Introduction:
- Grape is an important sub-tropical fruit crop in India with the highest average productivity in the world (16.95 t/ha).
- Genus Vitis is sub-divided into two sub-genera: Muscadinia (2n=40) and Euvitis (2n=38).
- Vitis vinifera is the most popular cultivated species; it has forked tendrils and shiny leaves.
- Common rootstocks for resistance include: V. riparia, V. rupestris, V. berlandieri, V. candicans, V. rufotomentosa, and V. solanis.
Uses:
- Table Purpose: For fresh consumption. Varieties: Muscat Hamburg, Cardinal, Perlette, Thompson Seedless, Tokay, Concord, Anab-e-Shahi, Pusa Seedless, etc.
- Raisin Making: Requires seedlessness, high sugar, soft texture. Varieties: Thompson Seedless, Seedless Sultana, Red Corinth, Cape Currant, Black Monukka.
- Juice Making: Should retain natural flavour. Varieties: Concord (USA), White Riesling, Chasselas Dore (Europe), Aramonand, Carignan (France).
- Wine Making: Table wines (<14 alcohol="" dessert="" wines="">14%). Quality depends on sugar-acid ratio, acidity, tannins. Varieties: Chardonnay, Cabernet Sauvignon, Muscat Blanc, etc.
- Canning: Seedless types preferred. Varieties: Thompson Seedless, Canner.
Origin and Distribution:
- Origin: Asia Minor (between Caspian & Black Sea).
- Major producers: Spain, Italy, France.
- India: 63,000 ha area, 16.67 lakh tonnes production.
- States: Maharashtra, Karnataka, Tamil Nadu, Punjab, Andhra Pradesh, Haryana, Uttar Pradesh, Madhya Pradesh.
Soil and Climate:
- Best soil: Sandy loam, fertile, well-drained, pH 6.5-7.5.
- Unsuitable: Heavy, shallow, ill-drained, alkaline soils.
- Climate: Warm to hot dry summers and cool winters.
- Rain during flowering is harmful; optimum temperature: 28-32°C.
Popular Cultivars:
- Coloured Seeded: Bangalore Blue, Kishmish Charni, Black Champa.
- Coloured Seedless: Beauty Seedless, Flame Seedless.
- White Seeded: Anab-e-Shahi, Dilkush, Cheema Sahebi.
- White Seedless: Perlette, Pusa Seedless, Thompson Seedless, Tas-e-Ganesh, Sonaka, Arkavati, Delight, Homorod.
Propagation:
- Hardwood stem cuttings; treat with IBA for rooting.
- Single bud cuttings can root at 18-20°C.
- Chip budding/grafting used with resistant rootstocks.
Resistant Rootstocks:
- Phylloxera: Riparia Gloire, St. George, 4x2, 1202, 99.
- Nematode: Dogridge, Salt Creek, 1613-1616, Telecki 5A, Solonis 1616.
Land Preparation:
- Soil Solarization: Use moist soil, bury plastic edges, 4-6 weeks in summer using clear plastic.
- Mulching: Use straw, sawdust, hay, etc. Organic mulches need to be 4+ inches thick.
- Weed Management: Reduce soil seed bank before planting. Use fallow irrigation-tillage-drying cycles. Avoid cover crops under vine row.
Herbicides:
- Organic herbicides include soap-based (Scythe), clove oil (Matran 2), acetic acid (All-Down).
- Apply carefully to avoid damaging grape vines; require surfactants and multiple applications.
Planting:
- Plant 1 m³ pits with manure mix.
- Use one-year-old plants; spacing 1.2-5.0 m x 2.5-6.6 m (maximum for pandal system).
- Planting time: Jan–Feb (rooted); October (unrooted).
Manuring:
- Average uptake: 40-60 kg N, 10-15 kg P, 50-70 kg K/ha.
- Anab-e-Shahi: N – 150 kg/ha, P – 120 kg/ha, K – 300 kg/ha.
- Thompson Seedless: N – 300 kg/ha, P – 500 kg/ha, K – 1000 kg/ha.
- North India: N – 700 kg/ha, P – 1200 kg/ha, K – 1000 kg/ha.
- Start fertilizer from 1st month after pruning.
- Micronutrients (Fe, Zn, B, Mn) as foliar spray at pre-blossom stage.
Irrigation:
- Less water needed during bud formation; more during berry development.
- Reduced irrigation during ripening improves fruit quality.
- Drip irrigation preferred. Water requirement (liters/day/ha):
- 0–40 days: 48,000–60,000
- 41–100 days: 24,000–32,000
- 101+ days: 15,000–20,000
- Post winter pruning: 20,000–60,000 depending on stage
Interculture:
- Grow Daincha or Sunhemp as intercrop.
- Weeds can be controlled using Paraquat @ 7.5 L/ha post-emergence.
BOWER SYSTEM
Grapes have traditionally been trained using overhead arbour or Pandal systems in Tamil Nadu since their introduction. Although the original bowers were quite low and often relied on wooden stakes—which had limitations—modern growers have started adopting stronger materials like cement, stone pillars, or G.I. tubes.
The canopy above is usually constructed with thin bamboo (2 to 2.5 cm) or galvanized iron (G.I.) wires ranging from 8 to 16 gauge. Cross connections between pillars are made of sturdy materials such as thick bamboo, trek-wood, palmyra rafters, or metal pipes. These wires are spaced in a grid of either 30 x 30 cm or 30 x 45 cm.
Grape cuttings planted in the field typically grow up to 180 cm within three months. Once this height is achieved, the top is pinched around 15 cm below the bower. This encourages 2 to 4 lateral shoots, which are then trained in different directions to form arms. These arms extend to the edge of the pandal and are then tipped. Secondary branches emerge on these arms, spaced 45 cm apart on alternate sides. These secondaries produce tertiaries, from which fruit-bearing canes and bunches develop.
Some farmers opt for a single-arm structure with secondaries spaced at convenient distances, while others allow uncontrolled arm growth, which often leads to poorly structured vines with excessive wood.
Advantages of the Pandal System:
- India’s climate enables vigorous vine growth and frequent harvests every 4.5 to 5 months.
- Ample sunlight ensures better fruit development.
- Improved effectiveness of plant protection, especially against mildew.
- Studies at Coimbatore and Periyakulam showed the Pandal system performs well with Anab-e-Shahi and Pachadraksha varieties.
- More shoots per vine and per acre were noted in Anab-e-Shahi under the Pandal system.
- The ratio of healthy to weak shoots is better in the Pandal and signal stake systems compared to the Kniffin system.
- Higher vine vigor, as measured by pruning weight per acre, was observed in the Pandal system.
- The Pandal system produced over three times more fruiting canes per vine than other systems.
PRUNING
Grapevines are vigorous climbers and require proper pruning for optimal fruit production. In North India, pruning is done once in January. In contrast, South India sees two pruning seasons—once in summer and again in winter.
Summer Pruning:Conducted during March-April in Andhra Pradesh and Karnataka, and in July in Tamil Nadu, this pruning involves cutting canes back to 1 or 2 buds to encourage fresh vegetative growth. It is known as growth or back pruning.
Winter Pruning:This is carried out in late November in Andhra Pradesh and Maharashtra, mid-October around Bangalore, and December in Tamil Nadu. Mature canes around 6 months old are pruned, and immature shoots and foliage are removed. The pruning level varies by variety:
- Anab-e-Shahi, Bhokri: 5 buds
- Thompson Seedless: 10 buds
- Bangalore Blue: 4 buds
- Gulabi: 9 buds
Objectives of Pruning:
- Maintain manageable vine size by reducing old wood.
- Promote fruit-bearing shoots at specific positions.
- Ensure adequate sunlight reaches fruiting branches.
- Control excessive vegetative growth.
Key Terminologies:
- Cane: Mature shoot from the previous year that produces new shoots.
- Shoot: Young green stem of the current season bearing grape clusters.
- Spur: A remaining cane piece after pruning.
- Fruiting Spur: Cane with 3-4 buds that bear bunches.
- Foundation Spur: A well-ripened cane that forms the base for future growth.
- Trunk: Main stem of the grapevine.
- Long Spur: Shoot with over 5 buds (25-30 cm in length).
- Medium Spur: Cane trimmed to 3-5 buds.
HARVESTING AND YIELD
Grapes are non-climacteric and should be harvested at full maturity, determined by accumulated degree days. Early varieties require 1600–2000 degree days, while late ones may need over 3000.
Undeveloped berries or "shot berries" are sweet but undesirable for commercial yield. AVG (2-Aminoethyl Vinyl Glycine) at 50–300 ppm applied 1–3 weeks before anthesis improves berry set. Cluster thinning also enhances fruit quality. A spacing of 3m x 3m and maintaining 60–70 clusters per vine is ideal.
Girdling the shoot a week after bloom helps improve berry set, size, and ripening. Application of GA (40 ppm) and Ethrel (250 ppm) enhances color and yield. Proper canopy management also improves grape quality and output.
Grapevines begin yielding from the 2nd or 3rd year and can remain productive for over 20–25 years. Average yields are 25–30 tonnes/ha, with good practices increasing this to 60–75 tonnes/ha.
Grapes are often packed in corrugated fibreboard boxes with "Grape Guard" liners that extend shelf life. Controlled atmosphere storage with 15–25% CO₂ at 0–1°C allows storage for 7–12 weeks.
Fruiting Bud Levels in Varieties:
- Bangalore Blue: 3–5 buds
- Bhokri: 3–4 buds
- Anab-e-Shahi: 6–8 buds
- Cheemasabebi: 5–8 buds
- Pusa Seedless, Kishmish Charmi, Gulabi: 10–12 buds
Post-Harvest Management
Pests:
- Flea beetles – Spray Malathion or Carbaryl
- Thrips – Use Malathion, 0.5 ml Phosphomidon, or 1 ml Monocrotophos per litre
- Chaffer beetles – Apply insecticide dust in evenings
- Mealy bugs – Spray Dichlorvos
- Scales – Manage with appropriate insecticides
- Nematodes – Use resistant rootstocks
Diseases:
- Anthracnose – Remove infected parts, spray BM, Benlate, Bavistin, or Ziram
- Downy mildew – Apply BM or Mancozeb (2.5 gm/litre)
- Powdery mildew – Dust or spray Sulphur or Neem-based products
Physiological Disorders:
- Blossom end rot – Caused by calcium deficiency
- Interveinal chlorosis – Due to Mn, Zn, or Fe deficiency (use 0.2% solution)
- Stalk necrosis – Linked to calcium deficiency
- Bud/flower/berry drop – Managed by girdling, Ethrel (500 ppm), NAA (100 ppm), Benzyl adenine (200 ppm), and 4-CPA (20 ppm)
- Bud killing – Result of excessive nitrogen application
- Hen & Chicken disorder – Due to boron deficiency