About the crop
Bitter gourd (Momordica charantia) is one of the most popular vegetables
in Kerala. The fruits are used in a variety of culinary preparations and possess
high nutritive and medicinal value. The fruits are rich in vitamin C and folate,
and contain alkaloids likely momordicine, saponine and albuminoides, which
are medicinally important. Juice extracted by crushing bitter gourd fruits is most
commonly used for treatment of diabetes.
Climate & Soil
Bitter gourd can be cultivated from lowland to altitudes up to 1,000 m. It requires
a minimum temperature of 180C during early growth, but optimal temperatures
are in the range of 24–270C. The crop can tolerate low temperatures,
but extreme cool temperatures will retard growth. The plants are adapted to a wide
variety of rainfall conditions. Bitter gourd tolerates a wide range of soil but
prefers a well drained sandy loam soil rich in organic matter. The optimum soil
pH is 6.0–6.7, but plants tolerate alkaline soils up to pH 8.0.
Priya: High yielding variety released from the Kerala Agricultural
University. Fruits are long and green with the distal end being greenish white in
colour. Average yield is 30 t/ha.
Preethi: High yielding variety released from the Kerala Agricultural
University. Medium sized greenish white fruits. Average yield is 10-35 t/ha. Relatively
less susceptible to fruit fly attack. Suitable for growing in Thrissur, Palakkad
and Ernakulam districts.
Priyanka: High yielding variety released from the Kerala Agricultural
University. Fruits are greenish white in colour. Average yield is 29 t/ha. Resistant
to powdery mildew disease. Priyanka is recommended for acid alluvial soils of Kerala.
Arka Harit: High yielding variety released from the Indian Institute
of Horticultural Research, Bangalore. Stem is thin and with light green, deeply
lobed foliage. Fruits are spindle shaped, skin is glossy green, and without tubercles.
Duration is 100-110 days. Average yield is 12 t/ha.
The choice of variety should be according to market preference based on fruit shape
and color. Select a variety that is well adapted to the local growing conditions
and preferred by consumers.
Propagation & Planting
Approximately 5.0-6.0 kg of seeds are required for cultivating one hectare of land.
January-March and September-December are the ideal seasons for growing bitter gourd.
For the rainfed crop, sowing can be started after the receipt of first few showers
during May-June. Prepare the soil to a fine tilth by ploughing and harrowing. Pits
of 60 cm diameter and 30-45 cm depth are taken at a spacing of 2m x 2m. Well rotten
FYM and fertilizers are mixed with topsoil in the pit.
The seeds are soaked in water for 24 hours prior to planting for better and quicker
germination. Soaking seeds in a solution of bavistin @ 0.2 % for 6 hours and drying
in shade before sowing is also recommended to reduce the attack of soil born fungus.
As seedlings require ample water for quicker germination, giving a presowing irrigation
3-4 days before sowing is beneficial. Sow four or five seeds in a pit at 1-2 cm
depth. Deeper sowing delays germination. Irrigate with a rose can daily. The
seeds will germinate in about 4-5 days. Unhealthy plants are removed after two weeks
and retain only three plants per pit.
Bitter gourd grows very fast and vines elongate rapidly within two weeks after planting.
Thereafter, the plant sends out lateral stems. Staking and trellising will
increase fruit yield and size, reduce fruit rot, and make spraying and harvesting
easier. Pandals are the most common trellising system used in Kerala.
For this, pandals of 1.5 m height are erected using bamboo poles, wooden
stakes, GI pipes or other sturdy materials when the plants start vining. Steel wires/strings,
preferably coated with rust proof materials like plastic are used to connect the
stakes, and to which coir or plastic ropes are tied in a crisscross manner so that
horizontal coir/plastic ropes run across on the top forming a net. Vines are supported
by bamboo stakes, which help vines freely climb and reach the top.
Other improved methods of trellising are also available. The trellis can be arranged
either in a lean-to or tunnel structure. For the lean-to type, the stakes are joined
between two adjoining beds forming an A shape structure. Horizontal stakes
are installed at the top joining all other beds. The stakes support the climbing
vines and lateral stems. Strings are used to secure adjoining stakes. The trellis
should be 1.8-2.0 m high, constructed from stakes 1.2-1.8 m apart. For the tunnel
type, plants are grown inside an arch shape structure made of either PVC or galvanized
iron pipe. Plants are supported by bamboo stakes where vines freely climb and reach
the top, which will then grow along the structure.
Bitter gourd develops many side branches that are not productive. To improve yield,
remove lateral branches until the runner reaches the top of the trellis. Leave 4-6
laterals and cut the tip of the main runner to induce early cropping. Removal of
lateral branches in the first 10 nodes has a positive effect on total yield.
Where consumers want their bitter gourd straight rather than curved, tie a pebble
at the end of a long piece of string to the flower end to weigh down the fruit and
keep it from curling.
Balanced fertilization is essential for high yielding and good keeping quality of
the fruits. Fertilizer dosage depends on soil type, fertility level, and soil organic
matter. Apply FYM @ 20-25 t/ha as basal dose along with half dose of N (35 kg) and
full dose of P2O5 (25 kg) and K2O (25 kg/ha). The
remaining dose of N (35 kg) can be applied in two equal split doses at the time
of vining and at the time of full blooming. A fertilizer dose of 70:25:25 kg N:P2O5:K2O
/ ha in several splits is recommended in Onattukara region. The fertilizer dose
per pit would be 28:10:10 g N:P2O5:K2O.
Bitter gourds do not tolerate drought. Maintain good soil moisture in the upper
50 cm of soil where the majority of roots are located. During the initial stages
of growth, irrigate at 3-4 days interval, and alternate days during flowering/fruiting.
Furrow irrigation is the ideal method of irrigating. But in high tech agriculture,
water use efficiency can be improved by using trickle or drip irrigation. During
rainy season, drainage is essential for plant survival and growth.
In bitter gourd, male and female flowers are borne separately on the same plant,
and male flowers normally exceed the females by about 25:1. Spraying vines with
flowering hormones after they have six to eight true leaves will increase the number
of female flowers and can double the number of fruits. For example, one application
of gibberellic acid at 25-100 ppm increases female flowers by 50 % and can
work for up to 80 days. Application of ethrel (an ethylene releasing compound) has
been found to increase femaleness in bitter gourd.
Bitter gourd is a cross pollinated crop. Insects, especially bees, pollinate flowers.
Pollination can be a problem during the wet season since bees are less active
during overcast conditions. Introduction of beehives ensure good pollination
and avoid the need for hand pollination.
Conduct weeding and raking of the soil at the time of fertilizer application. Earthing
up is done during rainy season. Hand or hoe weeding can be performed as needed.
Mulching is commonly used for bitter gourd crops grown on raised beds. Use organic
or plastic mulch depending on availability. Mulch can be laid down before or after
transplanting and after sowing.
For controlling pests of bitter gourd, go for mechanical and biological control
methods. Chemical control of insect pests should be done only when significant damage
occurs. Avoid pesticides that kill or inhibit the development of beneficial
organisms especially the pollinators. Choose pesticides that last only a few days.
Fruit flies (Bactocera cucurbitae)
Fruit fly is the most destructive insect pest of bitter gourd. Fruit fly maggots
feed on the internal tissues of the fruit causing premature fruit drop and also
yellowing and rotting of the affected fruits. This fly is difficult to control because
its maggots feed inside the fruits, protected from direct contact with insecticides.
Control: Apply carbaryl 10 % DP
in pits before sowing of seeds to destroy the pupae. Breaking of soil to expose
pupae, and burning the soil in pit by dried leaves are also effective. Bury infested
fruits to prevent the build up of fruit fly population. In homestead gardens, covering
the fruits in polythene/paper covers help to prevent flies from laying eggs inside
the fruits. In large gardens apply carbaryl 0.2 % or malathion 0.15 % suspension
containing sugar or jaggery @ 10 g/litre at fortnightly intervals at flowering and
fruit initiation. It can also be effectively controlled by the use of banana fruit
Epilachna beetle (Epilachna
The yellowish coloured grubs and adults of the beetle feed voraciously on leaves
and tender plant parts, and the leaves are completely skeletonized leaving only
a network of veins. When in large number, the pest causes serious defoliation and
Control: Remove and destroy egg
masses, grubs and adults occurring on leaves. Spray carbaryl 0.2 %.
Pumpkin beetle (Aulacophora
fevicolis, A. cincta and A. intermedia)
Adult beetles eat the leaves, makes hole on foliage and causes damage on roots and
leaves. Grubs cause damage by feeding on root. It also feeds on flowers and bores
into developing fruits.
Control: Incorporate carbaryl 10%
DP in pits before sowing the seeds to destroy grubs and pupae.
Aphids (Aphis gossypi)
Aphids in large number congregate on tender parts of plant and suck sap
resulting in curling and crinkling of leaves. Ants carry aphids from one plant to
Control: Apply 1.5% fish oil soap.
First dissolve soap in hot water and then make up the volume. Alternatively apply
dimethoate 0.05 %.
Downy mildew (Pseudoperonospora
Cottony white mycelial growth is seen on the leaf surface. Chlorotic specks can
be seen on the upper surface of the leaves. It is severe during rainy season.
Control: Complete removal and destruction
of the affected leaves. Spraying 10 % solution of neem or kiriyath preparation.
If the disease incidence is severe, spraying indofil M-45 0.2%, akomin 0.3 % or
mancozeb 0.2 % will be useful.
Powdery mildew (Erysiphe cichoracearum)
The disease appears as small, round, whitish spots on leaves and stems. The spots
enlarge and coalesce rapidly and white powdery mass appears on the upper leaf surface.
Heavily infected leaves become yellow, and later become dry and brown. Extensive
premature defoliation of the older leaves resulting in yield reduction. High humidity
and heavy dew increase the severity of the disease.
Control: Control the disease by
spraying Dinocap 0.05%.
Mosaic (Cucumber Mosaic Virus)
Mosaic disease is characterized by vein clearing and chlorosis of leaves. The yellow
network of veins is very conspicuous and veins and veinlets are thickened. Growths
of plants infected in the early stages remain stunted and yield of the plant get
severely reduced. White fly (Bemisia tabaci) is the natural vector of this
Control: Control the vectors by
spraying dimethoate 0.05%. Uprooting and destruction of affected plants and collateral
hosts should be done. Harvesting can be done only after 10 days (at least) of insecticide/fungicide
application. The fruits should be washed thoroughly in water before cooking.
Bitter gourd requires close attention at harvest time and fruits must be harvested
frequently. Normally, it takes 15-20 days after fruit set or 90 days from planting
for fruit to reach marketable age, however, fruits can be harvested at earlier stages
depending on the purpose for which it will be used. Ideally, at harvest fruits should
be light green, thick and juicy, and the seeds should be soft and white. Harvest
every 2-3 days using a pair of scissors or a sharp knife to cut the fruit stalk.
If a fruit remains too long on the vine, it will turn spongy, sour, yellow or orange,
and split open.
Yield varies depending on variety and management. Average marketable yields
are 15-20 t/ha, and some hybrids yield up to 40 t/ha. The harvested fruits do not
keep long and should be sold in the market immediately. Remove damaged and
deformed fruits. Carefully arrange fruits in bamboo baskets or boxes and store in
a cool place at 12-13°C with 85-90 % relative humidity. Under this condition,
fruit storage life can be extended 2-3 weeks. Bitter gourd is chilling sensitive
and damage may occur if kept below 10°C. Do not store fruits at temperatures
above 13°C, as this will result in fruits turning yellow and splitting open.
Keep harvested fruits away from other fruits (such as banana, pineapple and apple)
that release large amounts of ethylene, a ripening hormone.