Do Fertilizers and Irrigation Disruption Change Some Physiological Traits of Safflower?

Abstract

To investigate the effects of nanofertilizers and biofertilizers on the morpho-physiological and biochemical traits of safflower under full irrigation and water deficit stress, this study was carried out as a split-plot experiment based on a Randomized Complete Block Design with three replications at Urmia University in 2015. The main plot was full irrigation (control) and irrigation disruption at heading, flowering, and grain filling stages. Fertilizers, including control (without fertilizer), biofertilizer, water spray, foliar application of nanofertilizers, chemical fertilizers, and combined application of fertilizers, were assigned to the subplot. Plants under full irrigation and combined fertilizers had maximum height and chlorophyll a, whereas the lowest ones were obtained in irrigation disruption at the heading stage and control treatments. The maximum oil content (28.41%) was detected in irrigation disruption at the grain filling stage and nanofertilizer treatment, the lowest (21.96%) was obtained at irrigation disruption at the flowering stage and water spray treatment. The highest proline (397.21 µg g−1 fresh leaf) was found in irrigation disruption at the grain filling stage and water spray treatment, and the lowest (154.68 µg g−1 fresh leaf) was obtained at full irrigation and water spray treatment. Irrigation disruption at the heading stage and control treatments decreased carbohydrate content of fresh leaves by 86.54% compared to full irrigation and the combined fertilizers treatment. Irrigation disruption increases saturated fatty acids (palmitic and stearic acid) and decreases vitamin E and linoleic acid. The combined application of fertilizers significantly increased safflower oil quality. Overall, concerning the obtained highest oil percentage (28.41%), irrigation disruption during grain filling reduced water consumption and application of combined fertilizer via improving oil quality, so it is recommended to farmers.