Barley

Hordeum vulgare

1. Identification and origin

Barley (Hordeum vulgare L.) is an annual grass of the Poaceae family, native to the region of the Fertile Crescent. It is one of the first cereal species to be domesticated and continues to be widely cultivated in temperate regions, being fundamental for animal feed, the brewing industry and the production of flours.

2. Economic importance

Barley is used in the production of malt for beer and distilled beverages, in animal feed (grain and forage) and, to a lesser extent, in human food. It is valued for its hardiness, short cycle and good adaptation to poor soils and cold climates, being a strategic crop in rainfed farming systems.

3. Botanical characterisation

Annual plant of erect habit, with hollow stems and linear leaves. The inflorescence is a spike composed of three spikelets per node, which may be two-rowed or six-rowed, according to the varietal type. The grains are elongated, with or without awns, depending on the cultivar. The root system is relatively deep, conferring good tolerance to drought.

4. Soil and climate requirements

It prefers cool temperate climates, being more tolerant to cold than wheat. It develops well on light to medium, well-drained soils, with a pH between 6.0 and 7.5. It tolerates soils of lower fertility, but it is sensitive to waterlogging. Spring barley requires moderate temperatures during grain filling to ensure malting quality.

5. Main pests

• Aphids (Aphididae): sap-sucking and transmission of viral diseases.
• Hessian fly (Mayetiola destructor): damage to stems and reduced productivity.
• Caterpillars (Lepidoptera): partial defoliation.
• Nematodes (Heterodera avenae): reduction of vigour and root development.
• Grain weevil (Sitophilus granarius): damage in storage.

6. Main diseases

• Powdery mildew (Blumeria graminis): white mycelium on young leaves.
• Net blotch (Pyrenophora teres): leaf lesions and reduction of yield.
• Scald (Rhynchosporium secalis): leaf spots and loss of photosynthetic area.
• Brown rust (Puccinia hordei): leaf pustules and productive decline.
• Fusarium head blight (Fusarium spp.): contamination by mycotoxins.

7. General crop management

Management includes the choice of varieties adapted to the purpose (malting or forage), sowing at the appropriate time, balanced density and moderate fertilisation, especially with nitrogen. Crop rotation reduces the pressure of leaf and soil diseases. Monitoring of aphids and powdery mildew is essential in early stages. For malting barley, it is fundamental to avoid an excess of nitrogen and to ensure harvest at the optimum moisture point.

Bibliographic references

• EPPO Global Database – Hordeum vulgare.
• CABI Crop Compendium – Hordeum vulgare.
• Ullrich, S. E. (2011). Barley: Production, Improvement, and Uses. Wiley‑Blackwell.
• Briggs, D. E. (1998). Malts and Malting. Springer.
• Newton, A. C. et al. (2011). Climate change and barley production. Journal of the Science of Food and Agriculture.