Subtropical and Temperate Fruit Production
HOR-MA201
UNIT I: Apple, Pear, Quince, Grapes
Chapter 1 -
🍎 APPLE (Malus domestica)
Family: Rose family (Rosaceae)
Commercial Varieties of Regional, National, and International Importance
Global Perspective:
Apple is the most important temperate fruit globally and ranks fourth among the most widely produced fruits after banana, orange, and grape.
Thousands of varieties exist, with significant diversity due to the heterozygous nature of apples.
Major international cultivars:
Red Delicious, Golden Delicious, Fuji, Granny Smith, Gala, Jonagold, Braeburn, Idared, Elstar, Pinova, Topaz, Cripps Pink (Pink Lady), Honeycrisp.
In the US and Europe, branded and managed varieties (e.g., Envy, SweeTango, RedPop) are gaining ground for their unique traits and market appeal.
India:
Leading varieties: Red Delicious group (predominant in Kashmir), Ambri, Maharaji, American Apirouge, Tydeman’s Early, Granny Smith, Golden Delicious, Royal Delicious, McIntosh, Jonathan, and new introductions like Gala Mast, Red Velox, Red Chief.
Cultivation is concentrated in Jammu & Kashmir, Himachal Pradesh, Uttarakhand, and parts of the North-East.
Ecophysiological Requirements
Climate:
Requires a temperate climate with cold winters for dormancy (chilling requirement: 800–1,600 hours below 7°C).
Sensitive to late spring frosts, hail, and high summer temperatures.
Soil:
Deep, well-drained loamy soils with a pH of 5.5–6.5 are ideal.
Avoid heavy clay, saline, or poorly drained soils.
Recent Trends in Propagation and Rootstock Influence
Propagation: Apples are propagated by grafting (whip, tongue, or cleft) and budding onto selected rootstocks.
Rootstock Influence:
Rootstocks determine tree size, precocity, productivity, disease resistance, and adaptability.
Seedling rootstocks: Vigorous, deep-rooted, late bearing, and variable.
Clonal rootstocks (Malling, Malling-Merton, Budagovsky, Geneva series):
M.9, M.27: Dwarfing, early bearing, suitable for high-density planting but need support and irrigation.
MM.106, MM.111: Semi-dwarfing, good for medium-density orchards, better anchorage and drought tolerance.
B.9, G.41, G.935, G.202: Newer rootstocks with improved disease resistance and size control.
Rootstock-scion interaction significantly affects graft success, growth, yield, and fruit quality.
In India, most traditional orchards are on seedling rootstocks, but adoption of clonal rootstocks is increasing for uniformity and higher productivity.
Planting Systems and Cropping Systems
Planting Systems:
Square and rectangular layouts are common; high-density planting (HDP) with dwarf/semi-dwarf rootstocks is expanding.
Spacing: 6–7 m (seedling), 3–4 m (semi-dwarf), 1.5–2.5 m (dwarf).
Cropping Systems: Intercropping with legumes or vegetables is feasible in young orchards.
Root Zone and Canopy Management
Root Zone:
Deep tillage and organic amendments before planting.
Mulching for moisture conservation and weed control.
Canopy Management:
Central leader, spindle bush, and slender spindle are popular training systems.
Annual pruning to maintain fruiting wood, remove dead/diseased branches, and regulate crop load.
Nutrient Management
Apply FYM and balanced NPK based on soil and leaf analysis.
The recommended NPK dose for apple (Malus domestica) varies based on factors like age of the tree, soil fertility, climate, rootstock type, and fruit load.
For 1st year of plant - 35g N, 70g P₂O₅ & 100g K₂O.
Micronutrient sprays (boron, zinc, iron) correct common deficiencies.
Fertilizer doses increase with tree age and vary by rootstock vigor.
Water Management
Regular irrigation is crucial during flowering, fruit set, and fruit development.
Drip irrigation and fertigation are preferred for efficient input use, especially in HDP orchards.
Fertigation
Soluble fertilizers like urea, NPK applied via drip
Improves uptake and reduces nutrient loss
Bioregulation
Growth Regulators:
Use of gibberellins, cytokinins, and ethephon for fruit thinning, size enhancement, and color development.
Dormex (hydrogen cyanamide) may be used to break dormancy in areas with insufficient chilling.
Promalin (GA₄+₇ + BA) for elongation and size improvement
Abiotic Factors Limiting Fruit Production
Chilling Insufficiency: Leads to poor bud break and reduced yield.
Frost, hail, drought, and high temperatures can cause flower/fruit drop, sunburn, and reduced quality.
Soil constraints: Poor drainage or salinity limits tree growth.
Sunburn and water stress during fruit development
Physiology of Flowering, Fruit Set, and Development
Flowering: Initiated after chilling; occurs on spurs and shoots of 2+ year-old wood.
Pollination: Most cultivars require cross-pollination; bees are primary pollinators.
Fruit Set and Development: Influenced by carbohydrate reserves, hormones, and environmental conditions. Fruit set improved by honey bee pollination
Bud differentiation in summer.
Parthenocarpy absent; requires fertilization
Physiological Disorders – Causes and Remedies
Biennial Bearing: Managed by thinning flowers/fruits and balanced nutrition.
Bitter Pit: Due to calcium deficiency, controlled by foliar calcium sprays.
Sunburn and Fruit Cracking: Mitigated by proper canopy management and regulated irrigation.
Internal browning: Low temperature storage issues
Water core: Excess sugar in cells
Sunscald: High temperature; use shade nets or cover crops
Core rot are also noted in some cultivars.
Quality Improvement by Management Practices
Balanced nutrition, irrigation, fruit thinning, and canopy management improve fruit size, color, TSS, and storage life.
Integrated pest and disease management reduces blemishes and postharvest losses.
Thinning of flowers and fruits
Use of bioregulators
Maturity Indices
Days from full bloom: 130–150 days
Change in background color, firmness, TSS (12–14°Brix)
Starch pattern index
Harvesting, Grading, Packing, Precooling, Storage, Transportation, and Ripening Techniques
Harvesting: Hand-picked at optimum physiological maturity to avoid bruising.
Grading: Based on size, colour, and freedom from defects.
Packing: Packed in cushioned, ventilated cartons. Like in telescopic fiberboard cartons or CFB boxes
Precooling: Rapid cooling to 0–2°C.
Storage: Cold storage: 0–1°C with 90–95% RH; can last up to 6 months
CA storage for exports. Controlled atmosphere storage (CA) extends shelf life up to 8–10 months
Transportation: Refrigerated vans for transport are essential for long-distance and export markets.
Ripening: Apples are climacteric; they can be ripened off-tree, but are best harvested at optimum maturity for storage.
Use of ethylene (100 ppm) in ripening chambers. Maintain 20–22°C and 85% RH.
Industrial and Export Potential, Agri Export Zones (AEZ), and Industrial Support
Industrial Uses: Fresh fruit, juice, cider, vinegar, jelly, dried slices, and puree.
Export Potential: Major exporters: China, USA, Poland, Italy, France, Chile, New Zealand. India is a net importer but exports to neighbouring countries.
AEZ and Industrial Support: AEZs established in Himachal Pradesh, Jammu & Kashmir, and Uttarakhand for value addition, cold chain, and export promotion. NHB, APEDA, and state horticulture missions support.
Organic Production: Gaining importance, especially for niche markets in the US and EU.