Pepper

Capsicum annuum

1. Identification and origin

The pepper (Capsicum annuum L.) is an annual vegetable species of the Solanaceae family, native to Central America and Mexico. The crop spread globally after the European expansion, and is currently one of the most widely cultivated vegetables both in greenhouses and in the open field. In Portugal, it is widely grown in the Ribatejo, Oeste, Algarve and coastal greenhouses.

2. Economic importance

The pepper is a crop of high commercial importance, with a strong presence in the fresh market and in industry (preserves, dehydrated products, sauces). In greenhouses, it allows continuous production and high productivity. The diversity of colours, shapes and sizes increases the commercial value and market segmentation.

3. Botanical characterisation

An annual plant, of erect habit, 50–120 cm tall. The leaves are simple, ovate and glabrous. The flowers are white, solitary, with a star-shaped corolla. The fruits are hollow berries, of great variability in shape, colour and wall thickness, and may be sweet or hot. The root system is deep, but sensitive to waterlogging.

4. Soil and climate requirements

The pepper is a warm-climate crop, with ideal temperatures between 22–28 °C. It is sensitive to cold, especially below 12 °C. It prefers well-drained soils, of loamy to sandy-loam texture, rich in organic matter, with a pH between 6.0 and 7.0. It requires regular irrigation and balanced fertilisation, with emphasis on nitrogen, potassium, calcium and magnesium. High relative humidity favours fungal diseases.

5. Main pests

• Whitefly (Bemisia tabaci, Trialeurodes vaporariorum): sap sucking and transmission of viral diseases
• Thrips (Frankliniella occidentalis, Thrips tabaci): silvering, lesions on the fruit and transmission of viral diseases
• Aphids (Aphididae): leaf curling and virus transmission
• Mites (Tetranychus urticae): leaf chlorosis and necrosis
• Fungus gnat (Bradysia spp.): root damage in seedlings
• Nematodes (Meloidogyne spp.): root galls and vegetative decline
• Noctuids (Spodoptera spp.): leaf perforations and damage to the fruit

6. Main diseases

• Powdery mildew (Leveillula taurica): chlorotic spots and mycelium on the lower surface
• Downy mildew (Peronospora tabacina): angular spots and necrosis
• Root rots (Phytophthora capsici, Pythium spp.): wilting and death of plants
• Anthracnose (Colletotrichum spp.): sunken lesions on the fruit
• Cucumber mosaic virus (CMV): mosaics and deformations
• Tobacco mosaic virus (TMV): mosaics and necrosis
• Tomato spotted wilt virus (TSWV): necrosis, rings and decline

7. General crop management

Pepper management includes the use of cultivars resistant to viral diseases and soil-borne diseases, vertical training in greenhouses, adequate ventilation and controlled irrigation. Fertilisation should be balanced, avoiding excess nitrogen that favours excessive vegetative growth and susceptibility to diseases. Control of whitefly, thrips and mites is essential to avoid significant losses. Harvesting is carried out when the fruits reach the desired size and colour, depending on the market.

Bibliographic references

• EPPO Global Database – Capsicum annuum
• CABI – Crop Protection Compendium – Capsicum annuum
• Bosland, P. W., et al. (2012). Peppers: Vegetable and Spice Capsicums. CABI.
• FAO (2021). Protected Cultivation of Vegetables.
• López‑Gálvez, G., et al. (2020). Pepper production in greenhouses. Acta Horticulturae.
• Jones, J. B., et al. (2014). Compendium of Pepper Diseases and Pests. APS Press.