Effect of plant density on growth, yield and essential oil characteristics of Iranian Tarragon (Artemisia dracunculus L.) landraces

Abstract

An experiment was conducted during two years of 2014 and 2015 to determine the optimum plant density of different Tarragon landraces in Iran. A factorial experiment based on a completely randomized block design with three replications was used. Factors consisted of three Tarragon landraces including Isfahan, Hamedan and Varamin and four plant densities of 6.6, 8, 10 and 13.3 Pl.m−2. Morphological, growth, yield related and essential oil traits are studied. Results showed that Isfahan population is a population with late establishment in first year but with higher branching property and leaves to stems ratio. The highest essential oil percentage belonged to Hamedan and Varamin populations but it was no significant difference in essential oil yield between populations. Increasing the plant density decreased leaf size, number of branches and shoot and leaves dry weights per plant in both years of study. The highest shoot and leaves dry weights per unit area in second year was obtained in Isfahan population but it was no significant difference of essential oil yield between populations. The highest shoot dry weight and leaves dry weight per unit area was achieved in plant density of 10 pl.m−2 but the highest essential oil yield obtained in plant density of 8 pl.m−2. The highest shoot and leaves dry weights per unit area and essential oil yield was achieved by Isfahan population in plant density of 8 pl.m−2.