The grass species lemongrass, palmarosa, and citronella/nardus grass are one of the aromatic and medicinal plants which know days Wondo genet Agriculture center is working on their essential oil yield increment and releasing different varieties. The essential oils were extracted using hydro distillation methods. This study investigated the analysis of physical characteristics of lemongrass varieties, palmarosa, and citronella grass essential oils. From the released three lemongrass varieties WG-Lomisar-Java has the highest oil content (1.25 %± 0.02) and the other two varieties namely Lomisar-I and WG-lomisar-UA (upper awash) have the same oil content (1.2%± 0.02). WG-lomisar-UA (upper awash) has the largest relative density/specific gravity (0.9015± 0.0002) and WG-Lomisar-Java has the smallest value (0.9007± 0.0002). In the case of the refractive index, Lomisar-I has a large value (1.4890± 0.0002) and WG-Lomisar-Java has a small value (1.4870± 0.0002). The oil content of palmarosa was 1.2%± 0.03, the specific gravity was 0.8815± 0.0002 and the refractive index was 1.4720± 0.0002, whereas Citronella grass contains 1.3%± 0.01 oil content, 0.9108± 0.0002 specific gravity, and 1.4800± 0.0002 refractive indexes.

Basil (Ocimumbasilicum L.) is an herbaceous annual aromatic herb that belongs to the Lamiaceae family. This study aimed to analyze the essential oil content and physicochemical properties of basil varieties stored under different drying methods and dried on different drying days. The fresh leaf of basil varieties was collected from the Wondo Genet Agriculture research center experimental field and subjected to open sun and shade drying methods and four drying days (0,5, 10, and 15). The sample was subjected to oven and hydrodistillation methods on each four particular drying days. The obtained essential oils were analyzed for physical properties (specific gravity and refractive index) and chemical composition using GC-MSD. As shown in the result of all-cause drying methods and drying days significantly affect the essential oil content and physicochemical properties of Basil Variety. In the case of Variety, Basil 02 has a high essential oil content than Basil 05 in the chemical composition, and different chemical compositions exist in both. In the case of drying methods, the sample dried under the shade is higher than in the open sun in essential oil content and physicochemical properties. In the case of different drying days, as the drying days increase, the essential oil content is significantly affected. The essential oil content and physicochemical properties of essential oil decrease as drying days increase for both basil varieties. Drying affects the chemical composition of the two variables, which means, as in the cause of open sun drying, affects the chemical composition more than shade drying as the drying days increase, and the chemical composition decrease. Therefore, this study provides evidence that drying herbs on different drying days and under drying conditions affect the essential oil content and physicochemical properties of essential oil.

The genus Rue (Ruta chalepensis) is an aromatic medicinal plant used in the folk as an herbal remedy medicine for the treatment of a variety of disorders in Ethiopia. Information about the effects of drying methods and storage days on essential oil physical properties is limited. The fresh leaf of rue was collected from the Wondo Genet Agriculture research center and was subjected to sun and shade drying methods and four storage days (0,5,10, and 15) days for each day's moisture content and essential oil extraction using hydro distillation. The obtained essential oils were analyzed for physical properties (specific gravity and refractive index). The highest value of moisture content in percent was recorded at 0-day storage days with the value of 73.533 and the lowest one was recorded at 15-day sundry with the value of 8.400. The highest and lowest value of essential oil content in volume by weight in percent was 0.673 and 0.174 at 0 day and 10-day sun, respectively. The highest and lowest value of essential oil content weight by weight in percent was 0.996 and 0.287 at 0 day and 15-day sun, respectively. The results showed that the rue dried under shade had a higher level of moisture content, essential oil content, volume by weight and weight by weight, specific gravity, and refractive index compared to the rue leaf dried under sun-drying methods. In the case of storage days in all parameters except refractive index and specific gravity, the rue fresh leaf (0 days) was higher in moisture content and essential oil contents compared to others storage days. This study provides evidence that drying herbs for different storage days and different drying methods affect the essential oil content and physical properties of essential oil.