| |
The
Clove of commerce is the aromatic, fully grown but
unopened dried flower buds of Syzygium aromaticum
(also known as Eugenia caryophyllus). It Is one
of the ancient valuable spices of the orient, holding
a unique position in the international trade. It
originated in Moluccas, the so called 'Spice Island'
in Indonesia. The islands of Zanzibar and Pemba
(now parts of Tanzania), Indonesia, Madagascar,
Sri Lanka and Malayasia are the important producers
of clove.
Clove was first introduced to India around 1800
AD by the East India company in its 'spice garden'
in Courtallam, Tamil Nadu. Induced by the success
of its introduction, cultivation of clove was extended
during the period after 1850 AD to Nilgiris (Burliar),
southern region of the erstwhile Travancore State
and the slopes of Western Ghats. The important clove
growing districts in India now are Nilgiris, Tirunelveli,
Kanyakumari, Nagercoil and Ramanathapuram districts
of Tamil Nadu; Kozhikode, Kottayam, Kollam and Thiruvananthapuram
Districts of Kerala and South Kanara district of
Karnataka. As per the estimates for 1988-89, the
total area of 1855 hectares under clove cultivation
in India spreads over 951 hectares in Kerala, 660
hectares in Tamil Nadu, 181 hectares in Karnataka
and 63 hectares in Andaman and Nicobar islands.
|
 |
| Clove
is a tropical plant and requires warm humid climate.
Although there is a general belief that clove requires
proximity to sea for the proper growth and yield,
experience in India has shown that the trees do
well in the hinterland conditions too. Clove thrives
in all situations ranging from seal level upto an
altitude of 1000 meters. Deep loam soil with high
humus content found in the forest region is best
suited for its cultivation. It grows satisfactorily
on laterite soil, loam and rich black soil having
good drainage. |
| Clove
plantations in India are reported to have originated
from a few seedlings obtained originally from Mauritius.
The germplasm collections made from within the country
have not therefore given appreciable variability
in yield and growth factors. Clove is propagated
through seed obtained from ripened fruit, known,
popularly as 'mother of clove'. Fruits are taken,
from trees more than 15 years of age and of
regular yielding nature. They are allowed to ripe
on the trees and to drop down naturally. Such
fruits are picked up from the ground and sown
directly in the nursery. Otherwise fruits are
soaked in water overnight and the seeds obtained
after removal of the pericarp are sown. The pericarp
is removed by rubbing the fruits with sand or
ash. Seeds are good for better and early germination.
About 250-300 fruits weigh one kilogram while
450-500 seeds are required to get the same weight.
As seeds lose viability within one week after
harvest under normal conditions early sowing is
practiced. Only fully developed and uniform sized
seeds which show signs of germination by the presence
of pink radicle are ideal for sowing. Heaping
the fruits for one or two days or keeping them
in airtight bags leads to the death of seeds. |
| Raised
nursery beds are prepared on fertile soil with high
percentage of organic matter. The beds normally
measure one metre width and two to three metre length.
Seeds should be placed flat at a depth of about
2.5 cm with a spacing of 12 to 15 cm. Care should
be taken to prevent leaching of the beds in rain.
Germination commences in about 10 to 15 days and
completes by about 45 days. The slender and delicate
seedlings grow very slowly. Judicious watering is
necessary throughout the nursery period to maintain
optimum moisture in the soil. Seedlings can be retained
in the nursery till they attain a height of 25-30
cm in six months and then grown in pots for another
12-18 months. For potting, seedlings are transferred
to bamboo baskets or mud pots or Polythene bags
filled with potting Mixture. Seedlings are nurtured
under shade. As the root system of clove plant is
delicate, potting should be done with utmost care,
preferably on a rainy day. Clove can also be propagated
vegetatively by grafting on its own root stock.
But this type of Propagation is not popular at all. |
| The
site for cultivation of clove should have good drainage
since the crop cannot withstand water logging. It
can be grown in coconut gardens of midland. At higher
elevations it can be mix cropped with pepper or
coffee. Clove requires a location protected from
wind. If the site is open, wind breaks must be provided.
Eastern and North Eastern hill slopes, well-drained
valleys and riverbanks are ideal for clove cultivation.
The crop thrives well under open condition at high
altitude where there is fair distribution of rainfall.
The area selected for raising clove plantation
is cleared off wild growth before monsoon. Pits
of size 75 cm cube are dug at a spacing of seven
metres accommodating about 200 trees per ha. If
grown as an inter-crop, spacing is to be adjusted
based on the main crop. Pits are filled with a
mixture of compost or cattle manure and loose
friable top soil. Seedlings are planted in the
centre of the pits in May-June with the onset
of monsoon and watered regularly. Banana may be
planted to provide cool and humid atmosphere to
the tender plants. Watering may be done during
summer months. |
| Clove
trees are to be manured regularly for proper growth
and flowering. About 15 kg of rotten cattle manure
or compost is applied per plant in the initial years.
The quantity is increased gradually so that a well
grown tree of 15 years and more gets 40 to 50 kg
of organic manure. Inorganic fertilisers are applied,
starting with 20 g Nitrogen (N), 18 g Phosphorus
(P205) and 50 g Potash (K20) per plant in the first
year, 40 g Nitrogen (N), 36 g Phosphorus (P205)
and 100 g Potash (K20) per plant in the second year
and gradually incrased to 300 g Nitrogen (N), 250
g Phosphorus (P205) and 750 g Potash (K20) per plant
for trees of 15 years and more. Organic manure
is applied in May-June with the commencement of
monsoon. Fertilisers are given in two equal split
doses, one in May-June along with the organic
manure and the other in September-October. For
manuring shallow trench is dug around the tree
about 50 to 160 cm away from the base depending
upon the age.
No intercultivation is usually done for clove.
However, weeds are removed at regular intervals.
As the branches of full grown trees have tendency
to overcrowd, thinning is done occasionally. Dead
and diseased shoots should be removed once or
twice a year. |
| Pests |
| There
are only a few pests attacking clove. Among them
stem borer, scales and mealy bugs are important. |
| Stem
Borer (Sahyadrassus malabaricus):This is
the most important pest of clove. The caterpillars
bore into the main stem resulting in immediate drying
up of the plant above the point of attack and causing
the death of the plant ultimately. Regular inspection
of the plants and pouring a solution of 0.1% Quinalphos
into the bore hole and plugging the opening as soon
as the attack is noticed, will check the damage.
Clean cultivation and swabbing the surface of the
stem with Carbaryl 50% wettable powder as prophylactic
measure will control the pest. |
| Scales
(Lecanium psidii) and Mealy Bugs (Planococcus sp.
Psuedococus sp.): Damages due to mealy
bugs occur by sucking the sap from tender shoots.
Affected portions dry up gradually. Infestation
of scales is on leaves and tender shoots, and is
serious in the nursery. Young seedlings if attacked
are killed soon. Spraying with 0.05% Monocrotophs
or Dimethoate will control these pests. |
| Diseases,
are more damaging to clove than pests. The, important
diseases are seedling wilt, leaf rot, leaf spot,
twig blight, die back and sudden death. |
| Seedling
Wilt: Seedling wilt is found mainly in
nurseries and causes five to 40% death of seedlings.
Leaves of affected seedlings loose natural lustre,
tend to droop and ultimately die. The root system
and collar region of the seedling show varying degrees
of, discolouration and decay. Fungus such as Cylindrocladium
sp., Fusarium sp., Colletotrichum sp., Rhizoctonia
sp., and Trichoderma sp. have been isolated from
infected parts. However, the actual causal agent
is yet to be determined. Since the infected seedlings
promote spread of the disease they are to be removed
and destroyed and the nursery is drenched with any
of the copper fungicides. |
| Leaf
rot: It is caused by the fungus Cylindrocladium
quinquiseptatum. It is noticed in the nurseries
as well as in the main field both at young and mature
stages. Infection starts as dark spots at the leaf
margin and spreads sometimes with no definite pattern.
Rotting may be in the whole leaf or at the tip resulting
in defoliation, Seedling and young plants can be
sprayed with systemic fungicides like Bavistin @
2 g/litre of water for controlling the disease.
|
| Last
Spot, Twig Blight and Flower Bud shedding:
The above diseases are caused by Colletotrichum
gleosporioides. Necrotic spots of variable size
and shapes are noticed on the leaves. Severely affected
leaves wither, droop down and dry up. In nursery
seedlings die back symptoms are seen. Twigs are
infected as the symptoms extend from the leaves
through petioles. The affected branches stand without
leaves or only with young leaves at tips. Flower
buds are attacked by spreading infection from the
twigs. Shedding of flower buds occurs during periods
of heavy and continuous rainfall. Spraying 1% Bordeaux
Mixture at one to 1½ months interval reduces
disease intensity, defoliation and flower bud shedding.
Initial spray is given just prior to flower bud
formation and continued till the harvest of buds.
|
| Die
Back: This disease effects young seedlings
and grown up trees alike. The leaves rot and fall
leading occasionally to total defoliation. The twigs
also rot starting from tips and proceed downwards
resulting in drying up of branches. Spraying with
1% Bordeaux mixture is effective in controlling
the disease. |
| Sudden
Death: It is a common disease in Zanzibar
and Pemba The disease is reported to be caused by
a fungus, Valsa eugeniae. The characteristic form
of the disease occurs on apparently healthy mature
trees. The first symptom is very slight chlorosis.
It may persist for several weeks and is followed
quite suddenly by a very rapid leaf fall accompanied
by a wilt. A considerable proportion of the leaves
dry up on the tree, without abscising and becomes
bright russet-red within a few days. The cambium
around the collar of the tree is stained bright
yellow, which later spreads up the trunk and after
some months the yellow stain becomes widespread
throughout the tree. Sudden death is, closely related
with water stress and wilting can be arrested by
irrigation. |
| Clove
tree begins to yield from the seventh year of planting
and full bearing stage is attained after 15 to 20
years. The flowering season is September to October
in the plains and December to February at high altitudes.
Flower buds are formed on young flush. It takes
about five to six months for the buds to become
ready for harvest. The optimum stage for picking
clove buds is when the buds are fully developed
and the base of the calyx has turned from green
to pink colour. Such clove buds are carefully
picked by hand. Care should be taken to collect
the buds at the correct stage as otherwise the
quality of the produce will be poor to a considerable
extent. When the trees are tall and the branches
are beyond the reach, platform ladders are used
for harvesting. Bending the branches or knocking
down the bud clusters with sticks is not desirable
as these practices will affect the future bearing.
The buds after separation from the stalks are
spread evenly to dry, in-the sun on mats or cement
floors. During nights buds should be stored undercover,
lest they re-absorb moisture. The period of drying
depends on the prevailing climatic conditions.
Normally, it is possible to dry cloves in four
or five days under direct sun and in about four
hours when they are heated on zinc trays over
a regulated fire. Fully dried buds develop the
characteristic dark brown colour and are crisp.
Improperly dried and stored cloves have much darker
colour and some wheat wrinkled appearance. Such
a produce is considered inferior in quality. About
8000 to 10,000 good quality clove buds would weigh
one kilogram. |
| A well
maintained full grown tree under favourable conditions
may give four to eight kg dried buds. The average annual
yield at the 15th year may be taken as two kg per
tree or 400 kg per hectare. |
