Introduction

Custard apple, also known as sitaphal or sugar apple, is a popular fruit of the dry region due to its sweet and delicate flesh. It belongs to the Annonaceae family and is a deciduous or semi-deciduous woody shrub reaching a height of 5-6 meters. The fruit is rich in carbohydrates (23.5% sugar), protein (1.6%), calcium (17 mg/100g), phosphorus (47 mg/100g), and iron (1.5 mg/100g).

Key Features of Custard Apple

• Botanical Name: Annona squamosa
• Family: Annonaceae
• Common Names: Sitaphal (India), Sugar Apple (English), Sweetsop
• Origin: West Indies and South America
• Plant Type: Deciduous or semi-deciduous small tree/shrub (5-6 m tall)
• Fruits: Round, heart-shaped, or irregular, covered with knobby scales
• Pulp: Sweet, creamy white, with black seeds
• Nutritional Value (per 100g):
  • Carbohydrates: 23.5% (mainly sugar)
  • Protein: 1.6%
  • Calcium: 17 mg
  • Phosphorus: 47 mg
  • Iron: 1.5 mg
  • Vitamin C: Present in good amounts

Related Species

• Bullock’s Heart / Ramphal (Annona reticulata): Larger, heart-shaped fruits with smooth skin, fewer seeds, but inferior pulp quality.
• Soursop (A. muricata): Fruits with soft spines, highly acidic pulp.
• Cherimoya (A. cherimola): Slightly acidic, sweet fruit with a buttery consistency and fewer seeds.
• Atemoya (A. squamosa × A. cherimola): Hybrid with the superior taste of cherimoya and adaptability of sugar apple.

The fruit is used as a dessert, in ice creams, jams, and jellies.

Climate and Soil Requirements

• Prefers a warm climate with high humidity and mild winters.
• Tolerates extreme temperatures from below freezing to 40°C, but such extremes affect fruiting.
• Thrives from sea level up to 1000 meters.
• Annual rainfall of 500-750 mm is adequate.
• Cherimoya (A. cherimola) prefers cooler climates, while atemoya withstands higher temperatures.
• Can be grown in varied soil types, including rocky, marginal, and waste lands.
• Best yield in well-drained fertile soil with neutral pH.
• Grows in slightly alkaline soil and tolerates mildly saline irrigation water.

Cultivars

• Balanagar: Greenish-yellow fruits (130-140 g), TSS 20.7° Brix.
• Red Sitaphal: Pinkish dark fruits with red pulp (150-160 g), TSS 22.3° Brix.
• Mammoth: Green fruit (125 g), TSS 20° Brix.
• African Pride: Popular cultivar of Atemoya in Australia.
• Pink Mammoth: Juicy pulp with an excellent acidic flavor.
• Arka Sahan: Hybrid (210 g), waxy light green skin, TSS 30° Brix, yield 12 t/ha.
• APK (Ca)-1: Developed in Tamil Nadu, high yielder (14.90 kg/tree), TSS 24.5° Brix.

Propagation and Planting

• Propagated by seeds (germination in 20-30 days), but vegetative propagation (budding/inarching) ensures genetic uniformity.
• Budding: Done in early spring/autumn.
• Inarching: Uses one-year-old scion and rootstock.
• Spacing: 5 m × 5 m.
• Soil treatment at planting:
  • 50 g Phosphobacterium + 150 g Vesicular Arbuscular Mycorrhiza (VAM) to improve root growth.
  • 10 kg FYM mixed with topsoil.

Nutrient and Water Management

• Manuring:
  • 10 kg FYM, 250 g N, 125 g P₂O₅, 250 g K₂O per tree.
  • Apply at the start of the rainy season.
• Irrigation:
  • Black polythene mulch reduces irrigation needs.
  • Annual water requirement: 777.6 liters/tree.

Intercropping Suitable intercrops in young orchards: Groundnut, minor millets, cowpea, linseed.

Special Cultural Operations

• Poor fruit set issue:
  • Gibberellic Acid (GA) 50 ppm: Dipping freshly opened flowers ensures better fruit set.
  • NAA 20 ppm: Spraying four times at weekly intervals during flowering (March-April) improves fruit retention.
• Mulching and irrigation during summer prevent fruit drop.

Pests and Diseases Management

Pests

Mealybugs (Ferrisia virgata, Maconellicoccus hirstus): Cause blemishes on fruits. Control: Spray 0.05% dichlorvos.

Diseases

• Leaf Spot: Causes premature leaf drop. Management: Fortnightly sprays of 0.05% carbendazim.
• Anthracnose (Glomerella cingulata): Blossom-end infection leads to shriveling. Management: Spray Indofil M-45 (0.02%) at 15-day intervals.

Harvest and Storage

Harvesting Indicators

• Light green fruit color.
• Yellowish-white color between carpels.
• Initial cracking between carpels.
• Peak harvest: October – November.
• Yield: 80-100 fruits/tree after 4-5 years.

Storage Conditions

• Ripening period: A few days after harvest.
• Cold storage: 15-20°C, RH 85-90%, 10% CO₂.
• Storage life: 12-18 days under ideal conditions.
• Prolonging pulp storage:
  • Saccharified starch (1:1), high-voltage treatment, nitrogen gas cover, sugar (1:2).
  • Shelf life: 45 days at 4°C, 90 days at -18°C.

Yield of Custard Apple (Annona squamosa)

• Per Tree Yield:
  • Young Tree (5–10 years): 10–20 kg/tree
  • Mature Tree (10+ years): 20–50 kg/tree
• Per Hectare Yield:
  • Normal Conditions: 8–10 tons/ha