Best Macadamia nuts – Produce perfect kernels

                        Best macadamia nuts

Considered as the cream of the nuts by some, the smooth shell ( M. integrifolia) macadamia nut and it’s hybrids, indigenous to the Australian coastal rain forest regions of Southern Queensland and northern New South Wales, rank among the finest confectionery nuts in the world for texture and flavor. It commands a fairly high price and the consumer demand is ever-increasing. High quality Macadamia oil is a sought after commodity.

                                   The Queen of nuts

To produce the best macadamia nuts for the export of perfect kernels and oil extraction, which is every nut producers dream, it takes a lot of planning and hard work. To help you achieve this dream have a look at these suggestions and recommendations.

Best macadamia nuts start in the nursery

The nursery is the beginning of the awesome nut. There are many things to be considered here. Experience has shown that only grafted tree’s of the best varieties will produce 3 – 5 times greater yield of kernels than ungrafted seedlings of the same age.

  • Site selection
  • Hygene
  • Layout
  • Bed construction and layout
  • Planting medium
  • Varieties for root stock and grafting
  • Fertilisation ,chemicals and biological controls of pest and diseases
  • Seedling selection
  • Grafting methods
  • Green houses and irrigation systems
  • Potting and potting mediums
  • Record keeping and plant identification
  • Logistics and input suppliers

                              Macadamia nursery

Establishing an orchard for export quality nuts

A orchard that produces high quality nuts consistently is one that has been well-established with a lot of planning, careful consideration and good management. It represents a long time investment with good soils favourable moisture conditions and a suitable climate macadamia nut tree’s are capable of producing satisfactory yields for 40 to 60 years.

Beautiful bunch of nuts

Good site selection is extremely important in growing macadamia tree’s. From available records it appears that well grown healthy tree’s continue to increase in productivity as they grow older and bigger. Older and bigger tree’s, when correctly spaced, present no difficulty because the nuts are harvested after they fall to the ground. It is no more difficult to collect the nuts under 15m high tree’s as it is to collect nuts under younger smaller tree’s.

Macadamia tree’s perform best in deep well draining soils rich in organic matter. Avoid steep sloping lands because of erosion and poor accessibility to tractors and equipment during spraying and harvesting operations.

Starting with site selection careful consideration must be given to the soils( type, PH, Drainage, slope), the elevation of the site, the general wind direction, annual rainfall, position of the site in relation to the processing plant and accessibility for tractors and equipment.

The planned orchard layout must consider and include wind breaks, irrigation pipe lines, overnight water storage dams, power lines, transformers for pump stations, land contours, drains, access roads, bridges, culverts, bee hive positioning, owl and bird of prey perches, in field sanitation for pickers, variety placement for cross pollination, bracing of young tree’s, tree line direction for sunlight optimization and planting distances and configurations.

      Macadamia in flower

Once this planning has been done the next phase is the logistical planning of land preparation, site preparation and finally the actual transplanting plan. At this time it is wise to consider the management and record keeping side of the orchard and complete your operational schedule. It is also a fine time to consider the processing plant positioning bearing in mind things like power supply and quantity of power available, communication systems, availability of water and sanitation without forgetting the maintenance side of the operation like workshops etc.

Management of macadamia orchards

To produce the best macadamia nuts and export quality kernels, the management of the orchard must be of a high standard as this is the most important part of the long term investment that has been made. The appropriate management strategies and actions are required to achieve the yield potential of the orchards. These may differ in intensity from orchard to orchard but are just as important as each other.

The criteria of integrated orchard management are :

  1. Canopy
  2. Orchard floor
  3. Drainage
  4. Fertilisation
  5. Irrigation and applications
  6. Pest and disease control

Pruning and training in the first two years after transplanting is very important. The frame work of a


well-balanced strong tree can only be achieved while the tree is young. Corrective pruning and bracing

Macadamia nut tree

in later years will not over come the effects of weak V shaped crotches and badly spaced, crowded main branches. This has a detrimental effect on yield and quality. Challenges in management strategies and actions grow with the tree’s.

Good canopy management achieves

  • Access for machinery and spraying equipment. Common spraying equipment can only reach about 8m.
  • Better light penetration into the producing top canopy and through onto the orchard floor for ground cover. Most macadamia pests prefer dark shady areas. Much needed ground cover requires adequit light to sustain it’s self. Erosion at the base of large tree’s from stem flow expose the fine feeder roots.
  • A highly productive canopy at manageable heights.

The two fold purpose of the orchard floor are that it is the work surface of the orchard and that it supports the important biological zone of the productive tree’s. Orchard floor management is the art of successfully maintaining :

  • Protection for the soil with ground cover be it live or mulch.
  • Creating ideal conditions for the tree’s feeder roots
  • Ensuring a good surface from which the nuts can be harvested.
  • Maintaining accessibility for tractors and equipment even after rains.

The drainage design will depend on the block size, position in the landscape and the rainfall. It is best to do the designing during the planning stages, before planting as it is easier to complete the earth works at this stage. The plan is to direct water run off in channels through the orchard at controlled flow rates to avoid erosion and loss of important soil nutrients.

Stem flow from large tree’s must be considered as it will alter the drainage flow patterns in the future.

Successful drainage management :

  • Directs and controls water run off through the farm
  • Minimises erosion and root exposure
  • Enables safe accessibility of tractors and equipment
  • Avoids water logging areas.

An orchard worth planting is an orchard worth taking good care of through good fertilizing practices.

The timing of leave sampling is critical to get optimal results. The leaves should be healthy, correctly selected, from alternate sides of the tree and be a fair representative of the orchard as a whole.The ideal practice is to send a soil sample from the same location together with the leaf sample. This sampling should be done annually. It is essential to use the results of both samples in determining the fertilizer requirements. The sampled tree’s should be marked and numbered for future identification. Organic fertilizers should always be considered as a viable option.

Fertilizer management :

  • Timely sampling leaf and soil
  • Correct annalisys
  • Proper and timely application of fertilizers and trace elements

Although irrigation is only recommended in areas where rainfall is less than 1200mm per annum or where rainfall is not evenly distributed through the year supplementary irrigation can significantly improve nut yield, size and quality.

Young tree’s assisted with supplementary irrigation during dry periods will assist in bring them into

                     Young macadamia tree

production sooner. Established orchards assisted by irrigation during critical periods will benefit yields, size and quality of the nuts. Research shows that water stress during flowering and early nut set can reduce yields. As nuts set and develop they become very sensitive to water stress. Yield and quality are most sensitive to water stress during the latter stages of nut maturity and when oil is accumulating in the kernels.

Irrigation essentials includes a good well-designed irrigation system that fits your situation and a monitoring system which allows you to schedule your water application to the required amount, depth and time.

Irrigation management :

  • Correct scheduling
  • Critical periods
  • Application quantity, timing

There are several pests and diseases that can have a detrimental effect on macadamia nut yields, size and quality.

The traditional approach of routine chemical spraying has been replaced by a more eco-friendly system called IPM ( Integrated pest management )

Integrated pest management involves a new approach to pest and disease control using less harsh chemical sprays and more monitoring scouting and recording and the introduction of beneficial insects.

The key elements of IPM

  • Growing hybrid varieties less susceptible to the disease
  • Introducing biological control measures like beneficial parasites or predatory insects
  • Placing monitoring systems to determine pest levels and pressure levels then only using soft chemicals when counts exceed set thresholds
  • Using chemicals that have the least impact on beneficials and the environment.


Basic processing the best macadamia nuts

                                        Laser sorter

Having put a huge amount of effort into producing the best macadamia nuts the aim is to contain that quality during the harvesting operations. Harvesting starts after the nuts have fallen to the ground completing a harvest round every two to four weeks. Harvesting frequently ensures the highest nut quality is maintained. The most common harvesting machine uses segmented wheels with fingers on the end that roll over the ground capturing the nuts between the fingers and picking them up. The harvested nuts are collected in a bin on the harvester.

The next stage of the process is dehusking the nuts. Dehusking is the process in which you remove the fibrous hard husk from the inner nut shell. The husks can be used as compost and to make up mulch for the tree’s. Dehusking nuts within twenty-four hours of collection is vital to ensure you get the most out of your nuts. The husk is high in sugar and if left molds soon start to develop. Ensure that the macadamia nuts remain in their designated batches and do not get mixed up with other batches.

There are various methods of dehusking the macadamia nuts:

  • tire dehusker ( More for small scale farmers)
  • Vertical channeled dehusker
  • Horizontal dehusker

From dehusking the next step is recording the moisture content, batch weight, the land or block it came from with the variety. Then it’s off to the dryers. The moisture content has to be dropped to 1.5% so the kernel pulls away from the nut shell. Once dried sufficiently the nut proceeds to the cracking machine where the nut shell is cracked and separated from the kernel. The nut proceeds through color sorters and laser sorters and a final hand sort and grading operation. There are various different grades and only the whole kernel of the top best grades are packed for export. The middle grades are generally used for the local markets with the other grades used for oil expression.

A brief over view of macadamia nut cultivation

Although this is a very basic over view of the rewarding cultivation of the best macadamia nut more in depth information is available on request from

Basically touching on the main points of the nursery, getting the orchard established, managing your awesome orchard and the basic processing procedures. It is a hope that the information will be beneficial and captivating enough to see more macadamia orchards springing up. There is nothing sweeter than the smell of a macadamia orchard in full blossom.

               The four stages of the best nuts






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