Potato

Solanum tuberosum

1. Identification and origin

The potato (Solanum tuberosum L.) is a herbaceous species of the Solanaceae family, native to the Andean region, especially present-day Peru and Bolivia. Domestication occurred around 7,000–10,000 years ago, from wild species of the S. brevicaule complex. The crop was introduced into Europe in the 16th century and spread rapidly due to its high nutritional value and adaptability to different soil and climate conditions.

2. Economic importance

The potato is currently the fourth most important food crop in the world, after maize, wheat and rice. It is used for fresh consumption, industry (chips, flakes, starch), animal feed and seed-tuber production. In Portugal, it is grown in several regions, notably the northern and central coast, the Azores and some areas of the Alentejo. Its economic value results from high productivity, culinary versatility and importance to food security.

3. Botanical characterization

A perennial herbaceous plant grown as an annual, 40–100 cm tall. It has a branched aerial stem and an underground rhizome that gives rise to stolons, on which the tubers form. The leaves are compound, with oval leaflets. The flowers range from white to violet, depending on the cultivar. The tubers show great variability in shape, skin colour and flesh. The Andigenum and Chilotanum groups represent the main genetic pools cultivated globally.

4. Soil and climate requirements

The potato prefers cool temperate climates, with optimum temperatures of 15–20 °C. It is sensitive to frost and to temperatures above 30 °C, which reduce tuberization. It requires loose, well-drained soils, rich in organic matter and with a pH between 5.0 and 6.5. Regular water availability is essential, especially during tuber formation and bulking.

5. Main pests

• Potato tuber moth (Phthorimaea operculella): galleries in leaves and tubers.
• Colorado potato beetle (Leptinotarsa decemlineata): severe defoliation.
• Nematodes (Globodera spp., Pratylenchus spp.): root damage and yield losses.
• Aphids (Aphididae): vectors of viruses.
• Weevils and storage pests: post-harvest deterioration.

6. Main diseases

• Late blight (Phytophthora infestans): the most destructive disease, causing leaf necrosis and tuber rot.
• Early blight (Alternaria solani): concentric spots on the leaves.
• Potato virus Y (PVY) and potato leafroll virus (PLRV): reduced vigour and productivity.
• Common scab (Streptomyces scabies): corky lesions on the tubers.
• Rots caused by Fusarium spp. and Pectobacterium spp.: losses in storage.

7. General crop management

Management includes the use of certified seed tubers, crop rotation to reduce pest and disease pressure, balanced fertilization and regular irrigation. Earthing up is essential to protect the tubers from light and prevent the development of solanine. Preventive control of late blight is critical in humid regions. Harvesting should be carried out when the plant reaches physiological maturity and the tubers have a firm skin.

Bibliographic references

• EPPO Global Database – Solanum tuberosum.
• CABI – Crop Compendium – Solanum tuberosum.
• FAO (2021). Solanum tuberosum – A Promising Crop for Starvation Problem. IntechOpen.
• Hawkes, J. G. (1990). The Potato: Evolution, Biodiversity and Genetic Resources. Belhaven Press.
• Vreugdenhil, D. et al. (Eds.) (2007). Potato Biology and Biotechnology: Advances and Perspectives. Elsevier.