Guava tree

Psidium guajava

1. Identification and origin

The guava tree (Psidium guajava L.), belonging to the Myrtaceae family, is an arboreal species originating in Tropical America, from Mexico to Brazil. It is widely naturalized in tropical and subtropical regions throughout the world, being one of the most cultivated tropical fruit trees. The genus Psidium includes more than 100 species, but P. guajava is the most economically important.

2. Economic importance

The guava is valued for fresh consumption, juices, pulps, jams and industrial products. It stands out for its high content of vitamin C, fibre and antioxidant compounds. Countries such as India, Brazil, Mexico, Egypt and Thailand are major producers. The crop is of growing interest in warm Mediterranean regions due to its hardiness and good productivity.

3. Botanical characterization

An evergreen tree or shrub, 3–10 m tall, with a dense crown and quadrangular branches. The leaves are opposite, elliptical, with well-marked veins. The flowers are white, hermaphrodite, with numerous stamens. The fruit is a rounded or pear-shaped berry, with a thin skin, white, pink or red pulp, with hard and numerous seeds. The root system is deep and well adapted to poor soils.

4. Soil and climate requirements

It adapts well to tropical and subtropical climates, tolerating dry periods after establishment. It prefers temperatures between 20–30 °C, being sensitive to frost. It requires well-drained soils, of medium texture, with a pH between 5.0 and 7.0. It tolerates poor soils, but responds well to organic matter and regular irrigation during fruiting.

5. Main pests

• Fruit fly (Ceratitis capitata, Anastrepha spp.): main pest, causing internal damage and fruit drop.
• Thrips (Frankliniella spp.): floral damage and scarring on the fruits.
• Scale insects (Coccoidea): sap sucking and honeydew production.
• Mites (Tetranychus urticae, Brevipalpus phoenicis): chlorosis and reduced vigour.
• Stem and branch borers (Coleoptera): galleries and decline of the plant.

6. Main diseases

• Anthracnose (Colletotrichum gloeosporioides): leaf spots and rots on fruits.
• Guava canker (Nectria haematococca): woody lesions and dieback of branches.
• Root rots (Phytophthora spp.): wilt and death of plants in waterlogged soils.
• Rust (Puccinia psidii): yellow pustules on the leaves, common in Myrtaceae.
• Bacterial wilt (Ralstonia solanacearum): serious disease in humid tropical regions.

7. General crop management

This includes choosing varieties adapted to the local climate, planting in well-drained soils, formative and fruiting pruning for crown aeration, regular irrigation during fruit development, balanced fertilization, monitoring of pests and diseases and harvesting at the ideal point of maturity. Control of the fruit fly is essential to ensure commercial quality.

Bibliographic references

• EPPO Global Database. Psidium guajava – pests and diseases.
• CABI Invasive Species Compendium. Psidium guajava – datasheets.
• Singh, G. (2011). Guava. In: Mitra, S. K. (Ed.), Tropical and Subtropical Fruits. CABI.
• Paull, R. E., & Duarte, O. (2012). Psidium guajava. In: Tropical Fruits. CAB International.
• Babu, K. N., Ravishankar, K. V., & Krishnan, R. (2016). Guava. In: Rajasekaran, P., et al. (Eds.), Fruit Breeding. Springer.