Allelopathic Effect of Different Organs Aqueous Extracts of Lambsquarters (Chenopodium album L.) and Common Cocklebur (Xantium strumarium L.) on Emergence, Growth and Development, Essential Oil Content and Yield of Summer Savory (Satureja hortensis L.)

Allelopathic effect of weeds is one of the important limiting factors that affects the growth and yield of medicinal plants. In this study, the effects of aqueous extracts of different organs of Lambsquarters (Chenopodium album L.) and Common cocklebur (Xantium strumarium L.) (shoot, root and whole plant) (2%W/V) were investigated on emergence percentage, growth and development and essential oil content and yield of summer savory (Satureja hortensis L.). A greenhouse experiment was carried out in randomized complete block design with five replications. Results showed that the aqueous extracts of lambsquarters shoot and common cocklebur whole plant reduced emergence percentage of summer savory. Aqueous extract of different organs of both weeds had significant effect on morphological traits as well. In this regard, results indicated that the aqueous extract reduced summer savory bush height, number of leaves per plant and dry weight of shoot and root. Despite of increase in essential oil content of summer savory, essential oil yield of summer savory was reduced by different organs aqueous extracts of both weeds.