Effect of Irrigation Intervals and Silicon Spraying on Barley Plants (Hordeum vulgare L.): Implications for Grain Quality and Malting Characteristics

• Zeena A. Otaife¹*, Karim M. Bhiah²

  Author

A greenhouse experiment was conducted at the College of Agriculture, University of Kufa, during the 2025-2026 agricultural season to study the effects of four silicon concentrations and three irrigation durations on the vegetative growth characteristics, nutrient uptake, and grain quality of barley plants (Hordeum vulgare L.) with implications for food processing and malting applications. A factorial experiment was carried out using a randomized complete block design with two factors. The first factor was silicon concentration (0, 1, 1.5, and 2 ml L⁻¹), and the second factor was irrigation intervals (every 2, 4, and 6 days). Results indicated that silicon spraying significantly increased plant height (68.22 cm), chlorophyll content (16.89 SPAD), leaf nitrogen (0.970%), leaf phosphorus (0.542%), leaf potassium (2.498%), grain nitrogen (0.89%) grain phosphorus (0.546%), grain potassium (0.180%), grain silicon (0.426%), grain calcium (0.240%), leaf protein (6.06%), grain protein (5.5625%) and grain weight per pot (34.73 g). Irrigation intervals significantly affected plant height (62.86 cm), chlorophyll content (15.92 SPAD), leaf nitrogen (0.806%), leaf phosphorus (0.438%), leaf potassium (2.442%), grain nitrogen (0.74%), grain phosphorus (0.512%), grain potassium (0.126%), grain silicon (0.233%), grain calcium (0.167%), leaf protein (5.038%), grain protein (4.514%), and grain weight per pot (31.63 g). The interaction between silicon spraying and irrigation intervals produced the highest values for plant height (75.20 cm), chlorophyll (18.33 SPAD), shoot dry weight (41.42 g), number of active branches (13.33), leaf nitrogen (0.95%), leaf phosphorus (0.740%), leaf potassium (2.520%), grain nitrogen (0.99%), grain phosphorus (0.795%), grain potassium (0.257%), grain silicon (0.651%), grain calcium (0.277%), leaf protein (6.47%), grain protein (5.54%), and grain weight per pot (43.63 g). From a food industry perspective, the enhanced grain protein content (up to 5.54%) and improved mineral composition (nitrogen, phosphorus, potassium, silicon, calcium) are critical quality parameters for malting, brewing, and animal feed applications. The increased silicon accumulation in grains (up to 0.651%) may contribute to improved grain hardness and processing characteristics. This study demonstrates that optimized irrigation and silicon fertilization can significantly enhance barley grain quality attributes relevant to food processing, malting, and brewing industries.

• pdf