About the crop
Ash gourd (Benincasa hispida) is a popular vegetable cultivated throughout
Kerala. The fruits are cultivated mainly for culinary purpose. The fruits are covered
by white, chalky wax, which deters microorganisms and helps impart an extraordinary
longevity to the gourd.
Climate & Soil
The optimal temperature for the growth of ash gourd is in the range of 24–27oC.
The plants are adapted to a wide range of rainfall conditions. It tolerates a wide
range of soil but prefers a well drained sandy loam soil that is rich in organic
matter. The optimum soil pH is 6.0–6.7, but plants tolerate alkaline soils
up to pH 8.0.
Co 1: High yielding variety released from the Tamil Nadu Agricultural
University. Large sized, round fruits with average fruit weight of 8.0 kg.
KAU local: High yielding variety released from the Kerala Agricultural
University. Fruits are oblong, and medium sized.
Indu: High yielding variety with good flesh thickness released
from the Kerala Agricultural University. Yield potential is 24.5 t/ha. Mean
fruit weight is 4.82 kg.
Apart from the regular variety, an extra small fruited type, known as Vaidyakumbalam,
is also grown for medicinal purpose. This medicinal ash gourd is morphologically
different from the common vegetable type in fruit size, rind thickness and shelf
Propagation & Planting
The recommended seed rate for ash gourd is 0.75-1.0 kg/ha.
January-March and September-December are the ideal seasons for growing ash 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 4.5 m x 2 m. Well
rotten FYM and fertilizers are mixed with topsoil in the pit.
Sow four or five seeds per pit at 1-2 cm depth. Avoid deeper sowing as it delays
germination. Irrigate with a rose can daily. A pre-sowing irrigation 3-4 days
before sowing is beneficial. The seeds germinate in about 4-5 days. Unhealthy plants
are removed after two weeks and only three plants are retained per pit. Soaking
seeds overnight in cold water is found to improve germination. To reduce the attack
of soil born fungus, soaking seeds in 0.2 % solution of bavistin for two hours is
In high range zone, seedlings can be raised in greenhouses to ensure good germination
and are later transplanted to the main-field. Sow two or three seeds in small plastic
pots/containers filled with potting mixture. Thin to a single seedling when they
have four to six true leaves. Water the seedlings thoroughly every morning.
Seedlings are ready for transplanting 15-20 days after sowing or when they are 10-15
cm tall. Transplant seedlings into the field at spacings similar to those used
for the direct seeding method.
Ash gourd is grown trailing on the ground by spreading dried twigs and coconut fronds
on the ground.
Balanced fertilization is essential for high yield and good keeping quality of the
fruits. 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.
During the initial stages of growth, irrigate the crop at 3-4 days interval, and
alternate days during flowering/fruiting. Furrow irrigation is the ideal method
of irrigating. But in water limited environment, trickle or drip irrigation
can be resorted to. During rainy season, drainage is essential for plant survival
Ash 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 bee-hives ensures good pollination
and avoids the need for hand pollination.
Spraying vines with flowering hormones increases 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 also been found
to increase femaleness.
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 ash gourd crop grown on raised beds. Use organic or
plastic mulch depending on availability. Mulch can be laid down before or after
transplanting and after sowing.
Fruit flies: Bactocera cucurbitae
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
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 any
infested fruits to prevent the build up of fruit fly population. Cover the fruits
in polythene/paper covers help to prevent flies from laying eggs inside the fruits.
It can also be effectively controlled by the use of banana fruit traps prepared.
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 %.
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 that touch the soil.
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
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 mancozeb 0.2% will be useful.
Powdery mildew: Erysiphe cichoracearum
The disease appears as small, round, whitish spots on leaves and stems, which later
enlarge and coalesce rapidly. 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 occurs resulting in yield reduction.
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. Plants
infected in the early stages remain stunted and yield gets severely reduced. White
fly (Bemisia tabaci) is the natural vector of this virus.
Control: Control the vectors by
spraying dimethoate 0.05%. Uprooting and destruction of affected plants and collateral
hosts should be done.
Ash gourds are mature when the stems connecting the fruit to the vine begin to shrivel.
Cut fruits from the vines carefully, using pruning shears or a sharp knife leaving
3-4 inches of stem attached. Snapping the stems from the vines results in many broken
or missing "handles."
The fruits can be harvested at different stages depending on the purpose for which
it will be used. Normally, green fruits are ready for harvest within 45-60 days;
matured ones coated with powdery substance are harvested between 80 and 90 days
after sowing. The fruit yield can vary depending on variety and crop management.
Average marketable yields are 20-25 t/ha. The harvested fruits can be stored for
several weeks in ambient conditions. It will keep for 2-3 months in temperatures
from 10 to 12°C and 50-75 % relative humidity. Avoid cutting and bruising the
ash gourds when handling them.