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Varieties in New Zealand
& MAGS THE NATURAL FOOD HUB
Inc. 'Nut Grower Fact Sheet' Macadamias
in the Bay of Plenty
The article below is reproduced by permission
of the New Zealand Macadamia Society.
Society Inc. 'Nut Grower Fact Sheet'
Nut Grower Fact Sheet 2000
The New Zealand Macadamia Society Inc.
725 Harrisville Rd
R D 2, Pukekohe
The Macadamia nut is a native of Australia and is a member of the
family and related to the NZ Rewarewa. Two species are grown
for food production, the macadamia tetraphylla and the macadamia
New Zealand provides a special opportunity to grow a clean healthy
product. Today, total world macadamia production accounts for less than
0.5% of the world trade in nuts. New Zealand produces less then 1% of
Macadamias require temperate climates and areas that have low frost
risk though, as mature trees they will withstand minus 6 degrees - in
if tamarillos can be grown so can Macadamias. Orchards are found in
areas of Northland, Auckland, Taranaki, Coromandel, Bay of Plenty, East
Cape and Hawkes Bay. Macadamias flourish best in soil rich in organic
but can tolerate a wide range of soils from heavy clay to sandy loam.
requirements include free draining, a good pH balance 5 - 6.5.
and shelter from severe winds is generally needed for young trees.
All macadamia trees grown for commercial purposes are grafted; there
are approximately 600 different varieties not all of which are
in NZ. Macadamia integrifolia grows in the warmer climate of
NSW and Queensland. Its production is sporadic in NZ, as it needs high
temperatures and high light intensity. Macadamia tetraphylla
from NSW and is more tolerant of the cooler climate. When choosing
varieties to plant you should consider the following:
It is advised to always plant a mixture of varieties scattered evenly
the orchard in order to ensure adequate pollination. The specific site
will determine exact ratios and varieties. You may also choose to talk
to your local nut processor. Some varieties crop better under certain
and do well with the correct pollinators along side. Today in NZ most
are good croppers in their own right. The society can put you in touch
with consultants and nurseries to help you with selection of suitable
How warm is my site?
Do I want to hand pick or harvest from the ground?
Is the terrain suited to mechanical harvesting?
How many trees will I be planting?
Macadamias are best planted in the spring but can be planted at other
times with extra care from drought, frost, etc. Trees are best planted,
in rows, with a spacing of 7m apart and 5m minimum between trees, which
allows for plenty of access, light penetration and access for insects
assist pollination. This allows for about 110 trees per acre or 280 per
hectare. Allow headroom at the end of rows for machinery access and
A northerly aspect is preferred and the use of shelterbelts needs to be
planned to protect young trees from prevailing winds, this is
removed as the trees come into production. Consider the availability of
irrigation and drainage. Carefully consider the mixture of varieties
will plant and intersperse them well. Planting varieties which all
the same variety characteristics eases the handling of the post harvest
The macadamia is a forgiving tree and is suitable for those with
spare time, but they respond well when cared for. The health benefits
habitually eating macadamias augurs well for their continued demand.
Seasonal pruning for shape and light is typically done in winter.
the tree can be of substantial size, modern management maintains trees
to a manageable height.
WEED AND PEST CONTROL
The Green Vegetable Bug Nezara viridula is the most serious threat,
piercing the nut, staining the kernel and rendering it valueless.
mowing is recommended to keep the grass and weeds under control. Sheep
are used in some mature orchards. Livestock is not recommended in the
four or five years and never goats. Rats can be a problem so effective
eradication programs are essential. Possums may also eat soft green
The Society is working to establish the best methods of controlling
pests, and the results of research will be published to members, as
Annual leaf and soil analysis, with appropriate response, assists in
maintaining healthy trees.
Nuts are generally ready to harvest late May or early June, but can
be later depending on the latitude picking can go on until late
Nuts are picked by hand or mechanically depending on the variety of
Top orchards in New Zealand have returned yields similar to the best
overseas, i.e. 4-6 tonnes per hectare. In optimum conditions an 8 yr
tree can produce 8kgs nut in shell, increasing annually for a further
years, with the approximate price of $3 / kg in 1999. Many orchards not
achieving above two tonnes per hectare are found to have basic
These problems include cool sites, shady places, poor
poor nutrition and crowded planting.
HUSKING AND DRYING
The object of husking and drying is to produce nuts that are crisp,
light in colour and free from blemishes. Nuts should be husked as soon
as possible after picking, within 24 hours is best. The Society may be
able to help you find someone to work in with nearby. Moisture must be
reduced to 1.5% for processing this can be assisted by hanging in onion
sacks for 8 - 12 weeks depending on the ambient temperature and
The dryer the nut the better the storage characteristics and eventually
the better the payout received. The nut should be firm and crisp. A
that is soft and doughy when bitten indicates that further drying is
Most orchards sell their crop as nut in shell (NIS) to processing
Contact the society for a list of these.
Packaging to reduce exposure to light, moisture and oxygen enhances
the final taste of the nuts, and increases the shelf life. The society
has developed criteria to ensure the highest standards are maintained.
The New Zealand Macadamia Society Incorporated is developing a number
of exciting new marketing initiatives designed to increase the
and demand of New Zealand macadamia nuts. Interestingly, in 1999, New
was still importing a large percentage of its macadamias from
For more detail information send $5 and S.A.E.
N Z Macadamia Society Inc.,
997 Beach Rd,
Information on current initiatives can be obtained by contacting the
This document is
to be copied and distributed. The intent of this document is to
a brief overview of the issues involved in planting a macadamia
It is not intended as an authoritative publication and no
is taken for the reliability of any of the information contained in it.
It is recommended expert advice be sought, or more detailed information
obtained from the growers guide (Send $5 and SAE to The NZ Macadamia
Inc.) before any investment is made.
Note: although they don't include the copyright notice. this
work is '© Copyright The
NZ Macadamia Society Inc', regardless that it is permitted to freely
Reproduced with permission
of the NZTCA
in the Bay of Plenty
Nick Nelson-Parker reports on a BOP Branch visit to Beverly Davy
& Robin Moyle's macadamia orchard.
Macadamias are considered by most to be a golden crop- you pay gold to
buy them to eat. However, the reality in New Zealand is that most
are cropping so poorly that the owner is making copper rather than
Therefore, when our branch had a field day to a macadamia orchard that
was realizing its potential, I felt the information shared required a
In September 1988, Beverly and Robin purchased this 2.5 ha property
at Whanarau Bay, on the western tip of East Cape. About three gates
the road is a newly-planted banana orchard, and every flat paddock for
the previous haalf hours driving is clothed in the most luxurious
plants. It is obviously a warm spot, and the soil looks fertile. Inside
the orchard, it is clear that the owners are in full control. The
the hedges and the macadamia trees are immaculate.
In 1989 their frist crop was 1.5 tonnes off 370 trees aged five to
Even though this is quite good for New Zealand, Beverley turned her
to improving this yeild. By winter 1993, after a fairly poor
they had increased the crop to 4.2 tonnes off the 370 trees. That is 12
kg per tree. Many other commercial orchards in this country are only
2 kg or less per tree. Some are getting 8 kg per tree in some years.
yeild from mature macadamiaas in Hawaii is over 16 kgs per tree, and
be as high as 68 kgs from a 10 year old tree. Beverly expects to pick 6
tonnes in 1994. How did they get this lift, and how do they plan to
yeilds even higher?
They embarked on a programme of recording the crop off each tree, and
what the neighbouring varieties were. Beverly found that the main
Beaumont, was giving good yeilds, but that pollination was
In addition, one tree of PA39 gave extremely good crops. She observed
biennial bearing was occuring. And she noticed that sometimes, although
there were plenty of flowers, only a few nuts would set on each stalk.
This occured even when the crop was next to the best pollinator. She
noticed deficiency symptoms showing up in the leaves as the crop
to fill out in the trees, even though they put a commercial fertilizer
dressing on the orchard each year.
They decided to monitor the nutrient levels by having regular foliar
analyses done. Beverley had read that research in Australia linked high
boron levels with a good nut set, so they included a check on their
levels. These tests confirmed what Beverly's eyes were telling her:
nutrient levels were not adequate all the time, and that boron levels
be higher. Beverly and Robin decided to increase the basic fertilizer
and correct these deficiencies. They also increased nitrogen levels,
the prevailing Australian and New Zealand belief that high levels of
prevent macadamias from cropping. In 1993 they applied four sprays of
and boron starting in January, applied 900 kgs of Nitrophoska blue in
and then did another foliar analysis in November to assess the
Because the nut set had been so good, probably as a result of the boron
spray, the trees were already short of nutrient! A 250 kg dressing of
Ammonium Nitrate together with 300 kg of Causmag was applied to see the
trees through developing the nuts. Iron was also added to the foliar
to correct spring deficiencies of that element. Sulphur deficiency is
a concern, and that is the next nutrient that Beverley wants to
Another aspect contributing to their success is orchard hygiene. When
initially purchased the orchard, their first crop had to be dumped
of bug damage. Well-mown grass, with strips sprayed between the trees,
helps to reduce green shield bug. In addition, they spray with AttackTM
four times at 7 day intervals, starting in February. They have reduced
the damage on their crop from 30% to 1% by this programme. It is
not to overspray the orchard and kill the leaf roller moth, because
is considered an important pollinator for macadamias.
Oppossums have not been a problem, but rats are a worry. When there
are macadamias to eat, they will not touch any other baits. In the
Beverly and Robin go around the orchard with long poles to remove all
old birds nests. Otherwise the rats would fill these with nuts and
need to come to the ground.
Another aspect of orchard hygiene is tree pruning. All the skirts on
trees are trimmed off to facilitate weed spraying and mowing.
the trees are being thinned out to allow better access for bees for
and also people for picking. The less dense trees appear to be cropping
better too. Attention to detail here is making the difference between
average orchard and one that is a top performer. Beverly is very
about how to prune her trees. This is especially important wth the
New Zealand varieties that have to have their nuts picked. The trees
be a central leader with branches spiralling around the centre at 70 cm
spacings. This makes the tree much less prone to breakage. Shelter is
for macadamias because the cooling effect of the wind retards their
Strong winds also cause their branches to break. If Beverly and Robin
planting a new orchard, they would first plant shelter, but not as much
as the original orchard. They would not plant eucalypts because they
greedy trees and they get too big.
Beverly and Robin's orchard presents an unique opportunity to compare
They have 23 different varieities already bearing, adjacent to each
and to different pollinators. In addition they have recently planted a
number of new varieties as a trial. This is a summary of
current information on varieties, but their nutrition programme could
these yeilds markedly.
This is an Australian variety. It has good taste, a high oil content,
and a crackout of 39%. However, the nut does not drop when ripe, giving
high picking costs. Drying is also a problem, as the kernel sticks to
shell on one side if it is not turned regularly in the early stages of
drying. The customer sees this as a basal stain on the kernel. A large
percentage of the kernel tends to fall in half. In 1993 a block of 8
old Beaumonts, with no pollinators except around the outside, gave 18
But 10 year old Beaumonts next to Nelmac 1 gave 22 kgs, while 10 year
Beaumonts next to Nelmac II averaged 28 kg per tree.
One 7 year old tree of this variety gave 33 kgs. Unfortunately they
have only a handful of PA39, and can only assume that other trees of
same variety would do as well. The kernel is clean and attractive. In
orchard they gave 95% grade 1 kernel, with a crack out of 40%. Another
great virtue is that the nuts drop when ripe. It pollinates Beaumont,
no figures are available to compare it as a pollinator to Nelmac II. It
is a small compact tree, very prickly, and very susceptible to green
PA39 is one of Brian Piper's selections. However, none of the other
Brian Piper selections have performed well in this orchard.
A South African cultivar. Although the nut is slightly elliptical.
which makes cracking awkward, and has a low crack out because of the
shell, processors like this variety because of the high quality kernel.
It has a bland taste like the Hawaiian nuts, and a high oil content.
It is quite a light cropper, with a10 year old trees yielding an
of 8 kg, It is a month late in flowering, which may be hindering its
effect on Beaumont and its own cropping. However, if the pollination
be corrected, it would be a very good variety because the nuts drop
Another South African cultivar. It has a sweet nut, which means that
it has to be cooked carefully so that the sugars do not caramelise. The
sweet nut does not taste good when processed, but people who eat it
relish the taste. The nut is too big for processors, and has an open
(hole in the shell) which lets in mould. The crack out percentage is
Ten year old trees average 22 kgs per tree.
It is a popular variety because of its pollination of Beaumont, and
the yields are almost comparable. It appears to be susceptible to iron
chlorosis, with bleached leaves showing up in early summer when the
is under stress.
A Gordon Titirangi selection. It was released as a pollinator for
Beaumont, but it is probably better pollinated by Beaumont. The
nut is small and of good quality, with a high oil content. The kernel
clean and attractive, and the crack out is high.
Another Gordon Titirangi selection. This nut has a thin shell, so rat
depredation and shield bug damage are both real problems. Nine year old
trees gave 8 kg per tree.
Another Gordon Titirangi selection, selected as a pollinator for
It has a good quality nut.
Another Gordon Titirangi selection. Beverly has only just planted this
variety. It had 100% grade 1 nuts at Woodhill. [Auckland]
A Hawaiian variety. This produces the best quality nut they have to
work with in their little processing set-up. The crack out is 32%. Nine
year old trees produced 22 kgs each, though the nuts do not drop when
are ripe. It is a good pollinator for Beaumont, and appears to be
self fertile on their orchard.
Is a pure M. tetraphylla from Australia. It is a good
for Beaumont. Seven year old trees produced 7-5 kgs.
An Australian hybrid selection. The nut is large and of good quality.
It is popular in Australia as a rootstock.
Is another of those varieties not planted much, but often used in
new varieties. Its good characteristics include the yield (17 kgs off 9
year old trees), the fact that it drops when ripe, and a kernel of
good quality. On the other hand, the nut is elliptical, so is difficult
to handle for processing. The crack out is only 33%.
If they were doing it all again
Beverly is uncertain what varieties she would want to put her money on
a second time around. Ideally she would like to do away with all the
and just have varieties that drop when ripe. In spite of that problem,
there is presently no other proven variety with comparable yields.
the orchard would have a quarter Beaumont, planted in double rows. To
good pollination, every tree in the orchard would be next to a
variety on at least one side.
The pollinators would also be in double rows. These would possibly
be GT1, with as many PA39 as they could obtain. A certain number of
would also be included on a trial basis. Other considerations would be
Nelmac II, because of its good pollination of Beaumont, or Nelmac I, if
the cure for its poor pollination could be found.
Their spacing would be 6 x 6 metres as currently favoured in Australia.
There, they are finding that when they thin out the trees, the crop
drops for one year before the remaining trees make up the difference.
current Davy/Moyle orchard is planted at 4 x 5 metres.
Nagao, M A & Hirae, H H. 1992. 'Macadamia: Cultivation and
Critical Reviews in PLant Sciences 10 (5): 441-470
Richardson, A C & Dawson, T E. 1993. 'The Nutrition
of Macadamia Trees in New Zealand'
of the New
Zealand Tree Crops Association from 'The Tree Cropper', the
Journal of the New Zealand Tree Crops Association, Issue number 6,
(This article prints out at about 8 printer pages)
Note: this work is '©
Copyright Nick Nelson-Parker and The NZ Tree Crops
Inc', regardless that it is permitted to freely distribute it.
The Orchardist of New Zealand 66 (9): 37-40 (October 1993)
MacNuts in Helensville, North Auckland, publish this good growers
Covers: Location, Varieties, Planting, Pruning, Weed &
Pest Control, Fertiliser,Yields, When to Harvest, Husking, Drying &
Macadamia Varieties in the New Zealand home garden - a Naturalhub
on home garden cultivars.
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