Longan Farming Profit Per Acre

Longan Farming 

Longan (Dimocarpus longan) is a major tropical/subtropical fruit tree valued for its sweet, juicy aril. Longan farming profit per acre demonstrates compelling long-term viability, with a 30-year net profit of NRs. 25,524,800 against a total investment of NRs. 2,279,200 (including NRs. 104,200 initial and NRs. 2,175,000 maintenance costs).

Total income reaches NRs. 27,804,000, yielding a robust Benefit-Cost Ratio of 12.2:1 and an average annual profit of NRs. 850,827. Critical insights highlight a 6-year payback period, 85% of profits (NRs. 21.65 million) concentrated in Years 8–25, and significant price sensitivity (+25% price boosts post-Year 16 income by NRs. 462,000/year). Note that Years 1–7 require a NRs. 254,200 capital buffer due to maintenance costs consuming 35–89% of early income.

Land Preparation

Land preparation begins with clearing the field by removing vegetation, stumps, and debris to ensure a clean planting area. The land is then leveled or gently contoured—especially on slopes under 15 degrees—to prevent erosion and support effective irrigation and drainage.

Deep plowing to a depth of 50–60 cm breaks compact layers, enhances aeration, and promotes root growth, followed by harrowing to create a finer soil texture. Proper drainage is essential, especially in waterlogged or high-rainfall areas, often requiring ditches or trenches and the use of raised beds. Finally, individual planting basins or slightly elevated platforms about 1–2 feet in diameter are prepared for each tree, incorporating well-decomposed organic matter to improve soil fertility and structure.

Soil Type

Longan grows best in deep, well-drained, and fertile soils such as sandy loam, loam, or clay loam with good structure and sufficient organic matter. Proper drainage is crucial, as longan roots are highly sensitive to waterlogging, which can cause root rot and tree mortality. The ideal soil pH ranges from 5.5 to 6.5, as this slightly acidic to neutral range optimizes nutrient availability.

Avoid poorly drained heavy clay soils, saline or highly alkaline soils (pH above 7.5), and shallow soils over bedrock or hardpan. Prior to planting, a comprehensive soil test should be conducted to assess pH, nutrient status, and organic matter content, with necessary amendments applied accordingly.

Climatic Requirements

Major Cultivars

When selecting longan cultivars, prioritize those that have demonstrated strong performance in your specific region and microclimate. Focus on varieties that are well-adapted to local climatic conditions, including temperature extremes, humidity, and rainfall patterns.

Choose cultivars known for superior fruit quality—large fruit size, high sweetness, good flesh-to-seed ratio, and desirable texture. High yield potential and resistance to prevalent pests and diseases are also essential to ensure consistent productivity and reduce input costs.

Consider the flowering season to match your management schedule and avoid adverse weather during critical stages. Lastly, align your choice with market preferences to ensure good demand, pricing, and post-harvest value.

Seedling rate per acre

Longan is predominantly propagated vegetatively—through air-layering (marcotting), grafting, or budding—to maintain true-to-type characteristics, promote earlier fruiting within 3 to 5 years, and ensure high fruit quality. Depending on the planting distance and layout, an acre can accommodate approximately 65 to 100 plants.

Planting

a). Planting Season

Longan can be planted from June to October, provided proper irrigation is available during dry spells. The best time to plant longan is at the onset of the rainy season, as the natural moisture aids in seedling establishment and reduces transplant shock.

b). Spacing

A commonly recommended spacing is 8 meters between rows and 6 meters between plants within a row.

c). Pit Preparation
Pit preparation for longan planting should begin at least 3 to 4 weeks before transplanting to allow the soil to weather. Each pit should measure approximately 60 cm x 60 cm x 60 cm.

The excavated topsoil should be thoroughly mixed with 10–15 kg of well-rotted farmyard manure or compost, 500 g of Single Super Phosphate (SSP), and 200–300 g of Muriate of Potash (MOP); adding beneficial mycorrhizal fungi is recommended if available. The pit should then be refilled with this enriched mixture, slightly mounded above ground level to compensate for settling.

d). Planting Method
To plant longan, dig a tiny hole big enough to accommodate the root ball in the middle of the pit. Place the plant in the hole, maintaining the graft union 10 to 15 cm above the ground, after carefully removing it from its container.

Create a basin to hold water, backfill with soil, and compact around the roots. Give young trees plenty of water, stake them for stability, and mulch the base of the tree rather than the trunk to keep moisture in and keep weeds out.

e). Number of Plants per Acre

Based on a spacing of 8 meters by 6 meters, approximately 84 longan plants can be accommodated per acre.

Intercropping

Intercropping in longan orchards is highly recommended, especially during the first 3–4 years when the trees are still small and provide minimal shade, allowing optimal use of space. This practice offers several benefits, including early income generation, weed suppression, and improved soil fertility—particularly when legumes are used.

Suitable intercrops include short-duration, shallow-rooted, and non-climbing species that do not compete heavily with young longan trees for water and nutrients. Examples include vegetables like bush beans, peas, radishes, leafy greens, peppers, and eggplant; legumes such as cowpea and mung bean; root crops like ginger and turmeric (which benefit from partial shade later); and pineapple, which serves as an effective ground cover.

Irrigation

Irrigation is essential in longan farming, particularly during establishment (first 1–2 years), flowering, fruit set, and final fruit development, as water stress during these stages can lead to flower and fruit drop. Mature trees need regular deep watering, with frequency depending on soil type, temperature, and rainfall—sandy soils requiring more frequent irrigation.

Drip irrigation is highly efficient, delivering water directly to the root zone, minimizing weeds and diseases, and allowing fertigation. Basin irrigation and micro-sprinklers are also used, though basins need level land and careful water management. Overhead sprinklers should be avoided during flowering to prevent pollen loss and fungal issues.

Post-harvest, reduce watering slightly to allow trees to rest, resuming normal irrigation with new growth. Mulching helps conserve moisture and lowers irrigation needs.

Fertilizer and Manure

Fertilizers should be applied evenly in a ring around the tree, beneath the outer canopy, and either lightly mixed into the soil or watered in to aid absorption. Avoid placing fertilizer near the trunk to prevent potential damage. For accurate nutrient application, always refer to the most recent soil test report.

Weed Control

Since weeds compete for nutrients and water and can harbor pests and illnesses, weed control is crucial in longan cultivation, particularly in the early stages. Mulching the area around the drip line with 8–15 cm of organic material, such as wood chips, compost, or straw, efficiently reduces weeds and enhances soil health.

Both manual weeding and mechanical hoeing are beneficial, but they should be done carefully to prevent damaging the roots. Herbicides should be applied with caution: Glyphosate (1–2 mL/L) as a directed spray outside the drip line for post-emergent weeds, and Diuron (600 g/acre) or Oxyfluorfen (200–400 g/acre) for pre-emergent management. In addition to reducing weeds, growing cover crops in between rows improves sustainability.

Intercultural Operations

Training
Training in longan farming involves shaping young trees to develop a strong and balanced framework that supports future growth and fruit production. Typically, the central leader system is used, where one main trunk is encouraged with 3–4 well-spaced lateral branches. This structure allows for good light distribution and airflow within the canopy. Early training reduces the need for heavy pruning later and helps create a manageable tree size for harvesting and maintenance.

Pruning
Pruning is carried out regularly in longan cultivation to remove dead, diseased, or overcrowded branches and to control tree height and shape. After harvesting, pruning stimulates the growth of new shoots, which is crucial since longan trees bear fruit on the current season’s growth. By maintaining an open canopy, pruning improves sunlight exposure, enhances air circulation, and reduces the risk of pests and diseases, ultimately contributing to better fruit yield and quality.

Flowering and Fruit Management

Flowering Induction

Flowering induction is essential in regions where winters are not consistently cool or dry. Cultural practices such as controlling water stress during late fall or winter and root pruning can stimulate flowering. Chemically, foliar application of Potassium Chlorate (KClO₃) is highly effective and widely used, though it must be applied carefully following local regulations and cultivar-specific rates. In some cases, Paclobutrazol may also be used, though it is less common for longan.

Pollination

Longan trees rely primarily on insect pollination, with bees and flies playing a major role. Ensuring the presence of pollinators during the flowering period is crucial. Avoid using insecticides harmful to pollinators during bloom. In some cultivars, cross-pollination can enhance fruit set and improve overall productivity.

Fruit Set and Thinning

Natural fruit drops are common after fruit set, but excessive fruit set can result in smaller fruit and may even cause branch breakage. Thinning is necessary to promote the development of large, high-quality fruits and to reduce tree stress, helping prevent biennial bearing.

Thinning should be done 4–6 weeks after fruit set by removing entire clusters that are small, damaged, or poorly positioned. Within the remaining clusters, remove 30–50% of the fruits, especially those that are misshapen, small, or too densely packed, leaving 1–2 cm spacing between fruits.

Fruit Bagging

In some countries like Taiwan and China, fruit bagging is practiced to protect fruits from pests and environmental damage. Paper bags are placed over clusters 6–8 weeks before harvest to guard against fruit flies, borers, birds, sunburn, and wind scars. This technique significantly boosts the marketability and quality of the harvested fruit.

Propping

Heavy fruit loads can strain or break branches. To prevent this, support should be provided using bamboo poles or Y-shaped frames under the heavily laden limbs. Propping helps maintain tree structure and prevents loss due to breakage.

Pest and Disease Management

Common Pests

a). Fruit Flies

Fruit flies (Bactrocera spp.) are a major pest in longan farming, causing internal fruit damage and early fruit drop. Effective control involves an integrated approach. Maintain field sanitation by removing fallen and infested fruits. Use methyl eugenol traps to monitor and reduce adult populations.

Apply bait sprays made of protein hydrolysate and Malathion (1.5–2 mL/L) to attract and kill flies. For broader protection, use Spinosad 45% SC at 0.3 mL/L as a cover spray during peak activity. Fruit bagging 6–8 weeks before harvest provides a physical barrier against egg-laying. Combining these methods ensures effective and sustainable fruit fly management.

b). Longan Erinose Mite

Longan erinose mite causes felt-like galls on young leaves, reducing tree vigor and photosynthesis. Early control is essential. Prune and destroy infested leaves to limit spread. For chemical control, apply wettable sulphur (80% WP) at 2 g/L of water.

In severe cases, use miticides like Propargite 57% EC at 2 mL/L or Fenpyroximate 5% EC at 1 mL/L, ensuring good coverage, especially on leaf undersides. Repeat sprays may be needed at 10–14 day intervals. Combining cultural practices with timely sprays ensures effective management.

c). Stink Bugs/Shield Bugs

tink bugs or shield bugs are pests that pierce developing longan fruits, leading to blemishes, deformation, and premature fruit drop, which significantly reduces market value. Regular monitoring during fruit development is essential to detect their presence early.

When populations reach damaging levels, insecticidal control may be required. Effective options include Imidacloprid 17.8% SL at 0.3 mL/L or Thiamethoxam 25% WG at 0.25 g/L, applied as a foliar spray. These systemic insecticides target the bugs while minimizing harm to beneficial insects when used properly.

To ensure effectiveness, avoid spraying during flowering to protect pollinators and always follow label instructions for safety and timing.

d). Longan Borers/Stem Borers

Longan borers or stem borers are destructive pests whose larvae tunnel into branches and trunks, weakening the tree and potentially causing dieback or death. Effective management involves early detection, followed by pruning and destroying infested branches to remove active larvae.

For active infestations, inject insecticides such as Chlorpyrifos 20% EC at 5 mL/L or Quinalphos 25% EC at 2 mL/L directly into borer holes, then seal the openings with mud or wax to retain the chemical. Maintaining overall tree vigor through proper nutrition and irrigation also helps trees resist borer attacks. Regular monitoring is key to preventing widespread damage.

e). Scales and Mealybugs

Scales and mealybugs are sap-sucking pests that weaken longan trees by feeding on plant juices and excreting honeydew, which encourages the growth of sooty mold and reduces photosynthesis. Early infestations can be managed using horticultural oils (2%) or insecticidal soaps to smother the pests.

For severe infestations, apply systemic insecticides such as Imidacloprid 17.8% SL at 0.3 mL/L or Thiamethoxam 25% WG at 0.25 g/L as foliar sprays. Ensure thorough coverage of leaf undersides and stems. Regular monitoring and maintaining tree health are essential for long-term control.

f). Birds

Birds can cause significant damage to ripe longan fruits by pecking and feeding, leading to yield loss and reduced fruit quality. To protect the crop, bird netting over trees or orchard sections is the most effective physical barrier. Alternatively, scare devices such as reflective tape, sound cannons, or predator decoys can help deter birds, though their effectiveness may decrease over time as birds adapt. A combination of methods and rotating deterrents is often necessary for sustained protection.

Common Diseases

a). Algal Spot/Red Rust

Algal spot, also known as red rust, is a common disease in longan caused by parasitic algae, appearing as greenish-orange fuzzy patches on leaves and young stems. This disease reduces photosynthesis, weakens tree vigor, and can spread rapidly under warm, humid conditions. Effective management involves improving air circulation through regular pruning and canopy thinning to reduce humidity within the tree.

Chemically, it can be controlled using copper-based fungicides such as Copper Oxychloride 50% WP at 2.5 g/L or Bordeaux mixture (1%), applied as a foliar spray. Repeat applications may be necessary at 10–15 day intervals during high-risk periods. Timely intervention and good orchard hygiene help prevent severe outbreaks.

b). Anthracnose

Anthracnose is a fungal disease in longan causing blossom blight, fruit rot, and leaf spots, especially in wet conditions. Control involves pruning to improve airflow and avoiding overhead irrigation to reduce moisture. Fungicides like Copper Oxychloride 50% WP (2.5 g/L), Mancozeb 75% WP (2–2.5 g/L), or Azoxystrobin 25% SC (1 mL/L) can be applied every 7–14 days during wet weather. Combining timely sprays with good cultural practices helps minimize damage and protect yield.

c). Phytophthora Root Rot & Collar Rot

Phytophthora root rot and collar rot are serious diseases in longan, especially in waterlogged soils, causing yellowing leaves, dieback, and root decay. Prevention is crucial and involves ensuring excellent soil drainage, avoiding deep planting, and using tolerant rootstocks when available.

Preventative treatments with phosphonate fungicides, such as Phosphorous acid at 2.5 mL/L, applied as soil drenches or foliar sprays, help protect trees from infection. Proper site selection and management are key to reducing disease risk.

d). Pink Disease

Pink disease in longan is identified by pink fungal growth on branches, leading to dieback and weakening of the tree. To manage this disease, prune infected branches thoroughly, cutting well below the visible canker to remove all infected tissue. After pruning, apply copper-based fungicides such as Copper Oxychloride 50% WP at 2.5 g/L to the affected areas and surrounding healthy bark to prevent further spread. Regular monitoring and prompt treatment help minimize damage and maintain tree health.

e). Sooty Mold

Sooty mold appears as a black fungal coating on longan leaves and stems, growing on the honeydew secreted by sap-sucking insects like scales, aphids, and mealybugs. While the mold itself doesn’t infect the plant, it blocks sunlight and reduces photosynthesis, weakening the tree.

Effective control focuses on managing the insect pests through treatments like horticultural oils (2%), insecticidal soaps, or systemic insecticides such as Imidacloprid 17.8% SL at 0.3 mL/L. Reducing these pests will help prevent sooty mold buildup and improve overall tree health.

Harvesting

Longan is prone to biennial bearing, where a heavy crop one year is followed by a lighter one the next; however, consistent management practices—especially careful post-harvest care, balanced nutrition, and timely thinning—can help reduce this irregularity and promote more stable yields.

Harvesting Method
Harvest longan by carefully clipping entire fruit clusters (panicles) from the tree using sharp secateurs or clippers. Ensure a short stem (peduncle) remains attached to the cluster. Avoid pulling or twisting fruit off the tree to prevent damage.

Handling
Handle harvested clusters gently to prevent bruising and skin abrasion. Place them carefully into field containers such as baskets or crates, avoiding overfilling to reduce pressure and damage.

Harvest Timing
Harvest early in the morning when temperatures are cooler to maintain fruit quality. Avoid harvesting when the fruit is wet from rain or dew to minimize the risk of disease.

Post-Harvest Management
Immediately move harvested fruit to a shaded area and pre-cool if possible. Sort the fruit to remove any damaged or diseased pieces before packing. Longan has a relatively short shelf life of 2–3 weeks when stored at 4–6°C with high humidity, so proper handling and storage are essential for maintaining quality.

Yield

Mature trees (8 years and older) reach peak yields with good management, averaging about 80 kg per tree, which equates to approximately 6,720 kg per acre with 84 trees planted per acre.

Cost of Investment per Acre for Longan Farming

Annual Maintenance Cost per Acre

From the second year onward, longan farming requires an estimated annual maintenance cost of NRs. 75,000 per acre, which covers essential activities to sustain tree health and maximize yield.

This includes the cost of fertilizers and organic manure, irrigation management, weed control (both manual and chemical), pest and disease management using approved insecticides and fungicides, pruning and training operations, labor charges, and general upkeep of the orchard.

Timely and consistent investment in these areas is crucial for ensuring good fruit quality, preventing alternate bearing, and maintaining long-term orchard productivity.

Income from Longan Farming Per Acre

Analysis of Longan Farming Profit Per Acre

Total investment costs over 30 years amount to NRs. 2,279,200 (NRs. 104,200 initials + NRs. 2,175,000 maintenance), yielding NRs. 27,804,000 in total income and a net profit of NRs. 25,524,800. Key metrics confirm strong viability: a 12.2:1 Benefit-Cost Ratio, 6-year payback period (breakeven achieved in Year 6), and NRs. 850,827 average annual profit.

Critical insights reveal that 85% of profits (NRs. 21.65 million) come from peak Years 8–25, though Years 1–7 require NRs. 254,200 capital resilience to offset negative cash flow. Price increases after Year 16 significantly boost returns (e.g., +25% price = +NRs. 462,000/year), while maintenance costs consume 35–89% of annual income until maturity, demanding careful risk mitigation.

Sources

Mani, Gopal & Singh, Omveer & Rai, Ratna. (2024). longan (Dimocarpus longan Lour.).

Food and Agriculture Organization (FAO)

Indian Council of Agricultural Research (ICAR)

University of California Agriculture & Natural Resources (UC ANR)

Nepal Agricultural Research Council (NARC)