Effects of vermicompost and humic acid on morphological traits, yield, essential oil content and component in organic farming of Ajwan (Trachyspermum ammi L.)

Nowadays, using organic inputs instead of chemical fertilizers is the most important point for achieving soil productivity and suitable plant nutrition in organic farming. The application of these inputs not only protects the environmental health, but also improves the qualitative characteristics of medicinal plants. The purpose of this research was to investigate the effects of vermicompost and humic acidon morphological traits, yield, essential, oil content and component of Ajowan (Trachyspermum ammi L.). Thus, a field experiment was conducted in the Agriculture Research Station of Kurdistan University in 2013. The treatments consisted of three level of vermicompost (0, 5 and 10 t.ha-1) and three levels of humic acid (0, 0.5 and 1 percent). The study was conducted in a randomized complete blocks design with factorial arrangement and three replications. The results showed that the highest plant height and number of umbels/plant were obtained at the third level of vermicompost. The third level of humic acid caused the highest values of plant height and number of umbels/plant, as well. The highest number of umbel /plant, seed and biological yield and essential oil percentage were obtained with applying the third level of vermicompost and humic acid. Hence, it seems that organic fertilizers such as vermicompost and humic acid could be applied as a proper alternative to improve the qualitative and quantitative yield of Ajowan.