Evaluation of Morphological Traits, Yield Components and Essential Oil Content of Dragon's Head (Lallemantia iberica Fischer & C.A. Meyer) under Weed Interference Periods

The effect of different interference and weed control period on morphological traits, yield components, oil and mucilage contents of Dragon’s head, studied by field experimental based on randomized complete block design with three replicates and 15 treatments at the Agricultural Research Station, University of Tabriz. The treatments were six periods of weed interference, six periods of weed control, weed free and weed infected during the growing season and, pure weed (without crop). The results indicated that weed dry weight significantly increased with increasing duration of infection and decreasing weed free period. Number of leaves per plant, plant height, number of capsules and seeds, 1000-seed weight, biological and grain yield reduced with increasing weed interference period. Among the yield components, number of seeds per plants decreased by 46.8% related to weed free control and so it was the most sensitive component. The effect of treatments on percentage and yield of essential oil and seed mucilage was not significant. Weed infested control with 1200 kg.ha-1 and weed free control with 2289 kg.ha-1 had the lowest and the highest grain yield, respectively. Evaluation of Dragon’s head performance under weedy conditions with 1200 kg.ha-1 grain yield indicated the high competitive potential of medicinal plant of Dragon’s head in front of natural weeds of field. This capability embosses success of this plant in competition with weeds accompanied by acceptable level of grain yield.