requires a warm humid tropical climate with an annual
rainfall from 150-250 cm. It grows well from mean sea
level up to an altitude of 800-900 m. Deep loam soils
with high humus content and black loams of semi-forest
regions with good drainage are suited for the cultivation
of the crop.
Select partially shaded sites having adequate protection
from high winds. Avoid exposed and shady locations.
Clove is propagated through seeds obtained from fully
developed fruits known as mother of clove. Collect fully
developed fruits from regular bearing mother trees.
Dehusk the fruits immediately after collection by soaking
in water and peeling. Prepare raised nursery beds with
fertile soil rich in humus under the shade of trees.
Sow the seeds flat at a depth 2-5 cm and a spacing of
12-15 cm. Water the beds regularly. Seedlings can either
be retained in the nursery till they attain a height
of 25-30 cm when they are ready for transplanting or
potted when they are six months old and transplanted
after another 12-18 months.
Select 18 month old seedlings for planting. Prepare
pits of size 60 x 60 x 60 cm at a spacing of 6 x 6 m
about a month in advance of planting. Allow to weather.
Fill up the pits with mixture of burnt earth, compost
and topsoil. Plant the seedlings during the rainy season,
May-June or August-September. Provide shade and irrigation
during breaks in the monsoon and summer. Banana or glyricidia
may be planted to provide shade.
is generally grown as a mixed crop with coffee, coconut,
cattle manure or compost at the rate of 15 kg / tree
/ annum during May-June.
recommended fertilizer dose is N:P2O5: K2O @ 20:18:50
g/plant during the first year and N:P2O5:K2O @ 40:36:100
g/plant during the second year. Increase gradually the
N:P2O5:K2O dose to 300:250:750 g/plant/year for a well
grown tree of 15 years or more. Apply organic manures
in May-June with the commencement of southwest monsoon.
Apply fertilizers in two equal split doses in May-June
along with the organic manures and in September-October
in shallow trenches dug around the plant about 1 to
1.25 m away from the base.
Conduct weeding and intercultivation whenever necessary.
Cut and remove dead and diseased branches of full-grown
trees to prevent over crowding. Spray 1% Bordeaux mixture
to control dieback.
Infestation of shoot borer Sinoxylon sp. on tender shoots
of young plants can be prevented by prophylactic application
of carbaryl 0.15%. Prune off the laterals of old trees
showing dieback symptoms. Do not allow dried glyricidia
and other twigs to remain in the plantation, to ensure
that the beetles will not multiply on these materials
and subsequently initiate infestation in cloves.
spot, twig blight and flower bud shedding (Colletotrichum
types of symptoms are seen viz., leaf spot, twig blight
and flower bud shedding. On the leaves, necrotic spots
of variable sizes and shapes are noticed. Severely affected
leaves wither, drop and dry up. In the nursery seedlings,
dieback symptoms are seen. Extension of the symptoms
from the leaves through petioles results in the infection
of twigs. The affected branches stand without leaves
or only with young leaves at the tips. The flower buds
are attacked by spread of infection from the twigs.
Shedding of flower buds occurs during periods of heavy
and continuous rainfall.
1% Bordeaux mixture at 1-1.5 month intervals reduces
disease intensity, defoliation and flower bud shedding.
The spraying has to be commenced just prior to flower
bud formation and continued till the harvest of flower
buds for effective control. Destruction of the weed
Clerodendron from the clove garden is recommended to
reduce the disease since the pathogen survives on this
weed during adverse conditions.
other diseases of clove are:
Grey blight of clove (Pestalotia palmarum)
Leaf spot of clove (Cylindrocladium quinqueseptatum)
Leaf spot of clove (Alternaria citri)
Sooty mould of clove (Phragmocapnius sp.)
Algal leaf spot of clove (Cephaleuros sp.)
Little leaf of clove (suspected to be due to phytoplasma).
trees begin to yield from 7-8 years after planting.
The stage of harvest of flower buds determines the quality
of the final dried product. Buds are harvested when
the base of calyx has turned from green to pink in colour.
If allowed to develop beyond this stage, the buds open,
petals drop and an inferior quality spice is obtained
to drying, buds are removed from the stem by holding
the cluster in one hand and pressing it against the
palm of the other with a slight twisting movement. The
clove buds and stems are piled separately for drying.
Buds may be sorted to remove over-ripe cloves and fallen
flowers. Drying should be done immediately after the
buds are separated from the clusters. If left too long
in heaps, they ferment and the dried spice has a whitish
shriveled appearance (khoker clove).
traditional method of drying is by exposing them to
sun in mats. The green buds are spread out in a thin
layer on the drying floor and are raked from time to
time to ensure the development of a uniform colour and
to prevent mould formation. In sunny weather, drying
is completed in 4-5 days giving a bright coloured dried
spice of attractive appearance. During drying, clove
loses about two-third of its original fresh green weight.
When properly dried, it will turn bright brown and does
not bend when pressed. The dried cloves are sorted to
remove mother of cloves and khoker cloves, bagged and
stored in a dry place. The stem after separation of
buds is dried in a similar manner as the spice, without
allowing mould formation and fermentation.
The essential oil is obtained by steam distillation
of comminuted buds or whole cloves. On distillation,
about 17 per cent essential oil is obtained which is
a colourless or yellow liquid possessing odour and flavour
characteristic of the spice. Finest oil contains 85-89
per cent eugenol. Clove bud oil is used for flavouring
food and in perfumery.
Clove stem oil is obtained from dried peduncles and
stem of clove buds (5-7%) on steam distillation. The
eugenol content of the oil ranges from 90-95 per cent.
This oil possesses a coarser and woodier odour than
Clove leaves on distillation yield 2-3 per cent oil
as a dark brown liquid with a harsh woody odour. When
rectified, it turns pale yellow and smells sweeter with
a eugenol content of 80 to 85 per cent.
Clove oleoresin may be prepared by cold or hot extraction
of crushed spices using organic solvents like acetone
giving a recovery of 18-22 per cent. The oleoresin is
chiefly used in perfumery and when used for flavouring
it is dispersed on salt, flour etc.