Decision No. 3087/QD-BNN-TCLN Issuing Temporary Technical Guidelines for Macadamia Propagation, Planting, Care, Harvesting Fruit, and Processing Seeds

Pursuant to …;

BIssuing temporary technical guidance on macadamia seedling propagation, planting, care, fruit harvesting, and seed processing

 

THE MINISTER OF AGRICULTURE AND RURAL DEVELOPMENT

Pursuant to Decree No. 119/2013/ND-CP dated November 26, 2013 of the Government stipulating the functions, tasks, powers, and organizational structure of the Ministry of Agriculture and Rural Development;

Considering the proposal of the General Director of the Forest Protection Department,

Pursuant to …;

Clause 4 of Article 6This Decision promulgates the Temporary Technical Guidance on Macadamia Seedling Propagation, Planting, Care, Fruit Harvesting, and Seed Processing.

12/2025/TT-BNNMT dated June 19, 2025 issued by the Minister of Agriculture and EnvironmentThis Decision shall take effect from the date of signing.

Article 3. The Heads of the Ministry's Office, the General Director of the Forest Protection Department, the Heads of the Science and Technology and Environment Department, the Directors of Provincial Departments of Agriculture and Rural Development under the Central Government, the Heads of relevant agencies, organizations, and individuals are responsible for implementing this Decision./.

 

Technical guidance on macadamia seedling propagation, planting, care, fruit harvesting, and seed processing

(Issued together with Decision No. 3087/QD-BNN-TCLN dated August 4, 2015 of the Ministry of Agriculture and Rural Development)

I. GENERAL INTRODUCTION

1. Macadamia is a common name for nine species belonging to the genus Macadamia, family Proteaceae. Among them, two species have commercial value: Macadamia integrifolia Maiden & Betche and Macadamia tetraphylla L. Johnson, both native to the coastal regions of southeastern Queensland and northeastern New South Wales, Australia, growing in rainforests, wet areas, and along riverbanks; the remaining seven species have inedible seeds due to their bitter taste.

2. Macadamia is a deciduous tree, classified in the nut category, with hard-shelled seeds, a kernel yield of 30-50%, and oil content in the kernel of 71-80%. Macadamia kernels are used as fillings for sweet pastries, chocolate, ice cream, boxed cakes, or consumed directly in canned form. 3. Macadamia was introduced and widely cultivated in Hawaii since the 1930s, followed by extensive cultivation in Australia from 1960 onwards. Currently, macadamia is also grown in other places such as China, South Africa, Kenya, Zimbabwe, Israel, California, Guatemala, Brazil, Costa Rica, etc.II. PLANTING CONDITIONS 1. Climatea) Average temperature: 15°C-35°C, most suitable 20°C-25°C; 3. Macadamia was introduced and widely cultivated in Hawaii since the 1930s, followed by extensive cultivation in Australia from 1960 onwards. Currently, macadamia is also grown in other places such as China, South Africa, Kenya, Zimbabwe, Israel, California, Guatemala, Brazil, Costa Rica, etc. b) Annual average rainfall: 1600mm-2500mm;c) Elevation above sea level: 10m-1200m; 3. Macadamia was introduced and widely cultivated in Hawaii since the 1930s, followed by extensive cultivation in Australia from 1960 onwards. Currently, macadamia is also grown in other places such as China, South Africa, Kenya, Zimbabwe, Israel, California, Guatemala, Brazil, Costa Rica, etc. d) Areas less affected by hot winds (Lao wind), salt fog, and drizzle.2. Soil and Topography

a) Soil: Should only be planted in good soil areas, preferably where the soil depth exceeds 50 cm, with a light to medium texture, good drainage, rich in organic matter, pH (KCl) = 4-6.5; not to be planted on sandy, waterlogged, or acid sulfate soils;

b) Topography: Relatively flat, slope less than 20°.

III. SEEDLING PROPAGATION TECHNIQUES USING GRAFTING METHODS

a) Selecting the nursery area:

The nursery area must meet the following conditions:

Convenient for transporting seedlings and close to irrigation water sources; well-ventilated, flat, and well-drained; soil with a light to medium texture.

b) Preparing the soil and forming beds:

- Clear weeds and roots thoroughly, plow and harrow the land finely before forming beds;

- For seed beds: Bed width 1m, length 8-10m; bed trench width 50-60cm from the edge of the bed; flatten the bed surface, create a bed ridge, then cover the bed surface with yellow sand (river or stream sand), thickness of the sand layer 15-20cm; sand is treated clean by watering it with a solution of Benlate C at a concentration of 0.3% or potassium permanganate (KMnO4) at a concentration of 0.1%; amount of water applied 10 liters per 10m

- For seedling beds: Bed size equal to 4-6 pots placed side by side; ensure a flat bed surface with good drainage.

c) Constructing shade structures: Shade structures are used to provide shade and prevent direct sunlight over the entire nursery area. Shade structures are made of black nylon mesh with a shading rate of 60-75% or by greenhouse nylon roof; height of the shade structure from 2.5-3m; dimensions of the shade structure's width and length equal to the nursery area dimensions;

d) Constructing humidity retention structures: Humidity retention structures are used to retain moisture, maintain temperature, and protect seeds and seedlings from direct rain and sun. Humidity retention structures are made of white nylon covering a semi-circular frame of bamboo or steel; width of the humidity retention structure 1-1.2m.

1. Preparation work

đ) Preparing materials, fertilizers, tools, and chemicals: Polyethylene pots with dimensions 20x30cm or 25x35cm, each with 4-6 holes at the bottom; specialized grafting tape; nursery soil for potting; composted manure, superphosphate (P2O5); NPK fertilizer (7:7:3 or 13:13:3); quicklime (CaO); fungicides such as Benlate C or potassium permanganate (KMnO4) and necessary tools (shovel, spade, pruning shears, grafting knife, bucket for collecting scions, pot, wet cloth, nylon bag, foam box).

2. Creating rootstocks

a) Germination:

- After harvesting, the fruits are peeled to extract the seeds, selecting plump, round, dark brown seeds of uniform size without pests or diseases, and sowing within 15 days; treating the seeds by soaking them in a fungicide solution of Benlate C at a concentration of 0.5% for 6-8 hours, then draining them; formula for preparing the Benlate C solution: 0.05 grams of Benlate C mixed with 1 liter of clean water;

- After treatment, sow the seeds on the bed surface in rows, spacing between rows 4-5cm, spacing between seeds in the row 2-3cm (equivalent to 7-10kg of seeds per square meter); when sowing, orient the seed stem upwards and the seed hilum downwards; after sowing, cover the seeds with a thin layer of sand 4-5cm thick; use a nylon humidity retention structure to cover the seed bed to retain moisture and protect from rain and direct sunlight;

- Water twice daily using a shower head watering can; apply 3-5 liters of water per square meter; maintain moisture from sowing until transplanting the seedlings about 30-35 days later; regularly guard against ants and other harmful insects; seeds will begin to germinate 20-30 days after sowing.₄b) Potting:²;

- Prepare potting mix consisting of 69% good soil with a light texture, mixed evenly with 30% composted manure and 1% superphosphate;

- Fill the pots by placing the potting mix into polyethylene bags in layers gently compressed; place the pots on the bed; arrange 4-6 pots side by side; leave one row empty every two rows;

- Prevent and control fungal diseases by watering the pot bed with a solution of Benlate C at a concentration of 0.3% or potassium permanganate (KMnO4) at a concentration of 0.1% before transplanting the seedlings 3-4 hours prior; apply 4-5 liters of water per square meter.

c) Transplanting seedlings into pots:₂O₅); NPK fertilizer (7:7:3 or 13:13:3); lime powder (CaO); fungicides: Benlate C or potassium permanganate (KMnO₄) and necessary tools (shovel, spade, pruning shears, grafting knife, bucket for scion branches, pot, wet cloth, nylon bag, foam box).

2. Rootstock production

a) Seedling cultivation:

- After harvesting, the fruit is peeled to extract seeds; select plump, round seeds with dark brown shells, uniform size, free from pests and diseases, and sow within 15 days at most; treat the seeds by soaking them in a fungicide solution of Benlate C at a concentration of 0.5% for 6-8 hours, then drain and dry; the formula for preparing the Benlate C solution is 0.05 grams of Benlate C mixed with 1 liter of clean water;

- After treatment, sow the seeds on the seedbed in rows, with a distance of 4-5 cm between rows and 2-3 cm between seeds within each row (equivalent to 7-10 kg of seeds per square meter);²when sowing, orient the seed so that the stem end faces upwards and the hilum faces downwards; cover the seeds with a thin layer of sand 4-5 cm thick; cover the seedbed with a nylon arch to maintain moisture and protect from direct rain and sunlight;

- Water twice daily using a watering can with a shower head; apply 3-5 liters of water per square meter; maintain watering until the seedlings are transplanted, approximately 30-35 days after sowing; regularly prevent and control ants and other harmful insects; seeds will begin to germinate 20-30 days after sowing.²b) Pot preparation:

- Prepare the potting mix consisting of 69% well-draining soil with light texture, thoroughly mixed with 30% composted manure and 1% superphosphate;

- Fill the pots by layering the potting mix into polyethylene bags under slight pressure; place the filled pots on the potting bed; arrange 4-6 pots side by side; leave one row empty every two rows;

- Prevent and control fungal diseases by spraying a solution of Benlate C at a concentration of 0.3% or potassium permanganate (KMnO

) at a concentration of 0.1% on the potting bed three to four hours before transplanting the seedlings; apply 4-5 liters of solution per square meter;₄c) Transplanting seedlings into pots:².

c) Planting seedlings into pots:

- Select seedlings: Choose seedlings with 2-4 leaves, normally developed, free from pests and diseases; use hands or tools to carefully uproot the seedlings without breaking the roots or separating the seeds from the seedlings;

- Transplant seedlings: Use a sharp pointed stick with a width of 2-3 cm (transplanting tool) to poke a hole in the center of the soil ball; the size of the hole should be larger than the diameter of the root cluster and the seed of the seedling, and the depth of the hole should be deeper than the length of the roots; place the roots and seed of the seedling into the hole, keep the seedling upright, and gently press the soil around the roots and seed with the transplanting tool;

d) Care for the rootstock:

- Water the plants with clean water twice a day in the early morning and late evening; the amount of water applied is 5-6 liters/m²; regularly weed and remove the surface crust of the soil ball; spray fungicides and insecticides to prevent anthracnose and leaf-eating insects;

- Apply top-dressing fertilizer using NPK (13:13:3) fertilizer that has been soaked, mashed, and mixed thoroughly with water to create a solution with a concentration of 1% (ratio of 10 grams of fertilizer per 1 liter of water); the amount of water applied is 5-6 liters/m²; after applying the fertilizer, rinse the leaves with clean water;

- The rootstocks are nurtured for 12-15 months before being classified into healthy, well-growing plants free from pests and diseases, which are then transferred to separate beds 1-2 months before grafting;

- The rootstocks must have a stem diameter of 0.8-1.3 cm and a height of 0.5-0.7 meters when selected for grafting;

3. Creating grafted plants

a) Selection of scion trees:

- Scion trees are either parent trees or orchards of parent trees planted with seedlings propagated asexually from Macadamia nut varieties recognized by the Ministry of Agriculture and Rural Development; current varieties include: OC, 246, 816, 842, Daddow, 695, 741, 800, 900, 849;

- The age of the scion trees must reach at least 3 years old; the harvesting period for scions, each parent tree can only provide scions for grafting within the first 15 years;

b) Selection of scions:

- Select secondary branches (second and third level) in the canopy where they receive full sunlight; do not take branches that are shaded, overgrown, or affected by pests and diseases;

- Standards for scions, choose those that have lignified but are not too old, aged 1-1.5 years; the diameter should be 0.7-1.0 cm, equivalent to or smaller than the diameter of the rootstock at a position 25-35 cm above the soil surface; the bark color should be dark brown or grayish green; the more buds on the branch, the better;

- The number of scions taken from each tree annually depends on the age of the tree, for trees aged 3-5 years, no more than 100 scions per tree; for trees aged 6-8 years, no more than 200 scions per tree; for trees aged 9-10 years, no more than 400 scions per tree;

c) Technique for cutting scions:

- Use sharp scissors to cut scions from parent trees, with a length of about 30-50 cm; cut all leaves on the scion or leave some leaves but trim two-thirds of their area;

- Scions cut from trees of the same variety should be kept separately and then grafted into individual beds; scions should be wrapped in wet cloth to maintain moisture, then transported back for cutting and grafting on the same day; scions without leaves can be stored until the next day;

- The timing for cutting scions is from September of the previous year to March of the following year;

d) Preparation of scion cuttings:

- Use scissors to cut scions into cuttings of about 8-12 cm in length, with a diameter corresponding to the rootstock; each cutting must have at least two sets of leaves; do not use cuttings from the tip of the branch for grafting; use a grafting knife to smooth both ends of the cuttings;

- Bundle the cuttings into small bunches according to each variety, wrap them in wet fabric or newspaper bags, then place them in foam boxes or plastic bags; take out the cuttings as needed for grafting;

đ) Preparation of rootstocks:

- Use scissors to cut the top part of the rootstock tree; the cutting point should be about 25-35 cm above the soil surface; cut 2-3 sets of leaves near the cutting point of the rootstock, leaving lower sets of leaves intact;

e) Grafting technique;

- The grafting season is from September of the previous year to March of the following year, with the best time being from November of the previous year to March of the following year; it is advisable to perform grafting on cloudy days, absolutely avoiding rainy days;

- Continuous grafting: At a point below the previously cut top, use a sharp knife to make a slanted cut on the rootstock trunk from bottom to top, about 3-4 cm long; the cutting action must be quick and decisive, creating a flat, smooth surface to minimize sap loss and ensure good contact between the scion and rootstock; the cutting end of the scion is also made slanted from top to bottom, about 3-4 cm long; align the slanted end of the scion with the slanted surface of the rootstock so that the surfaces fit tightly together; secure and protect the graft site with grafting tape;

- Inlay grafting: At the cutting point, use a knife to split the surface of the cut vertically along the trunk, about 2.5-3 cm long; the cutting end of the scion is made slanted on both sides at the base, about 2.5-3 cm long; insert the slanted end of the scion into the split of the rootstock so that the surfaces fit tightly together; secure and protect the graft site with grafting tape;

- Grafting tape wrapping technique:

+ For scion cuttings without leaves: Use specialized grafting tape to tightly wrap clockwise from bottom to top; overlap each layer, starting from the grafting point (the contact area between the rootstock and scion) up to the top of the scion, then reverse the direction of the tape to wrap counterclockwise down to the grafting point, wrap an additional 2-4 turns and tie the tape securely;

+ For scion cuttings with leaves: Use specialized grafting tape or homemade nylon tape to tightly wrap in the same manner, starting from the grafting point, wrap upwards about 1-2 cm (leaving 4-6 cm of un-wrapped scion), then reverse the direction to wrap back to the grafting point and tie securely; cover the scion above the grafting point with a small white nylon bag suitable for the size of the scion, tie the bag tightly to prevent rainwater or irrigation water from seeping into the grafting site (homemade nylon tape requires selecting white, soft nylon);

f) Arranging beds of grafted plants:

- Grafted plants with leaf-bearing and non-leaf-bearing scion cuttings should be arranged in separate beds and according to specific varieties to apply different care regimes and manage certification of the origin of the plant seedling lot in the future;

- Beds of grafted plants with leaf-bearing scion cuttings need to be covered with a nylon arch with a radius of 1-1.2 meters; the covering period lasts 45-55 days, and the nylon arch can be removed when the scion cuttings sprout to a length of 2-3 cm;

g) Care techniques for grafted plants:

- For cuttings without leaves: Water twice a day in the early morning and late afternoon using a watering can with a shower head, approximately 4-5 liters/m.², do not water at the grafting site;

- For cuttings with leaves: Water around the outside of the planting trench so that the water seeps into the trench base, from which it will permeate up to the grafted cutting ball;

- After each rain, if there is water in the nylon bag covering the grafted cutting, remove the bag and shake out all the water, then cover again; when the grafted cutting sprouts 2-4 leaves, remove the bag to allow normal growth of the sprout; each cutting should only retain 1-2 sprouts; regularly prune any shoots from the grafting base;

- Top-dressing and weeding: When the grafted sprout has 6-8 leaves, apply NPK fertilizer (13:13:3) diluted to a concentration of 1%, with an average application rate of about 2-3 liters/m²; apply every 10 days; water in the late afternoon, do not water immediately after new leaves emerge; weed regularly every month, break up the surface of the soil ball;

- Adjust shading: Once the grafted plant has stable sprouting (after 3-4 months of grafting), gradually reduce the shading structure's coverage to 30-40%; before transplanting the grafted plants, completely remove the shading structure 1-2 months prior to acclimatize the grafted plants to the planting conditions;

- Turn the pots: One month before planting, turn the pots and sort the grafted plants, separate those with good growth, free from pests and diseases, and height ≥ 50cm for preparation to be transplanted; those with poorer growth continue to be cared for until they meet the standards for planting (note that they must still be arranged in separate rows according to the principle);

i) Standards for grafted plants for planting:

- Grafted plants must have a post-graft period of over 6 months; the height of the grafted sprout, once lignified, should be 20 cm or more (overall height of the grafted plant over 50 cm); stem diameter at the root collar should be 1.0-1.5 cm;

- Plants should grow well, be free from pests and diseases, have green leaves, and normal leaf blade development.

IV. PLANTING TECHNIQUES

1. Planting method, density, and season

a) Macadamia trees can be planted in two methods: monoculture or intercropping with coffee, tea, or pepper:

- Monoculture with a density of 205 trees/ha (spacing 7 x 7m) to 278 trees/ha (spacing 6 x 6m);

- Intercropping on coffee planting beds with a density of 124 trees/ha (spacing 9 x 9m), 138 trees/ha (spacing 12 x 6m), pepper with a density of 124 trees/ha (spacing 9 x 9m), tea with a density of 111 trees (spacing 15x6m).

b) The best planting season is spring for northern provinces; for southern provinces, plant at the beginning of the rainy season.

2. Surface treatment, land preparation, digging and filling holes

a) Clear the area thoroughly to reduce weeds, pests, and avoid nutrient competition. Dig or loosen the soil locally around the hole position, 1.5-2m² wide, remove large roots (over 2cm) cleanly, for sloping areas (<20°) create terraces along contour lines with a width of 2-4m;

b) Dig holes measuring 80 x 80 x 60 cm, which should be dug at least 1-1.5 months before planting to expose them to the sun; when digging, separate the topsoil layer to mix with organic fertilizer when refilling the hole;

c) Apply organic fertilizer and fill the holes at least 1.5 months before planting; each hole receives 50 kg of compost or microbial fertilizer (according to package instructions), 500g NPK, and 300g lime powder mixed evenly with the topsoil; refill the hole with surrounding topsoil, forming a turtle-back shape 2-3cm higher than the natural ground level.

3. Planting techniques

a) On each planting unit, plant 4-5 rows of Macadamia (do not plant single rows); arrange the rows alternately to increase fruit set rates, enhance disease resistance, reduce crop failure risks, especially increasing the first-grade seed ratio according to international standards;

b) Use a spade to dig a hole about 40 cm deep in the center of the filled hole, wide enough to accommodate the root ball;

c) Cut open the nylon bag from the root ball; place the root ball straight in the center of the hole, ensuring the tree stands upright; fill the hole with soil and tamp down firmly; mound soil around the base of the tree 40 cm wide in a turtle-back shape, about 5cm higher than the ground level to facilitate drainage during rain; handle gently to avoid breaking the root ball;

d) Use three stakes, 60-80 cm long, driven into the ground around the tree in a triangular formation, 40-50 cm away from the base, tie the upper part of the stakes together corresponding to 2/3 of the tree height and secure them to the trunk to stabilize and protect the tree from wind damage;

e) Cover the ground around the base of the tree with straw, grass, or mulch to a depth of 4-5 cm, 1m wide, to retain moisture and prevent weeds.

V. CARE AND MAINTENANCE TECHNIQUES FOR PLANTED TREES

1. Care

a) If there is no rain after planting, water daily for at least 20 days to help the tree recover and produce new buds; in the following two months, water weekly; apply 10-15 liters/tree;

b) Loosen the soil and weed within a radius of 0.8-1m around the base of the tree; care for the trees twice a year and perform these tasks annually.

2. Top-dressing

a) Top-dress when the tree is two years old or older, applying in January-February each year with compost combined with NPK and lime;

b) Dig trenches 25-35cm wide and deep along the projection of the canopy, spread compost evenly, then sprinkle lime, add a thin layer of topsoil, mix thoroughly, and finally spread NPK and refill the soil, specifically:

- Year 2: Apply 10-20kg of compost or microbial fertilizer (according to package instructions) combined with 0.1kg NPK and 0.1kg lime;

- Year 3: Apply 20-30kg of compost or microbial fertilizer (according to package instructions) combined with 0.2kg NPK and 0.1kg lime;

- Year 4: Apply 30-40kg of compost or microbial fertilizer (according to package instructions) combined with 0.3kg NPK and 0.1kg lime;

- Year 5: Apply 40-50kg of compost or microbial fertilizer (according to package instructions) combined with 0.4kg NPK and 0.1kg lime;

- Subsequent years when the tree starts bearing fruit: Apply 50-70kg of compost or microbial fertilizer (according to package instructions) combined with 1.0kg phosphorus and 0.2-0.4kg potassium and 0.1kg lime.

- Application time: In the Central Highlands, apply in August-September; in Northwest, apply in October-November; apply after harvesting fruits and pruning branches to shape the canopy.

3. Pest control

a) Lime the base of the tree twice a year, the first time from December of the previous year to January of the next year; the second time in July-August to prevent pest infestations;

b) Start lime application from 2 cm below the base of the tree, extending upwards to about 50-80cm on the trunk;

c) Regularly inspect the trunk; if trunk-boring pests are found, inject insecticide into the boreholes with a syringe, then seal the holes with clay.

4. Pruning and shaping

a) Carry out pruning and shaping in the first and second years;

b) Depending on specific conditions, for trees with strong apical growth, cut the top of the main stem to promote branching; for trees with weak apical growth, there is no need to cut the top of the main stem, only trim the tops of lateral branches;

c) Top cutting is carried out three times: the first time at a height of 1 meter from the ground; the second time at a position 0.6-0.8 meters above the first cut; the third time 0.6-0.8 meters above the second cut;

d) Select healthy branches (2-3 branches) to retain, prune off weak branches;

e) After the second year, allow the tree to develop normally, in subsequent years only prune very small branches developing in the third canopy layer for trees with overly dense canopies.

VI. HARVESTING TECHNIQUES AND PRELIMINARY PROCESSING AND STORAGE OF SEEDS

1. Harvesting techniques

a) When ripe, the outer skin of the Mắc ca fruit will dry and crack along the direction from the protruding nipple to the fruit stem; the seed coat changes from light brown to dark brown, the seed coat becomes hard, then the fruit falls naturally;

b) The fruit ripening season in the Central Highlands is from late July to September; in the North, it ripens from mid-August to mid-October;

c) One to two weeks before the fruit falls, clean the forest (orchard) rows, remove weeds, dried husks, leaves...to facilitate harvesting;

d) Pick up ripe fruits that have fallen to the ground by hand, or spread nylon nets or plastic sheets under the trees to collect the fallen fruits and gather them together.

2. Preliminary processing and storage of seeds

a) Ripe fruits that fall to the ground must be harvested immediately, within 24 hours after harvesting, peel the fresh fruit skin and dry the seeds, for remaining unpeeled fruits, spread them thinly on the floor, turn on fans to cool and ventilate; do not expose the fruits to direct sunlight;

b) In case of manual peeling, use a wooden hammer with a thin rubber pad on the hammer head, hit the fruit until the skin breaks, then extract the seed; avoid damaging the seed, affecting its quality; the fruit skin after peeling can be composted as organic fertilizer;

c) Remove broken pieces, diseased fruits and seeds, germinated seeds, cracked seeds, small seeds, seeds with low kernel ratio; then dry the seeds as follows:

- Natural drying: Spread the peeled seeds in a thick layer of 10-15 cm on a well-ventilated indoor or covered outdoor surface; turn the layer three times a week, after 1.5-2 months, the moisture content will decrease to 10-15%;

- Artificial drying (for large-scale production): Dry the seeds at 30°C for 5 days, then increase to 38°C for 1-2 days, further increase to 45°C for 1 day, and finally increase to 50°C for 1-2 days, the moisture content of the seeds will be reduced to 1.5-5%;

d) Seed storage:

- Seeds should be processed immediately after drying;

- If not processed, seeds should be stored in sealed plastic or metal containers, or vacuum-sealed bags; store the containers, bags, or packages in a cool, airy place. Naturally dried seeds can be stored and kept for no more than six months; artificially dried seeds can be stored for a longer period.