Custard apple

Annona spp.

1. Identification and origin

Annona spp. is a genus of the Annonaceae family that includes several species of tropical and subtropical fruit trees, generically known as annonaceous fruits. The species of greatest agricultural interest are Annona cherimola Mill. (cherimoya), A. squamosa L. (sugar apple, custard apple), A. muricata L. (soursop) and hybrids such as A. cherimola × A. squamosa (atemoya). The genus is native to tropical America and has been spread to subtropical regions throughout the world.

2. Economic importance

Annonaceous fruits have growing economic importance due to the commercial value of the fruits, appreciated fresh and used in juices, desserts and processed products. The cherimoya and atemoya are particularly valued in premium markets for their creamy texture and intense aroma. Soursop has additional demand in the juice and nutraceutical products industry. The crop is relevant in tropical and subtropical regions, including coastal areas and sheltered valleys.

3. Botanical characterisation

Trees or shrubs of medium size, with simple, entire and alternate leaves. The flowers are solitary or in small groups, with thick petals and a greenish or yellowish colouring. The fruits are compound (syncarps), with an epidermis that varies according to the species: smooth (A. cherimola), scaly (A. squamosa) or spiny (A. muricata). The pulp is white, aromatic and contains numerous seeds. Reproduction is carried out by seed or by grafting, the latter being preferred for production uniformity.

4. Soil and climate requirements

Annonaceous fruits prefer tropical and subtropical climates, with optimal temperatures between 18–28 °C. A. cherimola tolerates cold better and adapts to subtropical climates; A. squamosa and A. muricata require higher temperatures. They require well-drained, deep and fertile soils, with a pH between 6.0–7.5. They are sensitive to waterlogging and strong winds, which cause flowers and fruits to drop.

5. Main pests

• Fruit fly: Ceratitis capitata causes damage to ripe fruits.
• Scale insects (Coccoidea): sap sucking and honeydew production.
• Mites (Tetranychidae): silvering and reduction of the photosynthetic area.
• Fruit and branch borers: chewing insects that cause perforations.
• Aphids (Aphididae): deformations and transmission of viral diseases.

6. Main diseases

• Anthracnose: Colletotrichum gloeosporioides causes spots and rots on fruits and leaves.
• Root rots: Phytophthora spp. in poorly drained soils.
• Leaf spot: Cercospora spp. causes leaf necrosis.
• Cankers: opportunistic fungi on weakened branches.
• Post-harvest rots: saprophytic fungi under inadequate storage conditions.

7. General crop management

It includes the use of quality grafted plants, planting in sheltered locations and well-drained soils, balanced fertilisation and regular irrigation without waterlogging. Manual pollination is frequently necessary in A. cherimola and hybrids to ensure adequate fruit set. Training and cleaning pruning improves ventilation and reduces sanitary problems. Harvesting should be carried out when the fruit reaches the appropriate physiological stage, completing ripening off the tree.

Bibliographic references

• EPPO Global Database – Annona spp..
• CABI – Crop Factsheets – Annona spp..
• FAO – Technical documents on tropical fruit trees.
• Paull, R. E., & Duarte, O. (2011). Tropical Fruits. CABI.
• Morton, J. (1987). Fruits of Warm Climates (chapters on Annona spp.).
• George, A. P., & Nissen, R. J. (1992). The cherimoya (Annona cherimola Mill.). Horticultural Reviews.