The Use of Seed Priming Treatments to Improve the Quality of Barley (Hordeum vulgare L.) for Malting

Grain barley (Hordeum vulgare L.) is the predominant raw material used to produce malt for industries such as brewing and the food industry. In Thailand, barley has been introduced to Thai farmers to improve farm income and reduce barley imports, but the seed quality of Thai-grown barley is often lower than required for profitable malt production, especially in the aspect of seed germination and vigor, and high pathogen contamination. Thus, this study was conducted to evaluate the effects of different seed priming methods on seed quality of Thai barley for malt production. Three experiments were conducted. The first experiment was hydro-priming: seeds were primed in deionized water for 6, 8, 10, 12, 14, or 16 hours. The second experiment was hydro-priming plus potassium nitrate treatment: seeds were primed in four different concentrations of KNO3 solution: 2.5, 5, 10, or 20 mg/ml for 6, 8, 10, and 12 hours. The third experiment was osmo-priming by PEG4000: seeds were primed in solutions of three different osmotic potentials: −0.50, −0.75, or −1.50 MPa for 10, 12, 14, or 16 hours. All seed priming methods accelerated barley germination and increased seed vigor. Primed barley seed germinated within 1 day. Barley seeds were primed with hydro-priming plus KNO3 at 5 mg/ml for 12 hours had significantly high seed germination and speed of germination. Hydro-priming plus KNO3 and osmo-priming by PEG4000 could speed up seed germination. We conclude that all three of these seed priming techniques could be effectively applied to improve barley seed quality in the Thai malt industry. However, further study is needed to evaluate the effects of seed priming methods on barley seed storability and other attributes of malt quality.