Treatments for the Optimization of Salsola turcomanica (Litv) Seed Germination and the Effects of Different Drought and Salinity Levels

Salsola turcomanica (Litv) is a widespread wild plant species in Middle Eastern arid and semi-arid areas and is a relatively palatable halophyte species that has low establishment rate in the field. In winter 2017, in order to optimize the germination indices, its seeds were treated by scarification, stratification, scarification after stratification, gibberellic acid, potassium nitrate and hot water. Then, in separate trials, the effects of six levels of drought stress (0, -2, -4, -6, -8, -10 Bar) and salinity (0, 5, 10, 15, 20, and 25 ds/m) were assessed under laboratory conditions as well as the effect of four sowing depths (0, 0.5, 1, and 1.5 cm) investigated on seedling emergence under greenhouse conditions. All four experiments were carried out using completely randomized designs with four replications. A significant decrease was observed in the seed germination indices by increasing drought and salinity stress levels (p<0.05). This species had moderate to low germination percent under -2 bar drought stress and 15 ds/m salinity. Based on the obtained result, the scarification was the best treatment of seed germination, so the seeds of S. turcomanica were scarificated and sown (100 kg/ha) in the field at the end of autumn 2018. According to the results, the highest seed emergence was observed at the shallow depth sowing and resulted in 28.7% vegetation cover and 176.44 (g/m2) dry matter production at the end of growing season. So, it was concluded that for dry land farming system, cultivation of this species in winter rangelands can reduce wind erosion during its growth period in summer and provide a considerable quantity of forage. Based on the results of this research, cultivation of this species can be recommended to rangeland improvement or ley-farming projects.