Abstract

In order to study the effect of planting date and plant density on morphological traits, yield and water use efficiency (WUE) of Plantago ovata, an experiment was conducted as a split-plot based on a Randomized Complete Block Design with three replications at experimental field of Islamic Azad University, Birjand Branch, Birjand, Iran in 2008. The main plot was planting dates (April 19, May 9 and May 30) and the sub-plot was plant densities (16.6, 22.2 and 33.3 plants/m²). Means comparison indicated that retarding the planting from April 19 to May 30 decreased significantly plant height, spike length, leaf number/plant, husk, leaf and grain yield, and WUE for grain production by 24.5, 29.9, 18.2, 65.4, 60.2, 60.2 and 46.9%, respectively. As the results showed, with the increase in plant density from 16.6 to 33.3 plants/m², plant height, grain yield and water use efficiency were increased significantly by 7.8, 82.8 and 82.1%, respectively, but leaf number per plant, spike length and tiller number per plant were decreased by 24.8, 5.9 and 28.9%, respectively. The highest husk and leaf yield, and WUE for biomass production were obtained at the density of 33.3 plants/m² which was higher than those at the density of 16.6 plants/m² by 2.11, 2.10 and 2.06 times, respectively. In total, according to the results, the planting date of April 19 with the density of 33.3 plants/m² is recommended to realize maximum yield and water use efficiency inPlantago ovata cultivation in Birjand region, Iran.

Key words: Plantago ovata, planting date, plant density, yield, water use efficiency.