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MACADAMIA NUT (Macadamia integrifolia)

  • ICAR-Central Agroforestry Research Institute, Jhansi Uttar Pradesh


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Macadamia integrifolia)
boombera,burrawang (Hardner etal.,
2005) and considered as world finest
nut.TheMacadamianut,M. integrifolia
food plant of Australia, which has
Maximum commercial development has
years(Sharma et al.,2015).Itismainly
grown in tropical climates ofAustralia,
Brazil, Indonesia, Kenya, New Zealand
is the largest producer of Macadamia
nuts;whereas, nutinthe Hawaiiarethe
mostdelicious in taste and their delicate
flavourand crunchytexture makesthem
a delight to consume. It is a dark green
of macadamia nut has been presented in the Table 1.
Macadamia nuts are world’s most delicious nut with small in size, crispy buttery
flavoured nuts. Apart from being delicious, these nuts are good sources ofprotein and
minerals with sweet in taste and can beeaten either raw from the shell, dryroasted or
1. Introduction............................................... 583
2. History,OriginandDistribution.................584
3. AreaandProduction ................................. 585
4. Taxonomy ...................................................585
5. Species......................................................586
6. Cultivars .................................................... 588
7. Propagation ............................................... 591
8. Cultivation .................................................592
9. QualityCharacteristicsand
MaturityIndices........................................ 601
10. Harvesting ..................................................601
11. Yield .......................................................... 601
12. PostHarvestManagement ........................ 602
13. ValueAddition ...........................................603
14. TradeandMarketing .................................603
15. EffectofClimate Changeon
MacadamiaNut .........................................604
16. FutureResearchPlan................................ 605
17. OrganicCultivation....................................605
cakes, confectionery, ice cream, salads, roasts and casseroles to enhance the savour.
acidis abeneficiaryfattyacid,found higherinhumanliver.Theseacidincreasesinsulin
pancreatic beta cells.
Table1: NutritivevalueoftheMacadamianut
Nutrient Value Nutrient Value Nutrient Value
Energy 718Kcal Pyridoxine 0.275 mg Man ganese 4.131 mg
Carbohyd rates 13.82g Rib oflavin 0.162mg Phosphorus 18 8mg
Pro tein 7.91g Th iam in 1.195 mg Se len ium 3.6mcg
TotalFat 75.77g VitaminA 0IU Zinc 1 .30mg
Ch olesterol 0mg VitaminC 1.2mg Sodium 5mg
DietaryFiber 8.6g Vitam inE 0.24 mg Po tassium 368mg
Fo late s 11mcg Calc ium 85 mg Ph ytost erols 116mc g
Niacin 2.473 mg Copper 0.756 mg ßsitosterol 108mcg
Pantothenicacid 0 .758mg Iron 3.69mg
The macadamia nuthas originatedinAustra lia, morepr ecisely in the rain forests of the
southeastern Queensland and northeastern New SouthWales whereas he present day
macadamia nut iscreditedtohave developedin Hawaii,andfromtherethecropfurther
movedtoEastAfrica.Isolatedtreeof thisnutarefoundinnumberofsoutheastAsian
Mueller discoveredthemacadamianutanddecided toname thegenus after a colleague.
His name was John Macadam. Von Mueller was a noted chemist and physician who
encouraged macadamia nut cultivation. The macadamia genus consists of eight species,
twoofwhichproducenutswhichareaviablefoodsource.Thisgenus offloweringtrees
nuts.TheyaremainlyfoundinAustraliawitha species ortwo growinginIndonesiaand
New Caledonia. Macadamia nuts trees were imported to Hawaii for cultivation in the
1880sfor growingasawindbreakandlaterin1930;itscommercialpotentialfor dessert
nut was developed by university of Hawaii. Nowadays, most macadamia plantations
including eastern and southern Africa, and Central and LatinAmerica. Northern New
South Wales and southeastern Queensland are the region having high production of
worldwidefollowed byAustralia, around22percent, rest isproducedbyother countries
including Malawi,SouthAfrica, Kenya, Guatemala, Mexico, Brazil, Costa Rica, New
Zealand, CaliforniaandChina.
It belongs to the family Proteaceae of which about 1000 species exist including the
Banksias, Grevilleas, Stenocarpus, Dryandra, Hakea and Telope (Mc Conachie,
1980~ BenJeecov and Silber, 2006). Proteaceae, isan ancient angiosperm family whose
initial differentiation from ancestral forms occurredin the southeast ofAustralia 90100
millionyearsago.Thefamilyiswellknownforother generasuchasBanksia, Grevillea,
andHakea. Proteaceaeappeartohave been a majorcomponentof theearlyangiosperm
dominated rainforests whichonce covered most of Australia. Macadamia were probably
Kingdom: Plantae
Order: Proteales
Family: Proteaceae
Genus: Macadamia
Species: (i) integrifolia,
(ii) ternifolia,
4.1. Cytogenetic
Allthreespecieshavetheidentical somaticchromosomenumberof 2n=28.Thisreport
was the first on the chromosome numbers of M. ternifolia and M. tetraphylla. These
numbers were determined from root tips of M. ternifolia and M. tetraphylla seedlings,
and from dividing microsporocytes in M. tetraphylla. The chromosome number of M.
integrifolia was first reported by Darlington and Wylie (1955) as 2n = 28 (56), as a
previously unpublished number determined by Ukio Urata of the University of Hawaii.
The 56 in parentheses refers to a clone, Y279, which was discovered to be tetraploid.
Later, Urata (1954) published the numbers as n = 14 and n = 28.
AccordingtoCostelloetal. (2008)thegenusconsistsofninespecies.Thespeciesnative
to Australia are Macadamia integrifolia, M. tetraphylla, M. ternifolia, M. jansenii,
M. whelani, M. claudiensis and M. grandis, whereas M neurophylla is native to New
Caledonia and M. hildebrandii is native to Sulawesi in Indonesia. However, only the
witha bitter flavoured kernel(Mc Conachie,1980). The two edible Macadamia species
(phyllotaxy),leaftype, leafmarginalserrations andcolour of newgrowth(Ryan, 2006).
The Genus Macadamia (familyProteaceae), as presently understood, comprises ten
species of tropical and subtropical evergreen trees (Table 2).
S.No. Species Origin
1 M.hildebran dii Steenis Celeb es
2 M.Rousselii(Veill.)Sleumer NewCaledo nia
3 M.ve illardii(Brongn.andGris.)Sleumer
4 M.francii(Guill.)Sleumer
5 M.whelaniF.M.Bail. EasternAustr alia
6 M.ternifoliaF.Muell.
7 M.integrifoliaMaidenandBetche
8 M.tetraphyllaLAS.Johnson
9 M.prealta(F.Muell.)F.M.Bail
10 M.heyana(F.M.Bail.)Sleumer
5.1. Macadamiaintegrifolia (Queensland/Australiannut;bushnut;nutoak;
Bauplenut;smooth shellnut)
Plant: Trees are vigorous with dark green foliage, strong crotches and ascending ra ther
introducedcultivars, havemoreuprightgrowthhabitsthanKeauhouand‘Ikaika’,which
the row and thus more trees per acre. Individuals are often multi stemmed with small
crowns. Leaves: The simple obovate to narrowly oblong leaves are arranged in whorls
ofthreeoropposite,and5.5cmto14cmlongby 2.5cmto6cmwide(Stanley andRoss,
5 to 10mm long. Flowers: Axillary creamy white flowers are arranged in brush like
hanging racemes 10 to 30cm long. Flowering period isAugust to October with kernel
maturation from December to March, with mature nuts falling to the ground thereafter.
Fruits: Rounded fruits are green, 2.5 to 3.5cm wide with a hard brown inner shell
protecting the edible nut.
5.2.Macadamiajansenii (Bulburinnuttree)
Plant:The plantaresmall,singleormultistemmedtree69m tall,with generallysmooth
bark dotted with prominent lenticels (Halford, 1997).
Leaves: The leaves are oblanceolate to oblongelliptic and are generally arranged in
whorls of three and 1018cm long with an acute apex, tapered base and wavy margins
(Hardenetal.,2006).Netvenationonleafbladesisdistincton bothsurfaces, especially
when held up to the light. Petioles are 214mm long.
Flowers: Theflowers arecreamy brownishhavingsepalsthatare79mmlong~ flowers
have been observed in July and September.
Plant: The trees are perennial with 6 m tall, with brown branchlets dotted with raised
lenticels (Hauser and Blok, 1992).
Leaves: The leavesare simple, narrow oblong to narrow elliptical leaves are arranged
and the base tapers to petioles 3 to13mm long (Stanley and Ross, 2002).
Flowers: Axillary pinkish flowers are arranged in brush like hanging racemes 420 cm
(Hauser and Blok, 1992).
Fruits: Compressed rounded fruits are greyish, 1.52cm long with a hard inner shell
radicals) and not edible.
Plant: Tree is a perennial 18m tall, with greyish brown branchlets dotted with pale
elongated lenticels (Hauser and Blok 1992).
Leaves: The simple oblong lanceolate leaves are arranged in whorls of three to four,
620cmlongand24cmwide.Bladetipsarepointed, marginssharplyserratedandpetioles
are 28m long (Stanley and Ross 2002). New leaves of M. tetraphylla are bright red in
colour, whereas those of M. integrifolia are light green.
March (Hauser and Blok 1992).
Fruits: The fruit are compressed rounded with greyish green, 23.5cm wide with a hard
inner shell protecting the nut. The seed kernel is edible and not cyanogenetic.
6.1. Beaumont(Dr. Beaumont)
It is a hybrid (Macadamia integrifolia x M. tetraphylla) commercial variety, widely
Itishighin oil,butisnotsweet. Newleavesarereddish,flowersarebright pink,borne
on long racemes. It isone ofthe quickest varieties to come into bearingonce planted in
theorchard, usually carrying a useful crop by thefourth year, and improving from then
on. It crops prodigiously when well pollinated. The impressive, grapelike clusters are
sometimes so heavy they break the branchlet to which they are attached. In commercial
orchards, it has reached 18 kg nuts per tree by eight years old. On the downside, the
macadamias do notdrop from the tree when ripe, and the leaves are a bit prickly when
ofmostcommercialvarieties.Shellmediumthick,kernel40per centofnut,witha high
percentage of GradeA kernels.
6.2. Burdick
M. tetraphylla. Originated inEncinitas, Calif. Large nut, averaging 40 per pound. Shell
thin,about1/16 inches thick, well filled. Kernel recovery averages about 34 per cent of
total nut weight, quality good. It matures in October. Tree bears annually. Not widely
planted these daysand has been replaced by better cultivars. Also usedas a rootstock.
6.3. Cate
M.tetraphylla.Originatedontheproperty ofWilliamR.Cate, Malibu,California.Nuts
mediumto large.Shellwithaverage thickness.Kernels40percentofnut,creamcolour,
over a period of 6 to 8 weeks. Tree precocious, moderately hardy, shows no alternate
bearing tendency. The most widely adapted cultivar for commercial use in California.
6.4. Dorado
Originated in Australia. Imported into California by E. Westree. Thin shells. Kernel
veryquickly,is veryproductive,andhas arelativelythinshell.Varietyhavetendencyto
drop nuts year round. 
6.6. James
about 1 inch in diameter. Kernel averages 40 to 42 per cent of nut, quality high, flavor
very well, oil content 75 per cent. Tree very tall, columnar, precocious, often producing
60 or more pounds per tree when mature.
6.7. Keaau
M.integrifolia.OriginatedinLawaiValley, Kalaheo,Kauai,Hawaii. Medium sizednut,
vigorous,upright, veryproductive.
M. integrifolia. Originated in Kona, Hawaii by W.B. Storey. Medium to large nut,
averagingabout54nutsper pound.Shellveryslightlypebbled,mediumthick.Kernel37
short,withmostofthecropmaturing within about3months.Treevigorous,yieldswell,
extremely resistant to anthracnose.
6.9. Vista
nut, 3/4 to 7/8 inch in diameter. Kernel averages 46 per cent of weight of nut, flavor
excellent, oil content 75 per cent. Shell very thin, can be cracked in an ordinary hand
cracker. Tree medium sized, pyramidal, begins to bear after 3 years. Self harvesting.
Flowers pink. Recommended for both home garden and commercial plantings.
climates, particularly near the ocean. Also yields good crops in the inland.
6.11. PA39
95percentGradeAkernel,witha crackoutof40percent.Anothergreat virtueisthat
the nuts drop when ripe. It combines well with Beaumont as a pollinator. It is a small
Piper’s selections.
6.12. GT1
extra feeding. The nut is small and of good quality, with a high oil content. The kernel
6.13. GT2
AGordonTitirangi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.
6.14. GT201
A GordonTitirangiselection, usefulas a pollinator for Beaumont, has goodnutquality.
6.15. GT207
AGordonTitirangiselection.Beverlyhasonlyjustplantedthisvariety, has100per cent
grade1 nut at Woodhill.
6.16. Own Choice
Beaumont, and appears to be largely self fertile on theirorchard.Another good variety
for the domestic garden with good self or cross pollination, large nuts and few prickles.
Tends to crop inconsistently and year round not of much use commercially.
A pure M. tetraphylla varietyfrom Australia, is cultivated for its productive cropyield,
flavor, and suitability for pollinating ‘Beaumont’. Seven year old trees produced 75 kg.
6.18. Nutty Glen
AnAustralian hybrid selection. The nut is large and of good quality also popular as a
6.19. Nelmac I
It is quite a light cropper, a 10 year old tree yielding an average of 8 kg. It is a month
lateinflowering,whichmaybehinderingitspollination effectonBeaumontanditsown
cropping. However,if thepollination couldbecorrected,itwouldbeaverygood variety
because the nuts drop when ripe. Although the nut is slightly elliptical which makes
cracking awkward, and has a low crack out because of the thick shell, processors like
and high oil content.
6.20. Nelmac II
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 ear ly summer when the treeis under stress. 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 uncooked relish the taste. The nut
The crack outpercentage is high. Ten year old trees average 22kg per tree.
6.21. Renown
A M. integrifolia / M. tetraphylla hybrid, this is a rather spreading tree. It is high
droptothegroundhowever itisthickshelled,andwithnotmuchflavour.Itisoftenused
7.1.Seed propagation
Select fresh, medium sized seeds fromthe elite trees. Soak the seeds in waterfor 1 day
and discard the floating ones. Seedswill germinate after8 weeks of sowing at high soil
temperatures (30 – 35
C) and moisture levels (90 %). When temperature falls below
it avoids water logging. Harden the seedlings before transplanting to the main fields.
Seedlings take 8 to 10 years for start commercial bearing.
7.2. Vegetative propagation
graft,tip,wedgeor cleft.Graftinghas tobedonein springorautumnforbetter results.
Thescionwoodas M.integrifoliaispreferred forthebestnutsproductionandrootstock
is M. tetraphylla for its resistance to diseases (trunk canker and anthracnose). The
rootstock tobeused forgraftingshouldbeusuallyseedlingsof 912months oldwithat
leastadiameter of11.3cm.Somegrafted varietiesofmacadamiasbeginbearingwithin
2years, while others not before 7 to 8years.
of disease free plants, ease of propagation and uniformity in plants. Micropropagation
type plant in macadamia nut. Bhalla and Mulwa (2001) developed an efficient micro
propagation system in macadamia nut which would be valuable in facilitating quicker
were exposed to different levels of BA (0, 0.5, 1, 2, 4 and 8 mg l
). The developing
shoots were subcultured every four weeks and the new shoots exceeding 15 mm in
length were taken for studying rooting experiments and the number of shoots produced
per explant in every treatment. OptimumBA level (2 mgl
) fromthe above experiment
wascombinedwithvarying concentrationsofGA3(0, 0.125,0.25,0.5,0.8and1.0mg
l1) to determine an optimum shoot elongation treatment. The regenerated shoots were
Bud break and shoot numbers were significant reduced in the lowest (0.5 mgl
) and
higher (4 and 8 mg l1) concentrations of BA tested whereas budresponse and shoot
growth was recorded highest percentage in the medium containing 2 mgl1 BA. Bhalla
and Mulwa (2001) observed increasein shoot lengths with increasing concentrations of
1 BAwasobtained.
These shoots were used for rooting experiments. In vitro rooting experiments showed
very inconsistent results due to high incidences of shoot tip necrosis.
is done to reduce tree height or to change the genotype with desirable one. Grafting is
followed for top working.
8.1.Soils and climatic requirements
Macadamia can be grown in wide range of soils but performs well in red soils rich in
manganese with well drainage, deep and fertile (organic matter). Avoid planting in poor
drained clay soils. The soil pH of 5– 6.5is suitable for growth and development.Area
receiving60120 inchesof rainfallper yearisidealandcan begrown at anelevationof
15003,500feet abovethe sealevel.Temperaturerangesfrom15
plant growth and flower formation occurs at 18
C. At higher temperatures decline in
production and quality of kernel deteriorates. At low temperatures vegetative growth is
the plants at younger age and use windbreaks like leguminous species or Silver oak to
prevent wind movement. Avoid planting in shady areas.
Before orchardselection,soil analysishas to bedoneforbetter orchardmanagement.In
some areas there are serious problem of chlorosis which is caused by deficiency of ca
and phosphate, there is need to correct it. So, if the soils are lacking calcium and
istheremake itintolevel. Digthe 60cm
3 pitsthree weeksbeforeplanting.Pits are dug
in September and October.
Planting shouldbe spacedat7mapartwithin rowwith 35 mbetweenrowsfor upright
varieties. For spreading cultivar, planting is done at 10m apart within the row with 6m
between the rows. Spacing also depends on soil, variety, climatic conditions, etc.
Remove thetop soil and mix with manure and other required manures. Select healthy
and for better standing.Apply water around the plant.
At early stages training is necessary to maintain good framework for future growth.
Macadamia produces several leaders but, need to leave only strongones and rest has to
be removed. The frame work for a strong, wellbalanced tree can only be established
while the tree is young. Remove shoots growing in rootstocks where grafts are used. It
is desirable to have a spacing of ½ to 2 feet between sets of main branches. Remove
the flowers tillplant attains good stature.
Pruning of matured macadamia trees is very important to reduce the amount of
months ofJuly toAugust. Ifthereis nolateralbranchesaftertwoyears ofplanting, the
head of the tree should be pruned at least 80cm high. Prune the abnormal, pest and
disease infects branches.
8.6. Intercropping
Atearlystages ofplanting intercropscan growinbetween space.Althoughmacadamia
results with irrigation(Perdona et al., 2015).
8.7. Irrigation
Properand regularirrigation hastobegivenat earlystages ofgrowthanddevelopment.
waterstress willbethere.ThecriticalstageofirrigationisfromthebeginningofAugust
until the end of November. Over irrigation from May to July may hinder flowering.
Provide timelyirrigation basedonsoilconditionto getquality andquantity yield.
8.8. Weeding
Weeds compete for water, light, space, nutrients and also harbor pests and diseases.
Therefore timely remove weeds either manually or mechanically. By adopting drip or
basinirrigationsystem therewillbereducedweedgrowthandhighwater useefficiency.
Organic and inorganic mulch can be applied but organic one is economical. Mulching
suppresses weed growth, retains moisture, maintains micro climatefor microorganisms
and also acts as cushion while harvesting fruits. Dry and chopped grass, crop residues
of 10 to15cm from the stem and the thickness shouldbe 1015cma gain. Barner grass,
macadamia husks, fowl manure and bagasse mulch were compared in a demonstration
trial under 10yearold trees with macadamia decline symptoms. It showed that
root growth and improved tree health (Anon., 2013).
8.10. Frost Protection
over a frame around. As the trees get larger, they are more difficult to cover, but they
also become more tolerant of mild frosts.
8.11. Fertilizer management
the stem. This fertilizer should be applied following rains. In case of non rainy period
artificialirrigationhas tobegivenafterfertilizerapplication.N.P.Kshouldbeappliedin
analysis provides clear indication of nutrients requirement.
Option1 Option2
Ageoftree CAN Triple Muriateof Compound Muriateof
(Year) superphosphate potash (15 520) potash
1 100 2 0 125 185 6 5
2 200 4 0 250 370 130
3 300 6 0 375 555 190
4 400 8 0 500 740 260
5 500 100 625 925 320
6 600 120 750 1,110 380
7 700 140 875 1,295 45 0
8 800 160 1,000 1,480 51 0
9 900 180 1,125 1,665 57 0
10 1,000 200 1,250 1,850 630
11 1,100 220 1,500 2,035 700
12 1,200 240 1,625 2,220 760
13 1,300 260 1,750 2,405 830
14 1,400 280 1,875 2,590 890
15 1,500 300 2,000 2,775 950
16 1,600 320 2,000 2,960 1,020
(Source: Anon.,2012)
Macadamianut isinfestedbyvariouspestduringitlife cycle. Forbettermanagementof
pests are infesting the tree at three different stages
A. Floweringstage:FlowersaredamagedbyBlackcitrus aphids(Toxopteraaurantii),
Broad mite (Polyphagotarsonemus latus), Blue butterfly (Morpho peleides), and
Loopers (Anacamptodes fragilaria). The pests can be controlled by insecticides
like Endosulfan 35EC, Propineb 50 EC, etc.
B. Fruit formation stage: At this stage Yellow spotted bug (Bathycoelia rhodaini),
EC, etc.
C. Nut maturity stage: Macadamia nut borer (Cryptophlebia batrachopa), False
codling moth (Cryptophlebia leucotreta), Litchi moth (Cryptophleabia peltastica)
and carob moth (Spectrobates ceratoniae) are important at nut maturity stage. The
pests are controlled by insecticides like Cypermerthrin 20 EC, etc.
8.12.2. Stinkbugs
InAfrica,stinkbugsarethe mostimportantpeston macadamias causinglossesupto80
typesare: twospottedstinkbug,greenvegetablestinkbug, smallgreenstinkbug, coconut
can be controlled chemically through cypermethrin and endosulfan. For reduction of the
Majorly stinkbugs have four generations per year and each generation causes a
different type of damage to the nuts.
S.No. Stinkbugsgeneration Occurrence Damageofplantpart
1 Springgeneration AugusttoSeptember Occurduringorafterfloweringand
canc auseextensiveflowerandfruit
2 Summergeneration Decembe r Itcausesdamageatthetimeoffruit
3 Autumngeneration FebruarytoMarch Itmainlyfeedson then utsbefore
an d dur ing  harve st. Altho ug h it
4 Wintergeneration Dec ember endtoJan uary Itd oesn’tcauseprob lemsbecause
an d alsotheya re no t veryactive
du ring th isseaso n
8.12.3. SouthernGreen Stinkbug (Nezara viridula)
Itsattackleadstoprematurenutdropandkerneldamage.Thestinkbuginserts itshollow
feeding activity causes pitting of the kernel. Nuts infested on the ground may also have
white or brown discoloring. The damage can be seen year round but majorly damage is
observed from July to September. The variation in infestations is due difference in
environmental conditions. The stinkbugs reproduction and development stages occur on
It can be control by spray of endosulphan and malathion.
8.12.4. Litchi FruitMoth (C. ombrodelta)
It bores into the nut causing premature nut fall and damaging the kernel. Nut quality is
diminished and production is decreased. The damage mainly occurs during the oil
accumulation period whereas the insects are prevalent yearround. Heavy premature nut
drop results from May to mid of the August. It effectively controlled by spray of
8.12. 5. Red‐banded thrips (Selenothrips rubrocinctus)
nutdrop ornutquality. Insevereinfestationbronzingsymptomappears ontheleaf. Pest
pressures from this pest may be greater at lower elevations. It mainly occurs in end of
theharvest season,butthey arepresentin orchardsyearround. Inthenursery itaffects
growth duringthe firstsixmonthswhereseedlingheightwillbe1012 inches tall(when
growth is normally slow). It can be chemically controlled by malathion.
8.12.6. Red& Black Flat Mites (Brevipalpus phoenicis) & Broad Mites
(Polyphagotarsonemus latus)
Thebothflatandbroadmitesareabundantlyfound inmacadamiagrowingareasfeeding
The infection by broad mites results in silvering of husks whereas flat mites results
bronzing of husks. T hey can be chemically controlled by spaying with Microthiol.
8.12.7. Hawaiian flower thrips(Thrips ha waiiensis)
The secondary pests which are commonly foundin macadamia nut are broad mite, red
and flat mite. The secondary pests’ seriousness varies dramatically in orchards due to
abnormality in cultural practices (fertilizer application and pruning), weather conditions
8.13.1.MacadamiaRootRot(C.O.Armillariella mellea)
Due tothe soil borne nature of fungus, the infectionstarts fromthe root system which
later extends toward upwards resulting into complete deathof the plants. Root rottening
tree totree occurs by root contact. The temperatures varyingfrom 8
C to 22
C along
with wet soils having a high proportion of woody debris facilitates rapid spread of the
fungus and again. Before digging holes for planting, all woody roots debris must be
removed and burnt.
8.13.2. Blossom Blight (C.O. Botrytis cinerea)
8.13.3.Anthracnose(C.O.Glomerella cingulata)
The fungal pathogen mainly affects the leaves, twigs and the nut. Leaves dropping and
die back of the twigs takes place with the advancement of the disease. The disease is
spread by wind and infected leaves and twigs whichfall of the plant acting as a source
leaves may results in control of the disease.
8.13.4.Huskspot(C.O. Pseudocercospora macadamiae)
Initially chlorotic to yellow flecks symptom appear on the husks which enlarge and
develop tan brown in the centres. Later the lesions coalesce and develop diffuse bright
yellow halos and may develop inside the husk but shells and kernels remain unaffected.
The spores are spread from infected husks by water splash and diseased husks may
produce spores for up two years. Remove the old and diseased husks from thetree to
reduce inoculum levels.
Itisamajor disorderin macadamianut. So manyfactorslikelow organicmatter levels
insoil,deficitnutrients,drought,rootexposureduetosoil erosion, rootdeathinshallow
marginal soils, heavy crop loads, pests and diseases are responsible for this disorder.Managementpractices
Good orchard management.
Pruning – Prune affected parts to generate new flush. Apply foliar fertilizers at
regular intervals for new leaves.
for pests and there may be chancesof trunk canker infestation and pest attack.
Applyrecommendeddoseoforganicandinorganicfertilizers, andgoforregularsoil
and leaf analysis.
To prevent soilerosion, adapt drip or channel irriga tion system for watering.
Avoid planting inshallow lands or after mounding go for planting.
Regular checking and management of pests and diseases.
8.14.2. Abnormal vertical growth (AVG)
has observed in dry areas of Queensland and New South Wales, and deep well drained
red soils. HAES 344 is the most susceptible variety.
Symptoms – Upright branch growth, reduction in flowering which leads to low yield.Managementpractices
Avoidplantingindryregionsoraftercorrectingthe possiblefactorslikelimitwater
infiltration,water r etentionand root growthgo for planting.
Avoid planting susceptible varieties or plant spreading varieties.
Maintainoptimumsoilconditions, regularapplicationofmanures andfertilizers.
8.15.Use of plant growth regulators
8.15.1. Auxin
Gibberellins also play important role in flower and fruitdevelopment, and fruits often
contain highlevelofendogenousgibberellinconcentrations(Wilkieet al., 2008;Ayeleet
al., 2010). Trueman, (2010a) found that immature macadamia fruits contain very low
3 applicationwhichtendstoindicatethat theprocessesinvolved
in macadamia fruit retention are not sensitive to gibberellin concentrations
8.15.3. Cytokinin
growth regulators have been tested for their ability to reduce abscission of macadamia
flowers and immature fruits but only the cytokinin, benzyladenine(BA), has shown any
promise of increasing fruit retention (Williams, 1980; Trueman, 2010a). The cytokinin,
benzyladenine, increases fruit retention for up to 8 weeks after anthesis but does not
2010a).Endogenouscytokininlevelsareveryhighinmacadamia fruitsaround10weeks
toapplied cytokininsatthisstage(Trueman,2010b).
The benefits resulting from Ethephonreduced harvest lengthand time, lesspressure on
(Jim and Kevin . 2012).
Nagao et al. (1999) studied the effectof uniconazole (0.2 g a.i. per cm trunk diameter)
on 2 yearold potted macadamia (Macadamia integrifolia Maiden & Betche) trees and
they found that uniconazole significantly reduced tree height and trunk diameter 1 year
after initial treatment, and suppressed shoot extension for the duration of the study. In
st year but in 2
nd year in treated plant there was increase in flowering as compare to
untreated plant. Subsequently, no differences in flowering were observed until the fifth
and trunk growth and tip dieback.
For better quality, macadamia nut kernels should have light cream colour, spherical in
shape, high oil content, free from rancidity, decay, insect damage, blemishes and
discoloration. Highest quality kernels contain 72 to 78 per cent oil and 1.5 per cent
moisture whereas for fully developed macadamia kernels should contain 72 per cent oil
ormore. Oilcontentisamajor qualityfactorwhichvariesfromcultivarto cultivarand
The rapid drying, oil content and electrical impedance of the nut are the other maturity
indices of the macadamia nut. Sometimes shakeharvesting is employed to facilitate the
harvest while minimizing the amount of immature nuts are harvested.
Macadamia nuts are mainly ready for harvest during late May to July, but variety to
varietyit varies alsoand it maygo onunto late November. Nuts are picked byhand or
sweptup mechanically from the orchard floor, depending on the variety of tree.A long
good tree will produce 3050pounds of nuts at 10years age and gradually increase for
many years. If mechanically harvesting, attention needs to be paid to the efficiency of
harvesting machinery and the evenness of the soil surface. Harvest containers and
machinery equipmentmust be cleaned before use otherwise it mayincrease the risk of
contamination of the nuts and also risk of spreading diseases.
11. YIELD
Orchards in New Zealand have returned yields of 46 tonnes per hectare (http://macadamias). In optimum conditions an 8 year old tree
isAustralia with40%of total worldproduction.The United States isthesecondlargest
producer followed by SouthAfrica, Guatemala, Brazil and Costa Rica. In the United
States, Hawaii dominates production with 95% of domestic macadamia nut production.
Treeage 5 6 7 8 11 25
Treeyield(Kg/tree) 2 5 8 10 1 5 55
12.1. Dehusking
Dehusking the macadamia nuts must be done within 24 hours of harvest, after which
followed by the drying process. Freshly fallen nuts contain about 25 per cent kernel
moisture,althoughnutsthat haveremainedonthegroundfor extendedperiodsmayhave
as little as 10 to 15 per cent moisture.
12.2. Drying
Theobjectofdryingismainlytoproducenutsfirm, crisp, lightin colourand freefrom
blemishes. Drying should begin with ambient air, followed by a gradual increase in
Catthe finalstageofdrying.Themoisture content
the nuts in onion sacks for 8  12 weeks depending on the ambient temperature and
humidity. It is necessary to protect the dry kernels from moisture and oxygen because
dryer the nut, higher the quality and net return.
12.3. Storage
The hard, unshelled nuts have protection against insects during storage whereas the
kernelsofshellednutsare susceptibleto infestation. So it wouldbebettertostore them
unshelled. The shelled nuts must be kept in cold storage because they are susceptible to
insect damage.They canthenimmediatelybe placedin a coldstore at 0 to 4 °C. Cold
storage prevents fungal growth and rancidity. This method is also recommended for the
storagebut mightbedesirableforextendedperiods.Frozenstorage(18°C)canbevery
effective in extending shelflife.
The nuts should be packed into cartons as soon as possible after shelling. Packaging is
the final taste of the nuts, and also increases theshelf life.
andgradesforshelledmacadamianuts,inshellmacadamianuts,and roastedmacadamia
nuts (Hawaii Department ofAgriculture 1984). The standards grade consists of eight
StyleI  Wholes
Style II  Wholes and halves
Style III  Cocktail
Style IV  Halves and pieces
Style V  Large diced
Style VI  Chips
Style VII  Bits,dice
Style VIII  Fines
lb) vacuumpacked or nitrogenflushed foil bags but sometimes larger nitrogen flushed
containers are used.
Thekernelisthemainproductfromthemacadamianuttree.Macadamia nutkernelsare
mainly used in confectionaries including chocolate bar, chocolate covered candy, ice
cream and other baking products. Macadamia nut kernel are also used for making
macadamia butter and also used in the form of roasted/fried kernel and snacks. The oil
produced by macadamia nuts can be used for cooking and in the long term could be
sunscreens, soaps and others.  The shell and husk also have uses. Shells can be used as
fertilizer(aftercomposting)andmulchwhereastheremainingpresscake canbe usedfor
animal feed.
Thedomesticmarketconsumesabout35%oftotal production,90%ofwhich issoldas
new market penetration, is expected to underpin furtherindustry growth. In 2013 kernel
exports were spread relatively evenly between the USA, Japan, Europe and other Asian
markets. Asian markets are showing the greatest growth driven by increasing trade
interest and consumer awareness. In the last few years market development campaigns
have supported the product in Taiwan and Korea. On the basis of Geographical region,
Eastern Europe,Asia Pacific excluding Japan and Middle East andAfrica (Table 4). In
present North America and Western Europe had higher market share for macadamia.
Theglobalmacadamiamarketonthebasisofapplicationis broadlysegmentedintofood
S.N. GlobalMacadamiaMarketRegions Countries
1 NorthAmerica USandCanada
2 LatinAmerica BrazilandArgentina
3 W esternEurope EU5,Nordicsan dBenelux
4 AsiaPacific Aust raliaand New Z ealan d (A NZ ), G re ate r
5 MiddleEastandAfrica GCCCountries,OtherMiddleEast,NorthAfrica
Inpresentcompaniesareinvestingthroughpromotionalactivitiesin ordertoincrease
the footprint of macadamia worldwide. So there is a high potential to increase share of
marketof macadamiaintermsof revenue incountries likeMexico,China, SouthAfrica
and others. The key element in global macadamia marketare Mauna Loa Macadamia
Nut Corp., Hamakua Macadamia Nut Company, Wondaree Macadamias, MacFarms,
NAMBUCCA MACNUTS Pty Ltd, Golden Macadamias, Kenya Nut Company Ltd.,
Royal Macadamia (Pty) Ltd. and MWT Foods Australia.
In 21
st century, climate change is the greatest concern in macadamia as well as in
attackofpest andseriousdisease. Theeffectofchangeinclimateareglobalwarming,
drought, excessiverain,meltingofice,changeofseasonalpattern,flood,rising sealevel
etc.leadingtodecreaseinyieldpotential.Theairtemperaturefor growingofmacadamia
high temperature in macadamia nut results into leaf damage, bud damage and dieback
whereas; if low temperature doesn’t met as the requirement floral initiation is affected.
Duringdroughtfloweringresults intoreducedwater potentialin racemescauses damage
nut drop and less percent of kernel development. Climatic conditions are also having
To increaseproductivityand qualitynuts.
To make available planting material commercially.
Reduce the crop lossesdue toimmature nuts and moldy / rotten nuts
To solve the problem of inadequate valueaddition and processing.
To develop the variety resistant to biotic and abiotic stress.
Use of molecular techniques for germplasm characterization and marker assisted
selection should be a highpriority.
Useofbiotechnologytoolsapplicationsshouldbeprioritizedtoyield maximumpractical
benefits in the shortest possible time.
in macadamia nut cultivation. The main form of organic fertilizer used in macadamia
before use in an organic orchard. Composting will reduce the levels of food pathogens
toacceptablelevelsanddestroy antibioticresidues.Beforestartingorganiccultivation of
abiotic stress. Mowing must be undertaken down and across the rows, especially when
(example(for sting bug trap crop used are triticale, vetches and crimson clover) is also
and which lures the pests away from the macadamia crop.
Anonymous, 2012. Chindikani Kaseka Nyirenda,(20 12). Ma cadamia in Malawi its pest
and. html? view= magazine. (Jan24).
Anonymous, 2013. Reducing erosion and other soil degradationin macadamia orchards
Agnote DPI331, Second edition, 16 Jan 2003 (NSW Dept. Primary Industries)
profileduringChristmasrose(Helleborus nigerL.)flowerandfruitdevelopment. J.
Plant Growth Regul., 29: 194209.
Horticultural Reviews, 32:167–228.
InI International Symposium on Acclimatization and Establishment of
Micropropagated Plants 616(pp. 343346).
Costello, G., Gregory, M. and Donaitu, P. 2008. Southern Macadamia Species Recover
Plan 20082012. Report to Department of the Environment, Water, Heritage and the
Arts, Canberra by HorticultureAustralia Limited, Sydney.
Darlington, C. D., and WylieA. P. 1955.Chromosomeatlas of flowering plants. George
Allen & Unwin Lrd., London.
Agency, Brisbane. Exp. Sta. Prog. Notes, 51. 6 pp.
Harden,G.,McDonald,B.andWilliams,J.2006. RainforestTreesand Shrubs: AField
Guide to their Identification. Gwen Harden Publishing, Nambucca Heads.
Hardner, C. M., Peace, C.P. Henshall, J. and. Manners, J. 2005. Opportunities and
Hauser, J. and Blok, J. 1992. Fragments of Green.Australian Rainforest Conservation
Society, Brisbane.
JimPatchandKevin Quinlan.2012.Ethephonandits useonmacadamianuts.Website: MPC Growers SiteAn Online Resource For Our
Macadamia Growers.
Nagao, M.A.,Hoa, E. B.,&Yoshimoto, J. M. 1999. Uniconazole retards growtha nd
increases flowering of young macadamia trees.Hort. Science,34(1), 104105.
Peace, C.P., Vithanage, V.,Turnbull, C.G.N. and Carroll, B.J. 2003.A genetic map of
macadamia based on randomly amplified DNA fingerprinting (RAF) markers.
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ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Cytokinins play a central role in fruit set and development, with many plants accumulating high concentrations of endogenous cytokinins in developing fruits, and applied cytokinins being used to induce fruit set or parthenocarpic fruit development. Cytokinin application to flowers or immature fruit of macadamia increases initial fruit set and delays fruit abscission, without affecting final fruit set. This study quantified and determined the timing of endogenous cytokinin accumulation in macadamia flowers and immature fruit, to assist in developing a cytokinin treatment to improve fruit set and kernel quality. Flowers and very young fruit contained little cytokinin but levels rose greatly between 3 and 10 weeks after anthesis. Zeatin and zeatin riboside were the predominant cytokinins at 10 weeks post-anthesis, with zeatin riboside concentrations being 20 -230 times higher than concentrations detected immediately after anthesis. Cytokinin accumulation coincides with the period of maximum endosperm volume in macadamia which, along with the predominance of zeatin and zeatin riboside, conforms to the general pattern of accumulation in developing fruits of many other plants. The very high cytokinin concentrations at this stage may explain the inability of pre-or post-anthesis cytokinin applications to increase fruit retention of macadamia beyond 10 weeks post-anthesis.
Full-text available
Macadamia is a mass-flowering subtropical rainforest tree that is widely cultivated for its edible kernels. Macadamia flowers are borne on pendant racemes of 100 -300 flowers but typically less than 2% of the flowers produce mature fruits and kernels. This study investigated the use of plant growth regulators to reduce abscission of flowers and immature fruit and to increase final fruit set of Macadamia. Pre-anthesis applications of the cytokinin, benzyladenine at 200 mg/L, increased initial fruit sets (2 weeks after anthesis) across four experiments from 8 -17% (for control racemes) to 27 -61% (for treated racemes). Post-anthesis applications of benzyladenine increased fruit retention up to 8 weeks after anthesis, but no treatment increased fruit retention beyond the final phase of immature fruit drop at 10 weeks post-anthesis. Benzyladenine delayed abscission of immature Macadamia fruit but it had no effect on final fruit set, nut-in-shell weight or kernel weight.
Full-text available
Gibberellins (GAs) were identified and quantified during flower and fruit development in the Christmas rose (Helleborus niger L.), a native of southeastern Europe with a long international horticultural tradition. Physiologically, the plant differs from popular model species in two major respects: (1) following anthesis, the initially white or rose perianth (formed in this species by the sepals) turns green and persists until fruit ripening, and (2) the seed is shed with an immature embryo, a miniature endosperm, and a prominent perisperm as the main storage tissue. GA1 and GA4 were identified by full-scan mass spectra as the major bioactive GAs in sepals and fruit. LC-MS/MS system in accord with previously verified protocols also afforded analytical data on 12 precursors and metabolites of GAs. In the fruit, GA4 peaked during rapid pericarp growth and embryo development and GA1 peaked during the subsequent period of rapid nutrient accumulation in the seeds and continued pericarp enlargement. In the sepals, the flux through the GA biosynthetic pathway was highest prior to the light green stage when the photosynthetic system was induced. Unfertilized, depistillated, and deseeded flowers became less green than the seed-bearing controls; chlorophyll accumulation could be restored by applying GA1, GA4, and, less efficiently, GA3 to the deseeded fruit. The sepals of unfertilized and depistillated flowers indeed contained very low levels of GA4 and gradually decreasing levels of GA1. However, the concentrations of their precursors and metabolites were less affected. These data suggest that a signal(s) from the fruit stimulates GA biosynthesis in the sepals resulting in greening. The fruit-derived GAs appear to be mainly involved in pericarp growth and seed development. KeywordsChristmas rose-Fruit and seed development-Gibberellin identification and quantification- Helleborus niger L.-Perianth greening
Uniconazole (0.2 g a.i. per cm trunk diameter) was applied as a soil drench to 2-year-old potted macadamia (Macadamia integrifolia Maiden and Betche) trees, and reapplied yearly for 4 additional years. Uniconazole significantly reduced tree height and trunk diameter 1 year after initial treatment, and suppressed shoot extension for the duration of the study. It significantly increased flowering the second year after initial treatment, the first year that both the control and treated trees flowered. Subsequently, no differences in flowering were observed until the fifth year, when flowering was significantly less in treated trees, probably due to reduced shoot and trunk growth and tip dieback. Chemical name used: E-1-(p-chlorophenyl)-4,-4-dimethyl-2-(1,2,4-triazole-1-penten-3-ol) (uniconazole).
The effects of NAA application, cincturing and shoot-tip removal on the incidence of premature fruit drop were investigated in orchard-grown trees of Macadamia integrifolia cv. Kakea. A single, post-anthesis application of NAA (1 ppm) increased (P < 0.05) the final set of macadamia fruit by 35%. Limb cincturing combined with shoot-tip removal increased (P < 0.05) initial fruit set and possibly final set. Cincturing alone was less effective and shoot-tip removal had no effect alone.
The first genetic linkage map of macadamia (Macadamia integrifolia and M. tetraphylla) is presented. The map is based on 56 F1 progeny of cultivars ‘Keauhou’ and ‘A16’. Eighty-four percent of the 382 markers analysed segregated as Mendelian loci. The two-way pseudo-testcross mapping strategy allowed construction of separate parental cultivar maps. Ninety bridging loci enabled merging of these maps to produce a detailed genetic map of macadamia, 1100 cm in length and spanning 70–80% of the genome. The combined map comprised 24 linkage groups with 265 framework markers: 259 markers from randomly amplified DNA fingerprinting (RAF), five random amplified polymorphic DNA (RAPD), and one sequence-tagged microsatellite site (STMS). The RAF marker system unexpectedly revealed 16 codominant markers, one of them a putative microsatellite locus and exhibiting four distinct alleles in the cross. This molecular study is the most comprehensive examination to date of genetic loci of macadamia, and is a major step towards developing marker-assisted selection for this crop.
The intention of this review is to discuss floral initiation of horticultural trees. Floral initiation is best understood for herbaceous species, especially at the molecular level, so a brief overview of the control of floral initiation of Arabidopsis (Arabidopsis thaliana (L.) Heynh.) precedes the discussion of trees. Four major pathways to flowering have been characterized in Arabidopsis, including environmental induction through photoperiod and temperature, autonomous floral initiation, and regulation by gibberellins. Tropical trees are generally induced to flower through environmental cues, whereas floral initiation of temperate deciduous trees is often autonomous. In the tropical evergreen tree mango, Mangifera indica L., cool temperature is the only factor known to induce flowering, but does not ensure floral initiation will occur because there are important interactions with vegetative growth. The temperate deciduous tree apple, Malus domestica Borkh., flowers autonomously, with floral initiation dependent on aspects of vegetative development in the growing season before anthesis, although with respect to the floral initiation of trees in general: the effect of the environment, interactions with vegetative growth, the roles of plant growth regulators and carbohydrates, and recent advances in molecular biology, are discussed.
This paper reviews the potential of marker-assisted selection (MAS) for breeding of macadamia. Many papers suggest MAS can be applied to breeding, but there are few reports of its implementation. The constraints to the application of MAS are reviews. The critical first step in is a comparison of alternative strategies. For macadamia, detection of associations between marker-QTL’s using multiple families linked through pedigree is the most attractive strategy. SSR markers are a pre-requisite for application in macadamia. Research is needed to evaluate the extent of linkage disequilibrium across the breeding population and response to breeding strategies with MAS.
Chindikani Kaseka Nyirenda Macadamia in Malawi its pest and diseases
  • Anonymous
Anonymous, 2012. Chindikani Kaseka Nyirenda,(2012). Macadamia in Malawi its pest and diseases.­in­malawi­its­pest and. html? view= magazine. (Jan­24).