Table of Contents
Introduction of Ramphal
Names and Uses
- Common names: Jamaican apple, bullock’s heart, netted custard apple, luvun, nonai, ramphal
- Crushed leaves/paste used for internal and external wounds and boils
- Leaf decoction used in gastritis
- Leaf juice used as a vermifuge
- Unripe dried fruits use
Nutritive Value and Composition
- Pulp: Creamy yellow, sweet, low acidity, poor flavor compared to cherimoya and sugar apple
- Nutritional composition per 100g: 76.2g water, 1.1-1.8g protein, 0.33g lipids, 18.7g carbohydrates, 2.6g fiber, 0.38-0.77g total acidity, 56-98 calories energy, 21-24.0mg calcium, 20-27mg phosphorus, 0.4-1.0mg iron, 0.28mg vitamin A, 28-32mg ascorbic acid, 0.26% fat
Origin and Distribution
- Native to the West Indies
- Carried to Central America and southern Mexico in early times
- Found naturally cultivated in Peru and Brazil
- Commercially grown in the Bahamas, Bermuda, southern Florida
- Introduced to African and Asian countries many years ago
- Widely distributed in tropical and subtropical regions
- In India, commercially used as a table fruit and cultivated in Bengal and southern parts
Botanical Description
- Growth Habit: Erect, 5.0-8.5m height, rounded or spreading crown, cylindrical trunk and stems with lenticels and short coffee-colored hairs
- Leaves: Deciduous, alternate, oblong or narrow lanceolate, 15-25cm x 2-5.6cm, with 10-20 conspicuous pairs of veins
- Leaves: Deciduous, alternate, oblong or narrow lanceolate, 15-25cm x 2-5.6cm, with 10-20 conspicuous pairs of veins
- Flowers: Axillary, drooping clusters (3-10), mild fragrance, 3 fleshy and narrow yellowish-green petals (2-3cm long), light green externally, pale yellow with a dark red or purple spot at the base, pedicels 1.5-3.0cm
- Flowering: July to October (wet to dry season)
- Fruit: Compound, 0.1-0.8kg weight, 8-16cm diameter, 10-12cm length, symmetrically heart-shaped, conical, irregular, or nearly round/oblate with a basal depression, reddish-yellow surface, coriaceous, impressed lines above the carpels, thick cream-white custard-like granular pulp surrounding moderately juicy segments, 45-75 hard, brown or black, glossy seeds (<1.25cm long)
Climate and Soil
- Prefers warm, humid (tropical) climate for growth and fruit development
- Also survives well in subtropical conditions
- Frost and cool-sensitive, less drought-tolerant than custard apple
- Grows from sea level to 1,500m in Central and South America
- In India and the subcontinent, grows from plains up to 1,220m elevation
- Sheds leaves at the onset of cold weather and goes dormant
- Can survive 32°C without serious harm but with low bearing and fruiting
- Not very drought-tolerant, prefers more humid atmosphere than other Annona species
- Well-adapted to adverse soil conditions, pH 5.0-8.0
- Survives best in low-lying, deep, rich soils with ample moisture and good drainage
- Reported to be a good rootstock for cherimoya and soursop
Propagation and Rootstock
- Propagated by sexual (seeds) and asexual methods
- Seeds should be from mother plants with high yield, good fruit quality, and biotic/abiotic stress resistance
- Uneven and irregular seed germination, rapid loss of viability (6-7 months)
- Seeds germinate within 30-35 days after sowing
- Seedlings require 3-4 years for fruit bearing
- Seed scarification and water immersion improve germination
- GA3 (10,000 ppm) significantly increases seed germination
- Commercially propagated by budding (shield, inverted T) and grafting (splice, cleft) with 45-80% success
- Grafted and budded plants grow faster and bear earlier than seedlings
- Maximum bud take in August (74.44%), followed by July (69.99%) and April (65.55%)
Varieties
- No commercial varieties available, only local selections in cultivated areas
Crop Improvement
- Conventional methods like selection and introduction of superior genotypes/cultivars
- Hybridization to develop different populations for selecting superior clones
- No specific breeding program for Annona reticulata, although breeding work has been done on other species like cherimoya and squamosa
Orchard Management
- Intercropping with legumes, peas, beans, and marigold flowers in young orchards for additional income and weed control
- No crops during winter as plants go under rest
- Gap filling for mortality in new orchards
- Stagnation of water during first monsoon increases mortality
Nutrition
- Generally, no manures or fertilizers are applied
- For better fruit setting and quality, application of manures or fertilizers is useful
- An annual dose of 50:50:25g NPK along with 15kg FYM is sufficient for custard apple
- Increase the dose up to 5 years of age, then a fixed dose every year
- Apply full FYM, phosphorus, potash, and half nitrogen during monsoon, and remaining nitrogen during spring
Tree Management
- Fast-growing, responds well to mulching, organic fertilizers, and frequent irrigation during dry weather
- Training and pruning improve tree form
- Single stem up to 50-70cm height, then inducing scaffold branches in all directions for a strong framework
- Pruning limited to removing crisscross, dry, and overlapping branches
- A full-grown tree can produce 30-45kg of fruits/year with proper management
Harvesting and Post-Harvest Management
- Harvest at proper maturity when skin turns reddish-yellow in the interspaces between protuberances
- Poor shelf life (3-5 days)
- For distant markets, harvest at a comparatively harder stage
- Exhibits climacteric fruit features with respiration peak and increased ethylene production after harvest
- Store at 15-16°C with high relative humidity
- Mainly consumed fresh, can be used for nectar, drinks, sherbets, and ice cream