Evaluation of grain qualitative traits of Isabgol (Plantago ovata Forsk.) under limited irrigation regimes and different fertilizing treatments

In order to study the effect of fertilizing treatments and limited irrigation regimes on grain qualitative traits and mucilage production of Isabgol (Plantago ovata Forsk.)، a field experiment was conducted at Experimental Farm of College of Agronomy and Animal Sciences، University of Tehran. The experimental design was a split plot based on a randomized complete block design with three replications. In this research، four irrigation regimes including full irrigation، light limited irrigation، moderate limited irrigation and severe limited irrigation، were assigned to the main plots and five fertilizing treatments including control (without fertilizer)، chemical fertilizer، combined use of chemical fertilizer and Barvar Phosphate Biofertilizer، cattle manure and combined use of chemical fertilizer and cattle manure، were assigned to the sub plots. Results showed that irrigation regimes had significant effect (p ≤ 0. 05) on all measured traits. Mucilage and grain yields decreased with decrement in irrigation frequency from full to severe limited irrigation but mucilage percentage and grain swelling factor increased; therefore، the highest mucilage and grain yield were obtained in full irrigation regime. The highest mucilage percentage and grain swelling factor were obtained in severe limited irrigation. Results also showed that fertilizing treatments had significant effect (p ≤ 0. 05) on all measured traits. The highest mucilage yield (252. 58 kg/ha) was obtained in combined use of chemical fertilizer and cattle manure treatment under full irrigation regime. Mucilage percentage and grain swelling factor were significantly higher (p ≤ 0. 05) in cattle manure treatment.