Pistachio

Pistacia vera

1. Identification and origin

The pistachio (Pistacia vera L.) is a tree species of the Anacardiaceae family, native to Central Asia and the Middle East, especially Iran, Turkmenistan and Afghanistan. The crop has spread to the Mediterranean basin, the United States and Australia. In Portugal, it is expanding, mainly in inland regions with a hot, dry climate.

2. Economic importance

The pistachio is a high-value nut with strong international demand. The crop offers good profitability under hot, dry climate conditions, and is valued for its resistance to salinity and the longevity of the orchards. The fruit is consumed raw, roasted or used in the food industry (pastry, ice cream, confectionery).

3. Botanical description

A deciduous tree of medium size, reaching 4–8 m in height, with a rounded crown. The leaves are compound, paripinnate, with thick leaflets. The species is dioecious, requiring the presence of male and female plants for fruiting. The inflorescences are terminal panicles. The fruit is a drupe with a hard shell and an edible seed (pistachio). The root system is deep, conferring good tolerance to drought.

4. Soil and climate requirements

The pistachio adapts to hot, dry climates, with long summers and high temperatures. It requires cold winters to break dormancy. It prefers well-drained soils, of loamy to sandy-loam texture, tolerating salinity and active limestone. It is sensitive to waterlogging and heavy soils. Supplementary irrigation increases productivity and fruit size.

5. Main pests

• Fruit fly (Ceratitis capitata): oviposition and rots
• Scale insects (Aonidiella aurantii, Saissetia oleae): sap sucking and sooty mould
• Aphids (Aphididae): leaf curling and transmission of viruses
• Mites (Tetranychus spp.): chloroses and leaf necroses
• Carob moth (Ectomyelois ceratoniae): borings and premature drop
• Nematodes (Meloidogyne spp.): root galls and vegetative decline

6. Main diseases

• Alternaria blight (Alternaria alternata): leaf spots and necroses on the fruits
• Botryosphaeria blight (Botryosphaeria dothidea): cankers and branch death
• Verticillium wilt (Verticillium dahliae): wilting and progressive decline
• Root rots (Phytophthora spp.): wilting and sudden death in waterlogged soils
• Anthracnose (Colletotrichum spp.): sunken lesions on the fruits

7. General crop management

The management of the pistachio includes the selection of cultivars adapted to the climate and the establishment of an adequate proportion of male and female plants. Pruning aims to balance the crown and favour light penetration. Controlled irrigation improves productivity, avoiding waterlogging. The control of scale insects, fruit moths and wood diseases is essential to maintain the longevity of the orchards. Harvesting is carried out when the outer hull separates naturally from the hard shell.

Bibliographic references

• EPPO Global Database – Pistacia vera
• CABI – Crop Protection Compendium – Pistacia vera L.
• Ferguson, L., et al. (2014). Pistachio production. Horticultural Reviews.
• FAO (2020). Mediterranean Tree Crop Management Manual.
• Michailides, T. J., et al. (2016). Diseases of pistachio. In: Tree Nut Diseases. Springer.
• Crane, J. C., et al. (2012). Pistachio botany and physiology. Acta Horticulturae.