Determining the critical period for weed control in summer savory (Satureja hortensis L.): A comparative study across two locations

İngilizce (OpenAlex)

Summer savory (Satureja hortensis L.) is an important medicinal and aromatic plant valued for its essential oil content and its use in the food, pharmaceutical and cosmetics industries. Weed competition is one of the major challenges in the cultivation of this plant. The aim of this study was to determine the critical period for weed control (CPWC) and to evaluate the impact of weed competition on yield and essential oil composition in two different locations (A and B). The dominant weed species were Tribulus terrestris, Amaranthus retroflexus, Xanthium strumarium, Portulaca oleracea and Sorghum halepense. The highest values for yield parameters including essential oil yield, fresh and dry biomass, dry leaf yield and plant height were recorded in the weed-free plots, while the lowest values were observed in the continuously weedy plots. Weed interference caused significant yield losses ranging from 51.0% to 78.7% depending on the location. Based on a 5% acceptable yield loss threshold, CPWC ranged from 7 days after sowing to harvest at Location A (106-1237 growing degree days, GDD), and from 10 to 37 days after sowing at Location B (160-759 GDD). Essential oil yield was highest in weed-free plots (41.19-60.27 L ha-1) and lowest in continuously weedy plots (14.01-29.67 L ha-1). The major constituents of the essential oil were carvacrol (32.3-61.5%) and γ-terpinene (16.4-28.9%), both of which were affected by weed competition. These results demonstrate the importance of early weed control due to the low competitive ability of summer savory to improve both yield and essential oil quality in S. hortensis production.