The nutmeg tree is a large evergreen tree spice belonging to Myristicaceae family
and grows to a height of about 18 m. It produces fruits eight to nine years
after planting. The fruit of nutmeg tree, which is similar in colour and size to
apricot, splits when ripe revealing the brilliant red arils encasing the brown nut.
The red arils on drying become orange in colour and are the mace of commerce. The
nut is also dried until the kernel inside rattles.
Area, production and productivity of nutmeg
Area, production and productivity of nutmeg
Area (000 ha)
IISR-Viswashree is the only known variety. Important characters are early bearing
with potential yield at 25th year. Fruits in clusters (4-5). Nut dry recovery 70%,
Mace dry recovery 35% yield from 8th year old tree-1000 fruits; 1.33 kg mace;9kg
Production of quality planting materials
Fully ripened tree-burst fruits are selected for raising seedlings. The fleshy rind
and the mace are removed before sowing. The seeds should be sown immediately after
collection. If there is any delay in sowing, the seeds should be kept in baskets
filled with damp soil. The seedbeds of 100-120 cm width, 15 cm height and of convenient
length may be prepared in cool and shady places. A mixture of garden soil and sand
in the ratio 3:1 may be used for preparing nursery beds. Over this, sand is spread
to a thickness of 2-3 cm and the seeds dibbled 2 cm below the surface at a spacing
of about 12 cm on either side. Seeds germinate within 50-80 days after sowing. When
the plumule produces two elongated opposite leaves, the seedlings are to be transferred
from beds to polybags.
Since the nutmeg trees require shade, suitable fast growing shade trees like Albizia,
Erythrina etc. are planted in advance. Banana can also be grown as a shade
crop in the early stages. Pits of 90 x 90 x 90 cm are dug at a spacing of 8 x 8
m with the onset of southwest monsoon. The pits are filled with topsoil and compost
or well-decomposed cattle manure and seedlings are planted.As nutmeg is cross-pollinated,
considerable variations are observed in the crop. The plants differ not only for
all aspects of growth and vigour, but also for sex expression, size and shape of
fruit and quantity and quality of mace. An important problem in nutmeg cultivation
is the segregation of seedlings into male and female plants resulting in about 50%
unproductive male trees. The only alternative is to adopt vegetative propagation
either by top-working male plants or using budded or grafted plants.
Due to sex problems and long prebearing period of seedlings, now-a-days grafts are
preferred for planting. For raising rootstocks, naturally split healthy fruits are
harvested during June-July. The seeds are extracted from the pericarp and sown immediately
in sand beds of convenient length, 1 to 1.5 m width and 15 cm height. Regular watering
is necessary for good germination. Germination may commence from about 30th day
and last up to 90 days after sowing. About 20 days old sprouts are transplanted
to polythene bags containing a mixture of soil, sand and cow dung (3:3:1).
The selected rootstock at the first leaf stage should have a thick stem (diameter
of 0.5 cm or more) with sufficient length so as to enable to give a cut of 3 cm
length. Scions from upright growing shoots with 2-3 leaves, collected from high
yielding trees can be used for grafting. The stock and scion should approximately
have the same diameter. A “V ” shaped cut is made in the stock and a
tapered scion is fitted carefully into the cut. Bandaging at the grafted region
may be done with polythene strips. They are then planted in polythene bags of 25
cm x 15 cm size containing potting mixture. The scion is covered with a polythene
bag and kept in a cool shaded place protected from direct sunlight. After 1 month,
the bags can be opened and those grafts showing sprouting of scions may be transplanted
into polythene bags, containing a mixture of soil, sand and cow dung (3:3:1) and
kept in shade for development. The polythene bandage covering the grafted portion
can be removed after 3 months. During grafting, precautions should be taken to prevent
wilting of scions and to complete the grafting as soon as possible. The grafts can
be planted in the field after 12 months.
Preparation of land and planting
Planting in the main field is done at the beginning of rainy season. Pits of 0.90
m x 0.90 m x 0.90 m size are dug at a spacing of 8 m x 8 m and filled with organic
manure and soil about 15 days earlier to planting. For planting plagiotropic grafts,
a spacing of 5 m x 5 m has to be adopted. A male plant has to be planted for every
20 female plants in the field.
The plants should be shaded to protect them from sun scorch during early stages.
Permanent shade trees are to be planted when the site is on hilly slopes and when
nutmeg is grown as a monocrop.
Nutmeg can best be grown as an intercrop in coconut gardens that are more than 15
years old where shade conditions are ideal. Coconut gardens along river beds and
adjoining areas are best suited for nutmeg cultivation. Irrigation is essential
during summer months.
Apply 10 kg cattle manure or compost per seedling during the first year. Increase
the quantity gradually till a well-grown tree of 15 years and above receives 50
kg of organic manures per year. Apply N:P2O5:K2O
@ 20:18:50 g/plant during the first year. This may be doubled in the next year.
Gradually increase the N:P2O5:K2O dose to 500:250:1000
g/plant/year to obtain full dose from 15th year onwards.
Black scale (Saissetia nigra)
The black scale infests tender stems and leaves especially in the nursery and sometimes-young
plants in the field. The scales are clustered together and are black, oval and dome
shaped. Black scales feed on plant sap and severe infestations cause the shoots
to wilt and dry. It can be controlled by spot spraying with quinalphos 0.025%.
White scale (Pseudaulacaspis cockerelli)
The white scale is greyish white, flat and shaped like a fish scale and occurs clustered
together on the lower surface of leaves especially in nursery seedlings. The pest
infestation results in yellow streaks and spots on affected leaves and in severe
infestations the leaves wilt and dry.
Shield scale (Protopulvinaria mangiferae)
The shield scale is creamy brown and oval and occurs on tender leaves and stems
especially in nursery seedlings. The pest infestation results in wilting of leaves
Leaf spot and shot hole (Colletotrichum gloeosporioides)
Sunken spots surrounded by a yellow halo are the initial symptoms. Subsequently
the central portion of the necrotic region drops off resulting in shot hole symptoms.
Dieback symptoms are also observed in some of the mature branches. On young seedlings
drying of the leaves and subsequent defoliation are seen. The disease can be controlled
by spraying 1% Bordeaux mixture two or three times during rainy season.
Two types of blights are noticed in nutmeg. The first one is a white thread blight
wherein fine white hyphae aggregate to form fungal threads that traverse along the
stem underneath the leaves in a fan shaped or irregular manner causing blight in
the affected portions. The disease is caused by Marasmius pulcherima. The
dried up leaves with mycelium form a major source of inoculum for the spread of
the disease.The second type of blight is called horse hair blight. Fine black silky
threads of the fungus form an irregular, loose network on the stems and leaves.
These strands cause blight of leaves and stems. However, these threads hold up the
detached, dried leaves on the tree, giving the appearance of a bird’s nest,
when viewed from a distance. This disease is caused by Marasmius equicrinus.
Both the diseases are severe under heavy shade.
These diseases can be managed by adopting phytosanitation and shade regulation.
In severely affected gardens, Bordeaux mixture 1% spraying may be undertaken in
addition to cultural practices.
Immature fruit split, fruit rot and fruit drop are serious in a majority of nutmeg
gardens in Kerala. Immature fruit splitting and shedding are noticed in some trees
without any apparent infection. In the case of fruit rot, the infection starts from
the pedicel as dark lesions and gradually spreads to the fruit, causing brown discolouration
of the rind resulting in rotting. In advanced stages, the mace also rots emitting
a foul smell. Phytophthora sp. and Diplodia natalensis have been
isolated from affected fruits. However, the reasons for fruit rot could be both
pathological and physiological.
Bordeaux mixture 1% may be sprayed when the fruits are half mature to reduce the
incidence of the disease.
Fruits are available throughout the year, but the peak period of harvest is fromJune
to July . When fruits are fully ripe, the nuts split open. These are either plucked
from the tree or allowed to drop. The two major products are nutmeg and mace. Dried
nutmeg and mace are directly used as spice and also for the preparation of their
derivatives. After de-rinding the nutmeg fruit, red feathery aril (mace) is separated
from pericarp. The mace is detached, flattened and dried under sun on mats for 3-5
days. The nuts are dried in the sun for six to eight days till they rattle in their
shell. They are stored in warm dry place prior to shelling.
and value addition
Nutmeg and mace oleoresins are prepared by extracting the ground spice with organic
solvents. Yield of oleoresin is 10-12 per cent for nutmeg and 10-13 per cent for
mace. Mace oleoresin possesses a fine, fresh fruity character.
Nutmeg contains 25-40 per cent of fixed oil that can be obtained by pressing the
crushed nuts between plates in the presence of steam or by extracting with solvents.
The product, known as nutmeg butter, is a highly aromatic, orange coloured fat with
the consistency of butter at ambient temperature.
This is obtained as pale yellow to white volatile liquid possessing a fresh warm
aromatic odour. The yield ranges from 7 to 16 %. The unshelled nuts are coarsely
crushed in a mechanical cracker and steam distilled.
The mace yields 4-17 % colourless to pale yellow liquid possessing organoleptic
properties similar to nutmeg oil. Nutmeg and mace oil are also used for flavouring.