Snake gourd (Trichosanthes anguina) is native to southeastern Asia and Australia but cultivated throughout the world for its curved and oddly shaped fruits that appear like snakes hanging on the supports or ground. This subtropical plant grows very fast in warm climates and produces lots of fruits for a long time. It is suitable for growing for home garden and fresh market.
Snake gourd is adapted to wide variety of soil and climatic conditions. It requires a minimum temperature of 18oC during early growth, but optimal temperatures are in the range of 24–27oC. Snake gourd 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.
It is a high yielding variety released from the Kerala Agricultural University. Fruits are long white, with average fruit length of one metre. Suitable for growing in acid alluvial soils of Kerala. Average yield is 50 t/ha.
It is a high yielding variety released from the Kerala Agricultural University with small, uniformly white coloured fruits and average fruit weight of 474 g. The crop starts yielding in about 55 days from sowing, and it has a potential yield of 57 t/ha.
Greenish fruits with white streaks running along the length. Medium sized fruits measuring 60 cm in length. Average yield is 30-40 t/ha.
Approximately 3.0-4.0 kg of seeds are required for cultivating one hectare of land.
January-March and September-December are the ideal seasons for growing snake gourd. For the rain fed 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. Soak the seeds overnight in water for better and quicker germination. Soaking seeds in 0.2 % bavistin for 6 hours and drying in shade reduce the attack of soil born fungus. A pre sowing 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 germinate in about 4-5 days. Unhealthy plants are removed after two weeks and only three plants are retained per pit.
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 filled with potting mixture. Transplant 15-20 days old seedlings into the field at 2m x 2m spacing.
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 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 and growth.
Staking and trellising
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.Pandals are to be erected when the plants start vining. Pandals of 1.5 m height are erected using bamboo poles, wooden stakes, GI pipes or other sturdy materials. 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 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.
Snake 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. Without pruning, most of the female flowers occur between the 10th and 40th nodes, or at a height of 0.5-2.0 m. Where consumers want their snake 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.
Snake gourd needs insects to carry out the pollinating process for setting fruits. Pollination can be a problem during the wet season since bees are less active during overcast conditions. To ensure good pollination, manual pollination can be resorted to, by picking up male flowers and transferring pollens to female flowers (face-to-face touching the centre part of flowers). Introducing beehives can do away with the need for hand pollination.
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 snake gourd.
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 snake gourd crops grown on raised beds. Use organic mulch depending on availability. Mulch can be given before or after transplanting and after sowing.
Fruit flies: Bactocera cucurbitae
Fruit fly is the most destructive insect pest of snake 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. Bury any 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. Breaking of soil to expose pupae, and burning the soil in pit by dried leaves are also effective. It can also be effectively controlled by the use of banana fruit traps.
Snake gourd semilooper: Anadevidia peponis
Green coloured semilooper caterpillar cuts the edge of leaf lamina, folds it and feed from with in. It is a specific pest of snake gourd.
Control: Hand pick the caterpillars and destroy them. In severe cases spray insecticides like quinalphos (0.05%).
Epilachna beetle: Epilachna spp.
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 reduces yield.
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, make 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.
Stem gallfly: Neolasioptera falcata
Damage caused by maggots by boring into distal shoots. Thickening or galls are seen on shoots or stem.
Control: Apply insecticides like quinalphos or carbaryl
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 another.
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 cubensis
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. Spray 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. 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.
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 virus.
Control: Control the vectors by spraying dimethoate 0.05% or phosphamidon 0.05%. Uprooting and destruction of affected plants and collateral hosts should be done.
Normally, it takes 15-20 days after fruit set or 90-120 days from planting for fruit to reach marketable age. At harvest, the fruits should be light green, thick and juicy, and the seeds should be soft and white. Harvest once in every 2-3 days using a pair of scissors or a sharp knife to cut the fruit stalk and 8-10 harvests are possible in a crop life. If a fruit remains too long on the vine, it will turn spongy, sour, yellow or orange, and split open.
Yield can vary depending on variety and crop management. Under average management snake gourd yields 30-40 t/ha. Fruits of snake gourd do not keep long and should be sold in the market immediately. Remove damaged and deformed fruits. Store the fruits 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. Snake gourd is chilling sensitive and damage may occur if kept below 10°C. Keep harvested fruits away from other fruits (such as banana, pineapple and apple) that release large amounts of ethylene, a ripening hormone.