative tolerance of hyssop to mild stress. Therefore, hyssop planting in arid and semi-arid with mild stress is recommending.