Study of the Essential Oil, Morphological Parameters, and Growth–stage-Specific Crop Coefficients of Summer Savory (Satureja hortensis L.)

Abstract

This research was conducted to study of the essential oil content, some morphological parameters, crop evapotranspiration (ET_c) and crop coefficient (K_c) of Summer Savory (<em>Satureja hortensis </em>L<em>.</em>) in the west of Iran (Khorramabad region) in 2017. Weighing Lysimeters (25 cm diameter and 30 cm height) were used to measure important morphological parameters, the evapotranspiration of grass (ET₀) and Summer Savory (ET_c.) for the first time (Three lysimeters for each plant that was considered as replication). Irrigation was performed by the weighing method. The results showed that the essential oil content was 1.083%(w/w), and the average of plant height, stem diameters, root length, root diameter, number of leaf per plant, leaf and flower dry weight, stem dry weight were 47cm, 3.13mm, 14.5cm, 2.26mm, 630.7, 0.866 g/plant, 0.890 g/plant, respectively. Crop coefficient (K_c) can be used in predicting exact water requirement of crops. The result indicated that seasonal ET₀and ETcwere884.26 mm and 776.64mm. The best polynomial curve for K_c values as a function of the days after planting (DAP) was a third polynomial (). Likewise, the growth-stage-specific crop coefficient, based on FAO approach (FAO-56 K_c) was 0.45, 0.78and 1.3. Development of the regional K_c helps in irrigation management and water resources protection.