Introduction
Litchi (Litchi chinensis), a tropical and subtropical fruit, is esteemed for its juicy, aromatic arils and nutritional value. In India, litchi cultivation is predominantly concentrated in Bihar, West Bengal, Uttar Pradesh, and parts of Uttarakhand, with Bihar accounting for approximately 75% of the total production. The fruit is consumed fresh and is also processed into juices, jellies, and canned products.
Soil and Climate
Soil Requirements:
Litchi thrives in deep, well-drained loamy soils rich in organic matter. The ideal soil pH ranges from 5.5 to 7.0. Waterlogged or saline soils are unsuitable for litchi cultivation.
Climatic Conditions:
Litchi prefers a humid subtropical climate, free from frost during winter and dry heat in summer. Optimal temperature for growth is around 30°C. Temperatures above 40.5°C in summer and below freezing point in winter can be detrimental to the crop.
Varieties
Several litchi varieties are cultivated in India, each with distinct characteristics:
- Shahi: Early maturing, juicy, and sweet variety, popular in Bihar.
- China: Late maturing, large-sized fruits with good shelf life.
- Bombai: Medium-sized fruits with excellent flavor, grown in West Bengal.
- Dehradun: Medium-sized, sweet fruits, suitable for northern regions.
- Rose Scented: Distinct aroma, medium-sized fruits, cultivated in Punjab.
- Late Seedless: Seedless variety with extended shelf life.
- Early Seedless: Early maturing, seedless variety with good taste.
Propagation and Rootstock
Propagation Methods:
Litchi is primarily propagated through air layering (gootee), which involves inducing roots on a branch while still attached to the parent plant. The ideal time for air layering is during the rainy season (June to September). The rooted layers are detached after 60-70 days and planted in nurseries for establishment before field planting.
Rootstock:
Litchi is not commonly grafted; hence, rootstock selection is not a standard practice. However, using healthy, disease-free mother plants for propagation ensures vigorous growth and productivity.
Planting Density, Planting Time, Planting Method
Planting Time:
The best time for planting litchi is during the monsoon season (August to September). In areas with assured irrigation, planting can also be done in spring (February to March).
Planting Density:
Traditional spacing is 10 × 10 meters, accommodating 100 trees per hectare. High-density planting with spacing of 8 × 8 meters or 8 × 6 meters can be adopted, depending on the variety and management practices.
Planting Method:
Pits of 1 × 1 × 1 meter are dug and left open for 15-20 days. Each pit is filled with a mixture of topsoil, 25 kg of well-decomposed farmyard manure (FYM), 2 kg bone meal, and 300 g muriate of potash. Incorporating soil from an old litchi orchard can introduce beneficial mycorrhizal fungi. After planting, immediate irrigation is essential for soil settlement.
Irrigation
Young litchi plants require frequent irrigation, especially during dry periods. Mature trees need irrigation at critical stages:
- Winter: Two irrigations at intervals of 45–60 days.
- Summer (March to June): Fortnightly irrigation is crucial during fruit development to prevent fruit cracking and drop.
Basin or ring irrigation systems are commonly used. Drip irrigation is recommended for efficient water use and better plant growth.
Manure and Fertilizers
Nutrient requirements vary with the age of the tree:
| Age (Years) | FYM (kg/tree) | CAN (kg/tree) | Super Phosphate (kg/tree) | Muriate of Potash (kg/tree) |
|---|---|---|---|---|
| 1–3 | 10–20 | 0.3–1.0 | 0.2–0.6 | 0.05–0.15 |
| 4–6 | 25–40 | 1.0–2.0 | 0.75–1.25 | 0.20–0.30 |
| 7–10 | 40–50 | 2.0–3.0 | 1.50–2.0 | 0.35–0.45 |
| Above 10 | 60 | 3.5 | 2.25 | 0.60 |
FYM, phosphorus, and potassium should be applied once a year in autumn. Nitrogen is applied twice a year: once in January–February and again in September–October. Zinc deficiency, indicated by bronzing of leaves, can be corrected by applying 4 kg zinc sulphate and 2 kg hydrated lime per hectare.
Intercultural Operations
Weed Control:
Regular weeding is essential, especially during the initial years. Mulching with organic materials like straw helps suppress weeds and conserve soil moisture.
Intercropping:
Intercropping is feasible during the first 3–4 years. Suitable intercrops include:
- Summer & Kharif Season: Pumpkin, cucumber, ridge gourd, bitter gourd, moong, cowpea.
- Winter Season: Radish, beet, turnip, cauliflower, peas, beans, gram, turmeric.
Training and Pruning
Training:
Young litchi plants should be trained to develop a strong framework of 4–6 main branches. Remove side branches until the saplings reach about one meter in height, then allow selected branches to grow.
Pruning:
Pruning is generally minimal, limited to removing dead, diseased, or crossing branches. During harvesting, removing the fruit-bearing shoots serves as a form of pruning, promoting new growth.
Major Pests
Common pests affecting litchi include:
- Litchi Mite (Aceria litchii): Causes brown velvety galls on leaves, leading to leaf distortion.
- Shoot Borer: Damages new shoots, affecting growth.
- Bark Eating Caterpillar (Indarbela tetraonis): Larvae bore into bark, weakening the tree.
Management:
- Spray appropriate insecticides like Cypermethrin (0.01%) during flushing periods.
- Remove and destroy affected plant parts.
- Maintain orchard hygiene to reduce pest incidence.
Major Diseases
Litchi is relatively free from major fungal diseases. However, some issues include:
- Fruit Rot: Caused by Aspergillus species, leading to fruit decay.
- Leaf Spot: Caused by Helminthosporium species, resulting in leaf lesions.
Management:
- Apply recommended fungicides immediately after symptom appearance.
- Avoid fungicide application at least 20 days before harvesting.
Harvesting
Litchi trees propagated through air layering start bearing fruits in 5–6 years. Flowering occurs in January–February, with fruits maturing in May–June. Indicators of fruit maturity include:
- Flattening of tubercles on the fruit surface.
- Smoothness of the epicarp.
- Color change from green to pink or red.
Fruits are harvested in bunches along with a portion of the branch and a few leaves to improve shelf life and reduce post-harvest losses.
Yield
A mature litchi tree yields approximately 40–100 kg of fruits annually, depending on variety, age, and management practices. Proper cultural practices, pest and disease management, and nutrient application are essential4