Plant characteristics: Bitter gourd is an important cucurbit vegetable of Kerala. It is a climbing vine belonging to the family Cucurbitaceae. A well drained loamy soil with pH of 6.5-7.0 is best suited for this crop. Optimum temperature range is 25-30 0C. The charecteristic bitter taste of the fruit is due to the presence of 'momordicine'.
Varieties: Priya, Preethi, Priyanka and Arka Harit are high yielding varieties. Priyanka is recommended for acid alluvial soils of Kerala.
- January-March and September-December are the ideal seasons.
- For the rainfed crop, sowing can be started after the receipt of first few showers during May-June.
Seed rate: 5.0-6.0 kg/ha
Spacing: 2.0 m x 2.0 m
Sowing: Pits of 60 cm diameter and 30-45 cm depth are taken. Well rotten FYM and fertilizers are mixed with topsoil in the pit and seeds are sown @ 4-5 per pit. Unhealthy plants are removed after two weeks and only 3 plants are retained per pit.
Erect pandals when the plants start vining.Pandals have to be erected at a height of 6-8 feet using bamboo stakes and G.I. wire.
Water management: During the initial stages of growth, irrigate at 3-4 days interval, and alternate days during flowering/fruiting. Irrigation at 15 mm CPE (approximately at 3 days interval for sandy loam soils) is more economical than irrigating once in two days especially during summer months for water economy.
Nutrient management: Apply FYM @ 20-25 t/ha as basal dose along with half dose of N (35 kg) and full doses of P2O5 (25 kg) and K2O (25 kg). The remaining dose of N (35 kg) can be applied in several split doses at fortnightly intervals.
Weed management: Conduct weeding and raking of the soil at the time of fertilizer application. Earthing up is done during rainy season.
Fruit fly (Dacus cucurbitae):
- Apply carbaryl 10% DP in pit before sowing of seeds to destroy the pupae. In homestead gardens the fruits may be covered with polythene, cloth or paper bags to ensure mechanical protection. In large gardens apply carbaryl 0.2% or malathion 0.2% suspension containing sugar or jaggery at 10 g/l at fortnightly intervals at flowering and fruit initiation. Spray as coarse droplets on the ventral surface of leaves. Remove and destroy affected and decayed fruits.
- It can also be effectively controlled by the use of banana fruit traps coupled with the removal and destruction of infested fruits. It is more efficient than two sprayings with insecticides. The trap is prepared by applying carbofuran granules at the cut ends of ripe banana fruits (variety Palayankodan). Traps are to be set at a distance of 2 m after a border row and they may be replenished after 7 to 9 days. Start bait trapping just before flowering.
- Remove and destroy egg masses, grubs and adults occurring on leaves. Spray carbaryl 0.2%.
Red pumpkin beetle:
- Adult beetle eats the leaves, makes hole on foliage and causes damage on roots and leaves. Incorporate carbaryl 10% DP in pits before sowing the seeds to destroy grubs and pupae.
- Apply 1.5% fish oil soap. First dissolve soap in hot water and then make up the volume. Alternatively apply dimethoate 0.05%, phosphamidon 0.05% or monocrotophos 0.05%.
- It is severe during rainy season. This can be checked by spraying mancozeb 0.2% (waiting period of mancozeb is three days).
- Can be controlled by spraying nitrophenol 0.05%.
- 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.
The harvest starts from 60-65 days after sowing. Mature fruits are harvested once in a week.