Culture
Pistachio locationPistachios should be planted in full sun. The size of the slow growing trees can be further controlled by pruning. When planting, avoid rough handling since the budded tops are easily broken away from the under stock.
Soil
The trees do best on soils that are deep, friable and well
drained but moisture retaining. It can, however, survive in
poor, stony, calcareous, highly alkaline or slightly acid,
or even saline soils. The root is deeply penetrating.
Pistachios will tolerate considerable drought but do best with deep, infrequent watering.
Fertilization
Since pistachios grow slowly, they do not require large
quantities of nitrogen fertilizer. A spring feeding of a
complete fertilizer such as 10-10-10 NPK should be adequate.
Pruning
Pruning can be important to commercial growers in order to
shape the trees for mechanical harvesting, but less so for
the home orchards.
The trees should be trained to a modified central leader
with 4 or 5 main scaffold limbs branching about 4 ft. from
the ground. After initial training,
Little pruning is needed except to remove interfering
branches. Heavy pruning reduces yield.
Propagation
The pistachio is usually propagated in California by budding
or grafting selected scions onto seedling stocks of P.
atlantics, P. terebinthus and P. integerrima. These
rootstock species are used because of their vigor and
resistance to nematodes and soil borne fungi.
Pests and diseases
A number of fungi attack the pistachio. The most serious
fungal disease in California is vertically wilt, which can
quickly kill trees of varying age.
Most pistachios are now grafted to vertically resistant P.
integerrima rootstock.
The trees are also sensitive to the oak root fungus,
Armillary melee. Insect pests include the aphid, Ana pleura
lentissimo and several species of leaf-footed bugs and stink
bugs.
The nuts are also very attractive to squirrels and some
birds, including blue jays and woodpeckers.
Harvest
The nuts are harvested when the husk or hull covering the
shell becomes fairly loose. A single shaking will bring down
the bulk of the matured nuts, which can be caught on a tarp
or canvas.
A fully mature tree may produce as much as 50 pounds of dry,
hulled nuts. The hulls should be removed soon after to
prevent staining of the shells. To enhance splitting, the
hulled nuts may then be dipped into water to moisten the
shell and spread out in the sun to dry.
One method of salting the split nuts is to boil them in a
salt solution for a few minutes, then retry and store them.
Stored in plastic bags pistachios will last for at least 4
to 6 weeks in the refrigerator. Frozen they will last for
months.
The pistachio is unique in the nut trade due to its
semi-split shell which enables the processor to roast and
salt the kernel without removing the shell, and which at the
same time serves as a convenient form of packaging.
About 90% of California pistachios are consumed as in-shell
snacks. Shelled pistachios are utilized commercially in
confectionery, ice cream, candies, sausages, bakery goods
and flavoring for puddings. They can also be added to
dressings, casseroles and other dishes.
Commercial potential
Pistachio nuts are considered one of the prime edible nuts,
along with almonds, macadamias and cashews.
The production of pistachio nuts in California has increased
dramatically in recent years, from some 4-1/2 million pounds
in 1977 to over 80 million today. With additional promotion,
production is estimated to ultimately exceed 129 million
pounds.
Countries of origin
This Table shows only a selection of the most important
countries of origin and should not be thought of as
exhaustive.
| Europe | Turkey, Greece, Italy, South of France |
| Africa | Tunisia |
| Asia | Iran, Afghanistan, India, Syria, Iraq |
| America | USA (California), Mexico |
| Australia |
Packaging
Pistachio nuts are packaged in, among other things, wooden
boxes cartons, playbacks (25-60 kg) and in jute bags (60
kg).
Airtight packaging is ideal because pistachio kernels
readily absorb moisture from the air, so becoming limp and
beau.
