Pear tree

Pirus spp.

1. Identification and origin

The pear tree (Pirus spp.) is an arboreal species of the Rosaceae family, native to the temperate regions of Eastern Europe and Western Asia. Among the best-known species are P. communis L., P. pyrifolia (Burm.f.) Nakai and P. ussuriensis Maxim., widely used both in commercial production and in breeding programmes. The crop was widely spread along the Mediterranean and Central Europe, and is currently one of the main temperate-climate fruit trees. In Portugal, it is cultivated mainly in the Oeste, the Ribatejo and the Beira Interior, with the ‘Rocha’ variety standing out.

2. Economic importance

The pear tree has high economic importance in the Portuguese fruit-growing sector, with strong expression in exports, especially of the ‘Rocha’ variety. The fruit is consumed fresh, processed or used in the jam and juice industry. The crop has high commercial value, but requires rigorous plant protection management due to its susceptibility to various pests and diseases.

3. Botanical characterisation

A medium-sized deciduous tree, 3–5 m in height, presenting a pyramidal or rounded crown. The leaves are simple, ovate and with a smooth or slightly serrated margin. The flowers are white, grouped in corymbs, with early flowering. The fruit is a pome, varying in shape, size and texture according to the cultivar. The root system is deep, benefiting from well-drained soils.

4. Soil and climate requirements

The pear tree adapts to temperate climates, requiring chilling hours for good floral differentiation. It prefers moderate temperatures and is sensitive to late frosts during flowering. It develops best in deep, well-drained soils, with a loamy to clay-loam texture and a pH between 6.0 and 7.5. It is sensitive to waterlogging and to soil compaction. Regular watering is essential in regions with a dry summer.

5. Main pests

• Pear psylla (Cacopsylla pyri): honeydew, sooty mould and vegetative decline
• Codling moth (Cydia pomonella): galleries in the fruit
• Leaf miner (Leucoptera malifoliella): leaf galleries
• Aphids (Aphididae): leaf curling and transmission of viruses
• Mites (Panonychus ulmi, Tetranychus spp.): chloroses and reduction of photosynthesis
• Thrips (Thysanoptera): leaf lesions and scarring on the fruit
• Nematodes (Meloidogyne spp.): root galls and decline in infested soils

6. Main diseases

• Fire blight (Erwinia amylovora): necroses, wilting and death of branches
• Scab (Venturia pyrina): leaf spots and lesions on the fruit
• Brown spot (Stemphylium vesicarium): leaf spots and rots
• Cankers and rots (Nectria galligena, Phytophthora spp.): necroses and decline
• Rust (Gymnosporangium sabinae): orange spots on the leaves
• Pear stripe virus (PStV): mosaic symptoms and reduction of productivity

7. General crop management

The management of the pear tree includes the choice of rootstocks adapted to the soil and the desired vigour, formation and fruiting pruning, and regular watering in critical periods. The control of the psylla is essential, resorting to monitoring, traps and integrated strategies. Crown ventilation and the reduction of leaf moisture are important to minimise diseases such as scab and brown spot. Harvesting should be carried out at the stage of physiological maturity appropriate to the commercial destination.

Bibliographic references

• EPPO Global Database – Pirus spp.
• CABI – Crop Protection Compendium – Pirus communis
• Webster, A. D., et al. (2015). Pear production and rootstock interactions. Acta Horticulturae.
• FAO (2020). Temperate Fruit Production Manual.
• Sutton, T. B., et al. (2014). Compendium of Apple and Pear Diseases and Pests. APS Press.
• Elkins, R., et al. (2019). Advances in pear orchard systems. Horticultural Reviews.