Influence of drought stress and nitrogen on dry matter partitioning of Isabgul (Plantago ovate Forsk)

In this study, the effects of drought and nitrogen were analyzed on morphological traits and dry matter allocation of Isabgul (Plantago ovata) at Vali-e-Asr University of Rafsanjan in 2010. The research was conducted using factorial experiment based on RCD design with 3 replications. The factors included nitrogen (0, 60, 120 and 180 mg N.Kg-1 soil) and soil moisture (100, 80, 60, 40 % FC). Results indicated that drought, nitrogen and their interaction significantly affected seed yield and total dry weight. The highest seed yield (1.72 g.plant-1) was obtained at 120 mg N.Kg-1 soil which was 77% higher than that in control. In 80% FC treatment, using 120 mg N.Kg-1 soil caused 93% increase in total dry weight, compared to control. In addition, with increasing drought stress, dry matter partitioning benefited the root and root mass ratio (RMR) increased significantly. However, no significant changes were recorded for shoot mass ratio (SMR) and grain mass ratio (GMR). Also, with increasing nitrogen fertilizer, more dry matter was transferred to the leaves and less dry matter was transferred to the seed.