Assimilate and nitrogen remobilization of six-rowed and two-rowed winter barley under drought stress at different nitrogen fertilization

ABSTRACT

Field experiments were conducted to investigate the effects of irrigation regimes and N levels on assimilate remobilization of two barley cultivars (Yousef_six-rowed and Nimrouz_two-rowed) in 2011 and 2012. There were three levels of water regimes (full irrigation (I₁₀₀), 75% and 50% of I₁₀₀: I₇₅ and I₅₀, respectively) in 2011. Rain-fed treatment (I₀) was included in 2012. Three N levels (0, 60, and 120 kg ha⁻¹) were used. Grain yield and assimilate remobilization decreased by severe water stress (I₀), however, the reduction of them were intensified by N fertilizer application. The N remobilization was negatively affected by N fertilization and water stress. The two-rowed showed higher N remobilization (10.7%) and contribution of N remobilized to N content of grain (5.8%) than the six-rowed. The two-rowed cultivar showed significantly higher assimilate remobilization and grain yield than the six-rowed under I₅₀ (26.3% and 6.5%, respectively) and I₀ (48.7% and 17.1%, respectively), while the six-rowed had similar or higher performances in terms of these traits under I₁₀₀ and I₇₅. This study showed that optimizing irrigation and N rates (decrease N level with increasing water stress) and selection of the suitable cultivars (Nimrouz_two-rowed) might increase assimilate remobilization and consequently grain yield under drought stress conditions.

KEYWORDS:

• Six-rowed barley
• two-rowed barley
• assimilate remobilization

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Shiraz University.