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GINGER
(Zingiber officinale)
Ginger
is a biennial or perennial reed-like herb, grown for the
pungent, spicy underground stems or rhizomes. The stems
reach a height of 3 feet, with lanceolate, smooth leaves
up to 8 inches long. The plants are propagated by small
divisions of the rhizomes.Ginger is a tropical plant adapted
for cultivation even in regions of subtropical climate
such as the high ranges. It prefers a rich soil with high
humus content. Being an exhausting crop, ginger is not
cultivated continuously in the same field but shifting
cultivation is practised. The crop cannot withstand waterlogging
and hence soils with good drainage are preferred for its
cultivation. It is shade tolerant / loving crop with shallow
roots and therefore suitable for intercropping and as
a component in the homesteads where low to medium shade
is available.
Planting material
Ginger
rhizomes are used for planting. For selection and preservation
of seeds, adopt the following methods:
Mark
healthy and disease free plants in the field when the
crop is 6-8 months old and still green. Select best
rhizomes free from pest and disease from the marked
plants. Handle seed rhizomes carefully to avoid damage
to buds. Soak the selected rhizomes for 30 minutes in
a solution of mancozeb and malathion to give terminal
concentration of 0.3% for the former and 0.1% for the
latter. Dry the treated rhizomes in shade by spreading
on the floor. Store the treated rhizomes in pits dug
under shade, the floor of which is lined with sand or
saw dust. It is advisable to spread layers of leaves
of Glycosmis pentaphylla (panal). Cover the pits with
coconut fronds.
Examine
the stored rhizomes at monthly intervals and remove
the rhizomes that show signs of rotting. This will help
to keep the inoculum level low. Provide one or two holes
for better aeration. Treat the seed rhizomes similarly
before planting also.
Dry
ginger: Maran, Wayanad, Manantoddy, Himachal, Valluvanad,
Kuruppampady, IISR-Varada, IISR-Rejatha and IISR-Mahima
Green
ginger: Rio-De-Janeiro, China, Wayanad Local and Tafengiya
Rio-De-Janeiro
is preferable for extraction of oleoresin
Preparation
of land
Clear the field during February-March and burn the weeds,
stubbles, roots etc. in situ. Prepare the land by ploughing
or digging. Prepare beds of convenient length (across
the slope where the land is undulating), 1 m wide, 25
cm high with 40 cm spacing between the beds. Provide drainage
channels, one for every 25 beds on flat lands.
Season and method of planting
The best time for planting ginger is during the first
fortnight of April, after receipt of pre-monsoon showers.
For irrigated ginger, the best-suited time for planting
is middle of February (for vegetable ginger).
Plant
rhizome bits of 15 g weight in small pits at a spacing
of 20 x 20 cm to 25 x 25 cm and at a depth of 4-5 cm
with at least one viable healthy bud facing upwards.
Adopt a seed rate of 1500 kg/ha.
Mulching
Immediately after planting, mulch the beds thickly with
green leaves @ 15 t/ha. Repeat mulching with green leaves
twice @ 7.5 t/ha first 44-60 days and second 90-120
days after planting. Grow green manure crops like daincha
and sunn hemp in the interspaces of beds, along with
ginger and harvest the green manure crop during second
mulching of ginger beds.
Manuring
Apply
manures and fertilizers at the following rates.
| FYM |
30
t/ha |
| N:P2O5:K2O |
75:50:50:
kg/ha/year |
Full
dose of P2O5 and 50% of K2O may be applied as basal.
Half the quantity of N may be applied 60 days after
planting. The remaining quantity of N and K2O may be
applied 120 days after planting.
Aftercultivation
Remove weeds by hand-weeding before each mulching. Repeat
weeding according to weed growth during the fifth and
sixth month after planting. Earth up the crop during the
first mulching and avoid water stagnation.
Plant
protection
1. For control of shoot borer spray dimethoate or quinalphos
at 0.05%
2. For control of rhizome rot adopt the following measures:
a. Select sites having proper drainage.
b. Select seed rhizomes from disease free areas.
c. Treat seed rhizomes with 0.3% mancozeb.
d. When incidence of rhizome rot is noted in the field,
dig out the affected plants and drench the beds with cheshunt
compound or 1% Bordeaux mixture or 0.3% mancozeb.
e. Inoculation with native arbuscular mycorrhiza, Trichoderma
and Pseudomonas fluorescens at the time of planting is
recommended as a biocontrol measure.
3. For controlling the leaf spot disease, 1% Bordeaux
mixture, 0.3% mancozeb or 0.2% thiram may be sprayed.
4. For control of nematode in endemic area, apply neem
cake @ 1 t/ha at planting and carbofuran 1 kg ai/ha at
45 DAP.
Harvesting
and processing
For vegetable ginger, the crop can be harvested from sixth
month onwards. For dry ginger, harvest the crop between
245-260 days. After harvest, the fibrous roots attached
to the rhizomes are trimmed off and soil is removed by
washing. Rhizomes are soaked in water overnight and then
cleaned. The skin is removed by scrapping with sharp bamboo
splits or such other materials. Never use metallic substances
since they will discolour the rhizomes. After scrapping,
the rhizomes are sun-dried for a week with frequent turnings.
They are again well rubbed by hand to remove any outer
skin. This is the unbleached ginger of commerce. The peeled
rhizomes are repeatedly immersed in lime solution (2%)
and allowed to dry in the sun for 10 days while rhizomes
receive a uniform coating of lime. This is the bleached
ginger of commerce.
Ginger
oil
Ginger oil is prepared commercially by steam distillation
of dried powdered ginger. The yield of oil varies from
1.3 to 3.0 per cent. The major use of ginger oil is
as a flavouring agent for beverages, both alcoholic
and non-alcoholic.
Ginger
oleoresin
Oleoresin from ginger is obtained conventionally by
extraction of dried powdered ginger with organic solvents
like ethyl acetate, ethanol or acetone. Commercial dried
ginger yields 3.5-10.0 per cent oleoresin. Ginger oleoresin
is a dark brown viscous liquid responsible for the flavour
and pungency of the spice.
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