Effect of plant density on growth indices and yield of henna (Lowsonia inermis L.) ecotypes in Shahdad region of Iran

To investigate the effect of plant density on growth indices and photosynthesis of three henna (Lowsonia inermis L.) ecotypes a factorial experiment using randomized complete block design with three replications was carried out in the Shahdad region in Kerman province of Iran in 2015-2016. Three henna ecotypes (Bam, Shahdad and Roodbar) and four plant densities (100, 50, 33 and 25 plant.m-2 equivalent to on row spacing of 5, 10, 15 and 20 cm, respectively) were evaluated as the first and second experimenatl factors, respectively. Growth indices, net photosynthesis, transpiration rate and stomatal conductance were measured and analyzed. The results showed that ecotypes were significantly different for all measured traits except leaf area index (LAI), leaf area ratio (LAR) and leaf area duration (LAD). The highest averages of the measured traits belonged to Shahdad ecotype. A significant difference was observed between the levels of plant densities for all measured traits except for specific leaf area (SLA). The ecotype and plant density interaction had significant effect on leaf area duration (LAD), biomass duration (BMD) and transpiration rate. Consequently, the highest leaf dry yield (economically valuable part of the plant) was obtained from the Shahdad (508.2 g.m-2) and Roodbar (506.4 g.m-2) ecotypes and plant density of 100 plant.m-2 (738.6 g.m-2). It can be concluded that 100 plant.m-2 is the most suitable plant density for henna in the first year of planting.