Pistachio nut Production Technology

1. Pistachio Nut
Production Technology
Mandeep Kaur
Ph.D. Fruit Science

2. Introduction to Pistachio nut
– Common Names: Pistachio, Pistache.
– Related Species:
Atlas Pistache (Pistacia atlantica).
Chinese Pistache (P. chinesis).
Terebinth Pistache (P. terebinthus).
– Distant Affinity:
Cashew (Anacardium occidentale).
Mango (Mangifera indica).
Ambarella (Spondias cytherea).
Yellow Mombin (Spondias mombin).

3. Botanical name Pistacia vera L.
Family Anacardiaceae
Center of origin Western Asia
Chromosome number X = 15, 2N = 30
Conservation status Near threatened
Sex form Dioecious
Mode of pollination Cross pollination
Mechanism of pollination Anemophyllous (wind pollinated)
Type of fruit Nut
Edible portion Elongated seed
Nature of fruit Non-climacteric

4. Origin & Distribution
– The pistachio tree is native to western Asia and Asia Minor, from Syria to the Caucasus and
Afghanistan.
– Archaeological evidence in Turkey indicate the nuts were being used for food as early as 7,000 B.C.
– The pistachio was introduced to Italy from Syria, early in the first century A.D. Subsequently its
cultivation spread to other Mediterranean countries.
– The tree was first introduced into the United States in 1854 by Charles Mason, who distributed seed
for experimental plantings in California, Texas and some southern states.
– In 1875 a few small pistachio trees, imported from France were planted in Sonoma, California.
– In the early 1900's the U.S. Dept. of Agriculture assembled a collection of Pistacia species and
pistachio nut varieties at the Plant Introduction Station in Chico, California.
– Commercial production of pistachio nuts began in the late 1970's and rapidly expanded to a major
operation in the San Joaquin Valley.

5. World Pistachio Nut Production
In-shell Basis (Metric Tons)
*Source: https://www.nutfruit.org/files/tech/1524481168_INC_Statistical_Yearbook_2017-2018.pdf
 World pistachio production amounted to over 586,200 metric tons (in-shell basis),
down from the previous year, partly due to some producing countries experiencing an
“off year”.
 In spite of this, the overall production keeps growing: the last season, it was raised by
8% from the previous 10-year average.

6. Pistachio Nut Production In 2017-18
In-shell Basis (Metric Tons)
 The USA and Iran were the top producers during the 2017/2018 season,
accounting for 47% and 38% of the world production, respectively.
 Along with Turkey, they added up to 94% of the world share.
*Source: https://www.nutfruit.org/files/tech/1524481168_INC_Statistical_Yearbook_2017-2018.pdf

7. World Pistachio Nut Exports In 2016
In-shell (Metric Tons)
 Iran and the USA concentrated 68% of world exports in 2016, totaling 244,565
MT of traded in-shell pistachios.
 China accounted for 19% of shipments over the same period.
 China was the main market for the USA and Iran exports, it accounted for 58%
and 22% of the USA and Iran shipments, respectively.
*Source: https://www.nutfruit.org/files/tech/1524481168_INC_Statistical_Yearbook_2017-2018.pdf

8. Composition & Uses of Pistachio
Nutritional value per serving of 100 g *
Energy 626 K cal
Carbohydrates 16.2 g
Fat 53.5 g
Protein 19.8 g
Iron 7.7 mg
Water 5.6 g
Phosphorus 430 g
Minerals 2.8 g
Fiber 2.1 g
Carotene 144 µg
Thiamine 0.67 mg
Riboflavin 0.28 mg
Niacin 2.3 mg
*Source: Gopalan et al. 1987
– Pistachios (kernels) are highly rated
for its delicious flavor, sweet kernel
usually used as dessert, roasted,
salted, employed as an important
ingredient in various confectionary
& ice-cream, husks made into
marmalade & organic fertilizer.
– Pistachio oil used as spice oil & in
medicines.
– Leaves used for cattle feed & wood
for furniture & ornamental work.

9. Health Benefits of Pistachio
– Pistachios are cholesterol-free and high in monounsaturated
fat & helps to protect from heart attacks.
– Aids in digestion.
– Helps to cure lung cancer.
– Helps in controlling diabetes.
– Aids in weight management.
– Increases iron absorption in body.
– Helps in elimination of dryness from skin.
– Rich in antioxidant & aphrodisiac properties.
– Helps in decreasing levels of bad LDL cholesterol.

10. Tree Description
– The tree grows up to 10 m (33 feet) tall. The trees are inclined to spread and droop, and may initially need
staking. Their open habit and attractive foliage make them valuable ornamentals. Under favorable
conditions, pistachio trees live and produce for centuries.
– It has deciduous pinnate leaves, 10–20 centimeters (4–8 inches) long.
– Leaves are smooth green above light pale beneath, leathery-coriaceous pubescent when young, glabrous
later. They contain irregular glands which contain tannins that are used in dyeing industry.
– The reddish, wrinkled fruits are borne in heavy clusters somewhat like grapes.

11. Fruit Description
– Although it is known as nut, but
botanically the fruit is a drupe &
edible portion is an elongated seed.
– The outer hard, cream-colored
exterior shell of the fruit is removed
and inner seed kernel is usually eaten
as it is edible.
– Seed has a mauve-colored skin and
light green flesh, with a distinctive
flavor.
– When the fruit ripens, the shell changes from green to an autumnal yellow/red and abruptly splits partly open.
This is known as dehiscence, and happens with an audible pop.
– The splitting open is a trait that has been selected by humans. Commercial cultivars vary in how consistently they
split open.

12. Ecological Requirements
– Pistachios are generally considered as xerophytic type of plants which are able to withstand extreme
dryness of soil & air; high humidity is unfavourable for proper fruit set & development & it also increases
the incidence of diseases.
– The pistachio thrive best in areas having cool enough winter for proper breaking of bud dormancy & long
hot, dry summers for maturing of nuts.
– It can be grown on wide range of temperature from -30 ͦC in winter to 42.2 ͦC in summer without being
damaged (Whitehouse 1957).
– It needs 700-1000 chilling hours at or below 7 ͦC while Afshari et al. (2009) observed 1100-1200 chilling
hours in Damghan region of Iran.
– In Iran, it is grown at an elevation of 4000 feet, where annual rainfall averages 10-15 inch in a year &
summer temperature reaches to 100 ͦF.
– It thrives best on deep, light or dry sandy loam with high moisture content & are probably more tolerant
to alkaline & saline soils (Tous & Ferugosun 1996).

13. Species of Pistachio
– Zohary (1952) recognized 11 species in the genus Pistacia on the basis of leaf characters,
while Al-Saghir & Porter (2006) reports the genus contains 9 species & 5 sub-species.
– Only Pistacia vera produces the commercially acceptable nuts, while other species serves as
rootstocks of ornamental trees.
– Pistacia atlantica & Pistacia terebinthus bears small sized nuts which are consumed locally &
used for oil extraction.
– Pistacia lentiscus is used for obtaining high grade resin & mastic.
P. atlanticaP. terebinthus

14. Commercial cultivars of Pistachio
Country Most popular cultivars
Iran Owhadi, Momtaz, Safeed, Wahedi, Agah & Kaleghoochi.
Turkey Uzun & Kirmizi.
Syria Alemi, Obaid, Mirhavi, Achoury, Aintab & Ashoori.

15. Iranian cultivars
Momtaz
 The fruit is round,
thick and yellowish.
 Very appreciated in
Iran.
Kerman
 It produces exceptionally
large nuts with excellent
kernel quality.
 Trees have pronounced
alternate bearing tendency
& having high yields.
Peters
 It is considered universal
pollinizer because it sheds
pollen while many females
cultivars are receptive.

16. Turkish cultivars
Uzun Tu
 Pistachio nut of
average size, long
and clear green.
Kirmizi TU
 Pistachio nut of
average size and
reddish colour.
 Along with the
cultivar Uzum, it is
the most cultivated
variety in Turkey.
Abiad miwahi
 Pistachio nut of average
size, white colour and
excellent quality.

17. Syrian cultivars
Achoury
 Pistachio nut of
average size, red
colour, excellent
quality and very
productive.
Elbataury
 Thick fruit of
whitish colour
and good
quality.
Ayimi Obaid Alemi

18. Aegina
 Medium size fruit, long
and similar to ‘Mateur’.
 It came from Greece
and it also gives good
results in Spain.
Mateur EU
 Long fruit, average size,
yellow greenish colour and
good taste quality.
 It was selected in Tunis
and it gives good results in
Spain.
 In Castilla-La Mancha, it
ripens at the end of
August.
Larnaka
 Average size pistachio,
less long than ‘Mateur’.
 Original from Cyprus.
 It is cultivated in Greece
and in Spain, giving
good yield.
European cultivars

19. Rootstocks of Pistachio
– The most common rootstocks used in California pistachio orchards are Pistacia atlantica &
Pistacia integerrrima (also known as Poineer Gold I).
– Pistacia integerrrima is less susceptible to Verticillium wilt whereas Pistacia atlantica is more
susceptible.
– Pistacia atlantica is more cold hardy than Pistacia integerrrima.
– Poineer Gold II is a new hybrid, it is resistant to Verticillium wilt & has cold hardiness.
– UCB 1, a new cross between Pistacia integerrrima and Pistacia lentiscus, developed by
University of California. It is more vigorous rootstocks than other rootstocks & resistant to
Verticillium wilt as well.
– Pistacia chinensis is susceptible to cold winters & it is not compatible to Pistacia vera.
– In Mexico, Pistacia terebinthus has been more cold tolerant than Pistacia atlantica. It is slow in
growth but once established, grows better than the latter.

20. Propagation by seed
– Seeds need to be stratified to make them germinate.
– Stratification involves soaking the seeds for about 3 hours in cool water.
– Put seeds in a mixture of sand and peat moss and store in a refrigerator for 6
weeks at about 40° F.
– Stratification may not be needed for easy-to germinate species like P. atlantica.
– Just wrap seeds in moist burlap and put them in a cool dark place until they
germinate.
– Seeds should be inspected often because the seeds need to be planted soon
after sprouting.

21. Propagation by T-budding
– Established seedlings (3/8 to 1/2 inch in diameter) should be budded in the fall.
– Depending on planting time and seedling size, seedlings can be budded the same year they
are planted or the following year. Experience has shown current-year bud wood increases
the bud take dramatically.
– T-budding is the most common propagation method. Buds usually are placed on the
windward side.
– Seedlings (rootstocks) must be growing vigorously to get a good percentage of bud take.
– Ample, but not excessive, moisture before and after budding improves chances for a good
bud take. This requires good irrigation practices to keep the soil moist.
– Buds can be forced into growth 2 to 3 weeks after insertion, either by heading back the top
seedling to 2 inches above the bud or by ringing just above the budding section.

22. Micro-propagation of Pistacia Cultivars
Micro propagation of Pistacia
a) Shoot formation from the forced apical shoot tips
of P. vera L. cv. Atli cultured on the culture
initiation medium after 4 weeks of culture (Tilkat et
al. 2013).
b) Shoot proliferation from in vitro-derived leaf
explants of pistachio, P. vera L. cv. Siirt (Tilkat and
Onay 2009).
c) Rooting microshoots of P. vera L. cv. Atli on
modified MS Medium (Tilkat et al. 2008 a).
d) Plantlets acclimatized from microshoots following
establishment in a mixture of sterile compost
(soil:peat, 3:1).
*Source: https://www.researchgate.net/publication/321201089

23. Spacing and Planting Procedures
– A good planting system seems to be spacing the trees 12 feet apart in rows spaced 24 feet apart.
– Pollinator trees are planted every third tree in every direction, always having two rows without
pollinators. This puts a pollinator in the center of a nine-tree rectangle, and growers can plant 150
trees per acre with- 16 pollinator trees.
– Pistachio trees grow slowly and removal of temporary trees (every other row) will not be needed
for 15 to 20 years.
– After tree removal, final tree spacing will be 24 × 24 with 75 trees per acre, including 8 pollinator
trees.
– Pistachios do not tolerate crowding. Lower branches die out as soon as trees are being shaded.
– Yields go down because the photosynthetic area is reduced, which decreases the cropping surface
of the canopy.
– Removing pistachio trees in alternate rows should be done as soon as lower branches start dying.

24. Flowering Physiology
– Pistachio is a dioecious fruit species, that the pistillate & staminate flowers are formed on different
trees.
– The male flowers are with 2 bract lets at the base & 1-2 sepals, 3-5 stamens with short filaments.
– The female flowers have 2-5 sepals, superior ovary, sub-globose or ovoid with 1 ovule with short
styles.
– Both pistillate & staminate inflorescence form panicles with several hundred individual flowers
(Crane & Iwakiri 1981) & generally bloom in the first fortnight of April.
– Both types of flowers are apetalous. Numerous flowers are present on central axis of inflorescence.
– Floral buds remain vegetative during early 4-5 years of growth periods which then develop into
floral buds as the tree passes into productive phase.

26. Pistillate flower
Staminate flower

27. – The pistachio is a dioecious tree, meaning male and female flowers are produced on
separate trees.
– Insufficient pollen is a primary cause of crop failure.
– One male (pollinator) tree for 8 to 10 female trees (producer) is recommended.
– A good orchard layout will be to plant a pollinator in the middle of a nine-tree block
throughout the entire orchard.
– Border rows on the upwind side should be planted with pollinators, too.
– Female flowers do not have nectar & petals that could attract bees for insect pollination.
– Pollen transfer depends entirely on the wind.
– About 10% of flowers generally set fruits in which 7.5% contain kernel & 2.5% are blank
(Crane 1986).
Pollination

28. Training & Pruning of Pistachio
– Plants are generally trained to modified leader system with 3-4 primary scaffold
branches at 30 cm spacing on the trunk.
– The lower scaffold branch is kept about 1 m above the ground.
– New branches which are more than 75 cm long should be pinched to encourage
lateral growth (Woodroof 1979).
– Trees are long lived but grow relatively slowly as compared to other deciduous
trees & do not make dense top.
– A well trained tree needs only light pruning afterwards.
– Since pruning wounds heal very slowly, so large cuts are to be avoided.

29. Nutrition Management
– Nitrogen is one of the most likely plant nutrients to be deficient in pistachio orchards, & low levels may
affect both leaf production & nut yield potential.
– The normal range of nitrogen in pistachio leaves appears to be 2.5-2.9% dry weights in August (Beede
1994). Levels below 2.3% are likely to be associated with symptoms like nitrogen deficiency, including
delayed bud break; thin shoots, with reddish bark etc.
– Nitrogen is usually applied to the soil 4 times annually, over March through July period.
– A recommended application rate is 1 pound of nitrogen per tree annually, which is about the amount
removed by a moderate sized (1500 pounds per acre) nut crop.
– Boron, zinc & copper are other nutrients that are deficient in pistachio orchards.
– Foliar application of zinc & copper after every 2 seasons, 2-3 weeks after flowering increase the leaf Zn
& Cu concentration to sufficiency level & are more effective than applying through fertigation
(Kallenson et al. 2000).
– Application of Ca (2g/L), complete fertilizer (2g/L), Fe (1g/L), & Cu (1g/L) in the form of foliar sprays
improves fruit quality & produces lowest percentage of small & blank nuts in Pistachio cv. Owahadi
(Hokmabadi et al. 2009).

30. Irrigation
– Pistachio is drought tolerant, but successful commercial
cultivation requires adequate soil moisture, particularly
during the summer.
– Insufficient soil moisture reduces tree growth & yields,
causes nut production to be lighter & smaller, & increases
number of blanks & non splits.
– If rains are sufficient during winters, it will provide enough
soil moisture for proper growth of pistachios during
summers.
– It rainfall is less than 40 cm during winters, 2 irrigations
during summers are recommended.
– Pistachio orchards are mostly irrigated with furrow system of irrigation. However, drip irrigation system
is also practiced.

31. Pistachio nuts are physiologically mature
when the hull separates easily from the shell.
Maturity indices of Pistachio

32. Harvesting
– Pistachio trees begin bearing the fourth or fifth year after budding.
– However, a significant crop is not harvested until the seventh or eighth season, with the first
full production year occurring around year 12.
– Most harvesting in established pistachio orchards is done mechanically. Pistachio trees are
shaken like pecan trees to harvest pistachio nuts.
– Harvesting before or after that critical point, results in undeveloped kernels or in stained shells,
respectively.
– There are 7 to 10 days when harvesting can be done, without shell-staining occurring.
– Shell staining increases the longer the nuts stay on the tree.
– However, stained shells usually result when the hull is not removed the same day of harvest.
– Staining occurs from tannins in the hull.

33. Pistachio Harvesting in New Mexico

34. Fruit Quality Enhancement Techniques
– Pistachio nuts are consumed after salting & roasting in shells.
– Salting before roasting is done by soaking nuts in 15% salt for 23-30 minutes.
– After soaking, nuts are dried at 160-200 ͦF for about 10-15 minutes to remove
excess water before roasting (Kedar & Muranto 1985).
– Roasting is accomplished by heating the dried pistachio nuts in a rotating drum
of a roaster & gradually raising the temperature to 250 or roasting temperature
until the desired degree of roasting is obtained (Kedar & Muranto 1985).
– Roasting leads to physical, chemical, textural & sensor changes in products.
– It enhances flavor, colour, texture & appearance of the nuts & overall palatability.

35. Pistachio Processing

36. Storage of nuts
– After proper drying & roasting the nuts can be stored for 2 years at 32 ͦF & at
65% RH without quality deterioration (Kedar & Muranto 1985).
– Pistachios can also be stored for 14 weeks at 95 ͦF after vaccum packing
(Leufven et al. 2010).

37. Physiological disorders
– Pistachios display three physiological conditions.
– The first is alternate bearing; an annual fluctuation of large crops with poor
crops.
– The second is the production of blank, or unfilled nuts.
– The third is non-split nuts, nuts that fail to split along the lateral nut suture.
– All three phenomena appear to be ultimately related to crop load and are
therefore probably related to carbohydrate competition.
– Thus, far little is known about the specific mechanism of each, though
correlation with crop load is apparent in each case.

38. Pistachio inflorescence bud abscission dynamics as a
function of embryo weight, crop load and vegetative growth
– Mahvelati et al. (2018) reported that Inflorescence bud abscission, the visible mechanism of alternate
bearing in Pistacia spp. is a within-branch phenomenon precipitated by the developing embryos in
the growing fruits on 1 year-old shoots.
– The pattern of inflorescence bud drop strongly suggests an inability to support nut production on a
single shoot in successive years.
– The function of inflorescence bud drop is to allow the individual branch to recover carbohydrate
status the following season, and produce again in two years.
– It is the synchrony among the apically dominant branches that produces the alternate bearing within
a tree, the orchards and regions.
*Source: Acta Hortic. 1229. ISHS 2018. DOI 10.17660/ActaHortic.2018.1229.52

39. Major Diseases
& their
Management

40. Verticillium Wilt
Causal organism Type of damage Control
Verticillium dahliae  The fungus has
broad host range, is
widespread & can
survive in soil for
years.
 Roots are infected
& fungus eventually
plugs the water
conducting tissues,
causing wilting &
tree death.
 Use resistant rootstock (P.
integerrima).
 Soil fumigation &
fungicidal drenching are
expensive but can
eliminate the fungus.

41. Phytopthora root rot
– Fungus (Phytopthora spp.) attacks roots & trunks of pistachio trees in poorly
drained soils.
– Avoiding heavy poor drained soils is the primary mean of control.
– Proper tree care, to ensure vigour & good overall health will increase the
natural resistance of the tree.
– Fungus (Botrytis cineria) enters the flower cluster, goes down into the stem &
girdle them.
– Fungus growth is favoured by rain and cool temperature at bloom.
– Application of fungicide especially benomyl reduced the number of blighted
shoots.
Botrytis shoot blight

42. Aflatoxin
– Contamination of pistachio nuts with aflatoxin is one of the major problem that
threats its export & food safety in Iran.
– Early splitting of hulls can allows, cause development of aflatoxin on the kernel
(Doster & Michaillides 1995).
– This contamination can be minimized by rapid dehydration of the nuts & by
avoiding delays between harvest & dehydration.
– Rapid cooling & storage temperature (<41 ͦF) can be employed if delays are
unavoidable (Ahmadi & Tajabadipour, 2011).

43. Botryspaheria fruit, panicle & shoot blight
– Fungus (Botryspaheria dothdea) attack flowers, young shoots, buds,
leaves and fruits in years with rainfall during bloom.
– It is worse when high temperature accompanies rains or if overhead
irrigation keeps the tree moist, when it is warm.
– Control is achieved by avoiding irrigation and through sanitation of
organs affected in previous, where the fungus overwinters.

44. Major
Insect - pests & their
Management

45. Insect name Causal organism Type of damage Control
Sting bug or plant
bugs
Leptoglossus spp.,
Thyanta spp., &
Lygus spp.
 Brown to black spotting of
shells is sometimes
accompanied by kernels
necrosis.
 Early season feeding
usually results in fruit
drop, but late season
feeding cause staining of
nuts.
In Iran & Syria, nuts with stained
shells & kernels are soaked post
harvest & dyed red to disguise
the lesions.
Citrus fly mite Brevipalpus lewiisi  It overwinters under the
bark & bud scales & then
feed on fruits in early
spring, causing a blotchy
discolouration.
 High population may
render entire fruit cluster
unmarketable.
A dormant oil spray possibly
combined with an insecticide in
late winter can kill some of the
overwintering adults & reduce
pest population.

46. Insect name Causal organism Type of damage Control
Navel orange worm Amyelosis
transitella.
 The larvae of the moth
enter the nuts through
cracks in the hull & then
bore into & eat the kernels.
 The pest overwinters in the
damaged nuts (mummies)
either on the tree or on the
ground.
 Removal of mummified
fruits & early harvesting.
 Spray carbaryl during
early stages of hull
splitting.
Pistachio seed eater Megastigmus
pistachio
It is most serious pest as it
feeds on the kernels &
reduces yield by about 10-
20%.
-
Gypsy moth Lymantria dispar It attacks pistachio & other
nut plantations.
Spray Virin ENS at
0.1litre/ha.

47. Thank You