Lychees are a beloved fruit, enjoyed both domestically and internationally. This delicious fruit is also a valuable export commodity. Have you ever wondered how to cultivate lychees for high yields and minimize pests and diseases? Nongnghiepvietnam.org, Vietnam’s leading agricultural website, provides a comprehensive guide to growing and caring for these prized fruit trees.
Lychee Growing Conditions
Lychee trees are perennials, adaptable to various regions from Nghe An and Thanh Hoa northward. They have strong root systems, tolerate drought well, but are susceptible to waterlogging. These trees are not picky about soil and can thrive in various types, from fertile soil and hillsides to acidic soil. However, for optimal yield and quality, lychees need cool, dry weather, especially during budding and flowering.
Popular Lychee Varieties in Vietnam
Vietnam boasts a wide variety of lychee cultivars, each with unique characteristics and advantages. Here are some common varieties:
Sour Lychee
This traditional variety, while historically significant, is less common today due to inconsistent fruit quality, large seeds, and a sour taste.
Nho Lychee
A hybrid variety derived from seeded lychees, Nho lychees are larger and tastier than sour lychees but still inferior to Thieu lychees. They typically ripen after sour lychees and are sparsely cultivated in midland hills.
Phu Ho Lychee
This variety offers several advantages: early ripening (about 5 days before Thieu lychees), large fruit size, high flesh ratio (over 70%), sweet flavor, easy-to-peel skin, and suitability for canning. Phu Ho lychees also tolerate drought and acidic soil well. However, they require low temperatures in November and December for flowering.
Thanh Ha Lychee
Selected and propagated in Thanh Ha, Hai Duong, over a century ago, Thanh Ha lychees are the dominant variety in the northern plains and midlands due to their exceptional yield and quality.
Xuan Dinh Lychee
Similar to Thanh Ha lychees, Xuan Dinh lychees are larger, have a deep red skin, and offer excellent flavor.
Ripe red lychees on a branch, ready for harvest.
Lychee Propagation Techniques
Lychees can be propagated by various methods, including seeding, grafting, and air-layering. Air-layering is the most common and effective method.
Air-Layering
Step 1: Selecting the Mother Tree
Choose healthy, high-yielding mother trees aged 8-15 years with consistently high fruit quality. Select vigorous branches, 1-1.5cm in diameter, growing slightly slanted towards the light.
Step 2: Girdling
Use a sharp knife to remove a 2-3cm ring of bark, scrape clean, and let dry for 3-4 days.
Step 3: Wrapping the Rooting Medium
Wrap the girdled area with a mixture of topsoil, compost, and rice straw, then cover with polyethylene film. Tie tightly below the rooting medium and loosely above.
Step 4: Aftercare
The best time for air-layering is March-April or July-August. After 3 months, when roots have developed, cut the layered branch and plant it in a nursery. After 4-6 months of care, the saplings can be transplanted to the orchard. During this period, ensure adequate watering, especially during the dry season.
Planting and Caring for Lychee Trees
Soil Selection
While lychees are not soil-selective, well-drained soil with a thick topsoil layer is ideal for optimal growth. On hillsides, choose areas with gentle slopes, plant along contour lines, and create terraces to prevent erosion.
Planting Season
Lychees can be planted in spring (March-April) or autumn (August-September).
Planting Density
A spacing of 6m x 4m, with a density of 400 trees/ha, is recommended.
Digging Planting Holes
Dig holes of appropriate size based on soil type:
- Flat, low-lying land: 70-80cm wide, 70cm deep.
- Hillside: 70-80cm wide, 80-100cm deep.
Note: Keep the topsoil separate to use for backfilling.
Basal Fertilization
One month before planting, apply 20-30kg of well-rotted manure, 0.7kg of phosphate fertilizer, grass clippings, and green manure to each hole. Fill to the top and cover with topsoil.
Planting
Dig a small hole, 15-20cm deep, in the center of the planting hole. Place the sapling in the hole and backfill with soil, pressing firmly. Avoid stepping on the root ball. After planting, stake the tree for support and water immediately.
Lychee Tree Care
Watering
After planting, water regularly to keep the soil moist and promote root establishment and recovery.
Fertilization
- First 3 years: Use diluted liquid fertilizer.
- From the 4th year onwards: Apply 40-50kg of well-rotted manure + 1.5kg of urea + 2kg of phosphate + 0.7kg of potassium per tree, divided into 3 applications:
- Application 1 (October-November): 100% manure + 40% urea + 40% phosphate.
- Application 2 (December-January): Apply when flower buds differentiate, 40% urea + 30% phosphate + 40% potassium.
- Application 3 (March-April): Apply the remaining fertilizer.
Pruning and Shaping
Start shaping the tree in the nursery, aiming for a single main trunk and 3 branches oriented in different directions. Annually, prune suckers, water sprouts, and diseased branches. Remove winter shoots and focus on caring for autumn and spring shoots. Remove the first fruit crop (king fruit) to allow the tree to focus on vegetative growth.
Pest and Disease Control
Common lychee pests and diseases include:
- Stink Bugs: Prevalent in March-April, causing fruit drop. Use pesticides like Drotox, Bi 58, or Dipterex. Alternatively, shake the trees at night to dislodge the bugs for collection and disposal.
- Stem Borers: Adult borers lay eggs on branches, and the larvae bore into the stems, causing breakage and drying. Use a wire or thorn to kill the larvae or inject diluted Padan 15WP into the borer holes.
- Mites: Mites suck sap from the underside of leaves, causing red fuzz. Remove and burn infested leaves or spray with Ortors or Bi 58.
A farmer spraying pesticide on lychee trees for pest and disease control.
Lychee Preservation and Processing
Harvested lychees can be stored in polyethylene bags at 7°C for about 5 weeks. However, preserving fresh lychees is generally challenging. Common processing methods include drying and candying, which extend shelf life and increase economic value.
Conclusion
Nongnghiepvietnam.org hopes this comprehensive guide provides valuable insights into lychee cultivation and care, empowering you to successfully grow and manage this valuable fruit tree. Best of luck!
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