Rambutan & Pomegranate | Subtropical and Temperate Fruit Production (HORMA201) - Unit 5 Notes - Chapter 22

Subtropical and Temperate Fruit Production

HORMA 201 - M.Sc. (Ag.) Horticulture

UNIT V: Minor fruits- Mangosteen, Carambola, Bael, Wood Apple, Fig, Jamun, Rambutan, Pomegranate

Table of Contents Commercial varieties of regional, national and international importance, Ecophysiological requirements, recent trends in propagation, rootstock influence, planting systems, cropping systems, root zone and canopy management, nutrient management, water management, fertigation, bioregulation, abiotic factors limiting fruit production, physiology of flowering, fruit set and development, abiotic factors limiting production, physiological disorders-causes and remedies, quality improvement by management practices; maturity indices, harvesting, grading, packing, precooling, storage, transportation and ripening techniques; industrial and export potential, Agri Export Zones(AEZ) and industrial support.

Chapter 22 - Rambutan & Pomegranate

🟣 RAMBUTAN (Nephelium lappaceum L.)

Family: Sapindaceae
Origin: Malaysia–Indonesia region (Malay Archipelago)
Chromosome number: 2n = 22
Edible part: Fleshy aril (sarcotesta)
Other names: “Hairy lychee” due to its appearance

🔹 1. Commercial Varieties (Regional, National, International)

International Varieties:

• Rongrien: Popular Thai variety, non-clinging seed, high yield
• Chompoo: Sweet taste, large size, pinkish-red
• Jitlee: Crisp flesh, good shelf life
• Binjai (Indonesia): High yield, firm pulp
• Lebakbulus: Smaller, juicy fruit, early maturity

India:

• Grown on a limited scale in Kerala, Karnataka, Tamil Nadu
• No well-established named varieties; trials ongoing with Thai/Indonesian introductions
• Selection from seedlings (e.g., ICAR-IIHR efforts)

🔹 2. Ecophysiological Requirements

• Climate:

• Strictly tropical, humid; unsuitable for dry or cold areas

• Requires high rainfall (>2,000 mm/year) and high humidity (≥75%)

• Temp range: 22–35°C

• Sensitive to frost and dry winds

• Soil:

• Deep, well-drained loam to clay loam

• Slightly acidic to neutral pH (5.5–6.5)

• Intolerant to water stagnation or saline soil

• Elevation: Performs well up to 600–900 m MSL

🔹 3. Propagation & Rootstock Influence

• Seed propagation: Used in the past; results in variability and longer juvenile period (6–8 years)

• Vegetative propagation:

• Approach grafting (most successful)

• Air layering: Moderate success with IBA treatment

• Budding and cuttings have lower success

• Rootstock:

• Own-rooted or seedling rootstock of Rambutan

• No intergeneric rootstocks like in citrus

🔹 4. Planting System

• Spacing:

• Standard: 8 × 8 m (around 150 trees/ha)

• HDP possible with 5 × 5 m spacing for dwarf types

• Pit size: 1 × 1 × 1 m with FYM, neem cake, and sand

• Best planting time: Onset of monsoon (June–July)

• Training: Single-stem training with 3–4 main branches at 1–1.5 m height

🔹 5. Cropping System, Root Zone & Canopy Management

• Cropping system: Intercropping discouraged due to shallow roots and high water requirement

• Canopy management:

• Prune after harvest to maintain umbrella shape

• Remove inward-growing branches and water sprouts

• Root zone:

• Mulching and maintaining moist soil is essential

• Avoid deep tillage due to shallow root system

🔹 6. Nutrient Management

• FYM: 25–30 kg/tree/year

• Recommended dose for mature trees:

• N: 300–400 g

• P₂O₅: 150–200 g

• K₂O: 250–300 g

• Apply in 2 splits (pre-flowering and fruit set stage)

• Micronutrient sprays (Zn, Fe, B) help in improving fruit quality

• Mulching and green manuring improve soil health

🔹 7. Water Management & Fertigation

• Very high water requirement

• Irrigation schedule:

• Weekly irrigation during dry season

• Drip irrigation is preferred to maintain constant soil moisture

• Fertigation:

• NPK water-soluble fertilizers via drip improve yield in intensive systems

• Helps in reducing nutrient leaching in high rainfall zones

🔹 8. Bioregulation

• GA₃ (20–40 ppm): Enhances fruit size and uniformity

• NAA (15–20 ppm): Reduces fruit drop

• Paclobutrazol (PBZ): Used experimentally to induce flowering during off-season

• Not much standardized data in Indian conditions; research is ongoing

🔹 9. Flowering, Fruit Set & Development

• Flowering season: January–March (South India)

• Inflorescence: Panicle, terminal, yellowish flowers

• Pollination:

• Cross-pollinated; both male and hermaphrodite flowers occur

• Insect-pollinated (bees, flies)

• Fruit set:

• Only 1–3% of flowers set into fruits naturally

• Requires pollinizers and healthy pollinator activity

• Fruit development: 90–120 days

• Fruit maturity: May–July

🔹 10. Abiotic Factors Limiting Fruit Production

• Low humidity or prolonged drought → poor flowering, flower drop, fruit cracking

• High winds → damage to branches and panicles

• Water stagnation → root rot, fungal infections

• Frost/cold spells → complete failure of flowering

• High soil pH (>7.5) → micronutrient deficiency (especially Fe and Zn)

🔹 11. Physiological Disorders – Causes & Remedies

Disorder	Cause	Remedy
Fruit cracking	Sudden rainfall after dry spell	Regular irrigation, mulching
Poor fruit set	Pollination failure, lack of pollinizers	Plant male pollinizers, attract bees
Internal browning	Post-harvest oxidation	Quick cooling, reduce storage temp
Small-sized fruits	Nutrient deficiency, water stress	Balanced nutrition and watering

🔹 12. Quality Improvement by Management Practices

• Irrigation at fruit set and maturity: Increases size, reduces cracking

• Use of micronutrients (Zn, B, Fe): Improves skin color and pulp development

• Thinning of fruits: Encourages uniform, larger fruit development

• Mulching and organic matter: Improves root zone moisture and microbial health

• Use of GA₃ and NAA: Enhances fruit firmness, reduces drop

🔹 13. Maturity Indices, Harvesting & Post-Harvest Handling

✅ Maturity indices:

• Bright red or yellow color with soft, spiny rind

• Full swelling of the fruit

• Aril easily separates from seed in good cultivars

• Fruit becomes juicy and sweet

✅ Harvesting:

• By hand or secateurs: Entire fruit clusters are cut

• 2–3 pickings needed due to non-uniform ripening

• Yield:

• Young trees (5–6 years): 10–15 kg/tree

• Mature trees (>10 years): 80–100 kg/tree

✅ Grading & Packing:

• Graded by size and skin color (red/yellow)

• Packed in perforated plastic crates or boxes with cushioning

• High perishability — handle with care

✅ Precooling & Storage:

• Precooling at 10–12°C immediately after harvest increases shelf life

• Storage temp: 10–12°C, RH 90–95%

• Shelf life: 5–7 days (ambient), 10–14 days (cold storage)

• Modified Atmosphere Packaging (MAP) improves transportability

✅ Ripening:

• Non-climacteric fruit — does not ripen after harvest

• Should be harvested when fully ripe

🔹 14. Industrial & Export Potential

• Processed forms: Canned arils, juices, jams, jellies, wines

• Aril has high sugar content, vitamin C, and antioxidants

• Seed oil is edible and used in soaps and cosmetics

• Export potential to ethnic markets (especially Thai, Indonesian diaspora)

• Frozen and canned products preferred for export

• Constraints:

• High perishability

• Lack of cold chain infrastructure

• Still in early stages in India

🔹 15. Agri Export Zones (AEZ) & Industrial Support

• No specific AEZ for Rambutan in India

• Included in exotic fruit clusters under MIDH in Kerala, Karnataka

• Encouraged under One District One Product (ODOP) in some southern districts

• Support programs:

• MIDH (Mission for Integrated Development of Horticulture)

• PMFME (food processing)

• NHB and APEDA initiatives for exotic fruits

• Potential for startup funding in processed Rambutan products

🔴 POMEGRANATE (Punica granatum L.)

Family: Lythraceae (previously Punicaceae)
Origin: Iran to Northern IndiaChromosome number: 2n = 16
Edible part: Fleshy seed coat (aril)
Type of fruit: Balausta (a modified berry)
Inflorescence: Solitary or cymose

🔹 1. Commercial Varieties – Regional, National, International Importance

National (India):

• Bhagwa: Most widely grown, bright red arils, soft seeds, good shelf life

• Ganesh: Pinkish arils, soft seeds, medium size, early maturing

• Arakta: Deep red arils, soft seeds, heavy yield

• Mridula: Soft seeds, sweet taste, good juice recovery

• Ruby: Dwarf plant, good for high-density planting

• Phule Bhagwa Super: Selection of Bhagwa with better yield and disease resistance

• Sinduri, Jyoti, Dholka: Regional/local varieties

International:

• Wonderful (USA): Deep red rind and arils, tart taste

• Kandhari (Afghanistan): Sweet-sour, large fruit

• Spanish Ruby (Spain): Juicy, red pulp

• Sweet Alandi (Iran): Sweet, high juice content

India is the largest producer and exporter of pomegranate.

🔹 2. Ecophysiological Requirements

• Climate:

• Grows in semi-arid to arid subtropics

• Requires hot, dry summer and cool winter

• Tolerates drought better than frost

• Rain during flowering and fruiting leads to fruit cracking

• Soil:

• Tolerant to a range of soils – sandy loam to clay loam

• Well-drained, fertile soils preferred

• pH: 6.0–7.5

• Sensitive to water stagnation

• Elevation: Grows well up to 500–1000 m MSL

🔹 3. Propagation & Rootstock Influence

• Softwood cuttings (best): Treated with IBA (1000 ppm)

• Air layering, hardwood cuttings, and tissue culture also practiced

• Rootstocks: No commercial rootstocks; seedling rootstocks commonly used

• Micropropagation: Being developed for virus-free planting material

🔹 4. Planting Systems

• Spacing:

• Normal: 4 × 4 m (625 plants/ha)

• High-density: 2.5 × 4 m or 3 × 3 m

• Pit size: 60 × 60 × 60 cm, filled with FYM, neem cake, and soil

• Season: Monsoon or spring (June–August or February–March)

• Training: Modified central leader or open center

• Remove basal suckers regularly

🔹 5. Cropping Systems, Root Zone & Canopy Management

• Cropping system:

• Mostly monocrop

• Can be intercropped with short-duration legumes in early years

• Canopy management:

• Regular pruning of diseased, dry, crossing branches

• Maintain open center for good light penetration

• Prune annually after harvest (hard pruning every 3–4 years)

• Root zone:

• Mulching conserves moisture

• Avoid deep cultivation near root zone

🔹 6. Nutrient Management

FYM: 10–20 kg/tree/year (young), up to 40 kg for mature trees

Tree age (years)	N (g/tree)	P (g/tree)	K (g/tree)
1–2	250	125	125
3–5	500	250	250
>5	625–750	375–400	400–500

• Micronutrients:

• Foliar sprays of Zn, Fe, B during flowering & fruit set

• Use of Azospirillum and PSB improves availability

• Split application (at pruning, flowering, fruit set stages)

🔹 7. Water Management & Fertigation

• Drought-tolerant, but regular irrigation enhances yield and quality

• Critical stages: Flowering, fruit set, and fruit development

• Drip irrigation: Preferred – improves water and fertilizer efficiency

• Fertigation: Use of water-soluble NPK (19:19:19 or 0:52:34) beneficial

• Waterlogging must be avoided at all costs

🔹 8. Bioregulation

• Bahar treatment: Regulates flowering and cropping season

• Mrig Bahar (June–July) – flowering in monsoon, harvesting in winter

• Ambia Bahar (Jan–Feb) – flowering in spring, harvesting in rainy season

• Hasta Bahar (Sept–Oct) – flowering in autumn, harvesting in summer

• Methods of bahar regulation:

• Withhold irrigation for 1–2 months

• Root exposure & light root pruning

• Application of ethrel (2 ml/L) or CCC (500 ppm)

• Followed by pruning + irrigation + fertilizer

• Growth regulators:

• GA₃ (25–50 ppm): Improves fruit set

• NAA (20–30 ppm): Reduces fruit drop

• Ethrel: Flower thinning and off-season flowering

• 2,4-D (5–10 ppm): Increases fruit retention

🔹 9. Abiotic Factors Limiting Production

Factor	Impact
Water stress	Reduces fruit size and juice content
High humidity/rainfall	Fruit cracking, fungal diseases
Frost	Affects young shoots and flowers
Calcareous soils	Leads to iron/zinc deficiency
High wind	Fruit drop, cracking

🔹 10. Physiology of Flowering, Fruit Set & Development

• Flower types:

• Hermaphrodite (perfect) – fruit-bearing

• Male – sterile

• Intermediate – rarely fertile

• Pollination: Cross-pollinated by insects (entomophilous)

• Fruit set: 30–40% in open pollination; hand pollination improves yield

• Fruit development: 120–150 days after flowering

• Yield:

• 1–2-year-old: 5–10 kg/tree

• 6–8-year-old: 40–60 kg/tree

• Commercial: 12–15 t/ha (can go up to 25 t/ha under ideal conditions)

🔹 11. Physiological Disorders – Causes & Remedies

Disorder	Cause	Remedy
Fruit cracking	Sudden water uptake after dry spell, boron deficiency	Uniform irrigation, B sprays (0.2%)
Internal breakdown	High temperature, delayed harvest	Timely harvest, avoid over-ripening
Sunscald	Exposure to direct sunlight	Use of shade net or maintain canopy
Flower/fruit drop	Nutritional deficiency, water stress	NAA spray (20–30 ppm), balanced nutrition

🔹 12. Quality Improvement by Management Practices

• Balanced nutrition → improves aril size, sweetness, rind color

• Micronutrients (Zn, Fe, B) → improve internal quality

• Proper bahar management → synchronizes flowering and harvesting

• Fruit thinning → larger and uniform fruits

• Use of bioregulators (GA₃, NAA) → enhance retention and size

• Avoid stress → prevents cracking and disorders

🔹 13. Maturity Indices, Harvesting & Post-Harvest Handling

✅ Maturity indices:

• Days from flowering: ~120–150

• Fruit develops characteristic red or yellow color depending on variety

• Metallic sound when tapped

• Flatness of fruit sides and softness of blossom end

✅ Harvesting:

• Hand harvesting with secateurs

• Avoid damage to fruit skin (susceptible to rotting)

• Harvesting period varies with bahar

✅ Grading & Packing:

• Graded by size, weight, and skin color

• Packed in corrugated fiberboard boxes or wooden crates with soft lining

• Export-grade fruits are waxed and packed in 3-layered boxes

✅ Precooling & Storage:

• Precooling at 8–10°C for 6–8 hours

• Storage: 6–8°C, RH 90–95%

• Shelf life: 6–8 weeks

• Controlled Atmosphere (CA) or Modified Atmosphere Packaging (MAP) used for export

✅ Ripening:

• Non-climacteric – no ripening after harvest

• Harvest only when fully mature

🔹 14. Industrial & Export Potential

• Juices, syrups, jams, anardana, and wine

• Pharmaceutical & cosmetic uses: Antioxidant, anti-inflammatory properties

• By-products: Peel used for dye, medicinal extracts

• Export destinations: UAE, Netherlands, UK, Saudi Arabia, Bangladesh

• India is the largest exporter of fresh pomegranate

• Challenges:

• Post-harvest diseases

• Cracking

• International residue limits and quarantine issues

🔹 15. Agri Export Zones (AEZ) & Industrial Support

• AEZ for Pomegranate: Maharashtra (Solapur, Ahmednagar, Sangli)

• Support programs:
  
  

• NHB (post-harvest infrastructure)

• APEDA (exports, quality certifications)

• PMFME & MIDH (processing & cluster development)

• MahaAnar (Maharashtra Pomegranate Growers Association) supports export-quality production

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