Everything you need to know about ash gourd cultivation, production and growth. Learn about:- 1. Introduction to Ash Gourd2. Composition and Uses of Ash Gourd3. Climate and Soil Required for Cultivation 4. Sowing Time 5. Manurial Requirement for Cultivation 6. Irrigation Requirement for Cultivation 7. Intercultural Operations 8. Harvesting and Yielding 9. Cultivated Varieties.
- Introduction to Ash Gourd
- Composition and Uses of Ash Gourd
- Climate and Soil Required for Cultivating Ash Gourd
- Sowing Time of Ash Gourd Seeds
- Manurial Requirement for Ash Gourd Cultivation
- Irrigation Requirement for Ash Gourd Cultivation
- Intercultural Operations of Ash Gourd
- Harvesting and Yielding of Ash Gourd
- Cultivated Varieties of Ash Gourd
1. Introduction to Ash Gourd:
Ash gourd is believed to have originated in Java and Japan. The diversity of cultivar in China suggested that this crop might be the indigenous to southern China. Simmond (1976) reported that ash gourd is indigenous to Asian tropics and distributed from Japan to India by foreign navigators and missionaries.
It is grown throughout the plains of India, Burma, and Sri Lanka up to an altitude of 1,500 m. It is mainly grown in North India, especially in Uttar Pradesh, where it is used for the preparation of candies.
Ash gourd belongs to a monotypic genus Benincasa of cucurbitaceae family with is single cultivated specie hispida synonym cerifera. The synonyms are wax gourd, white gourd, white pumpkin, hairy melon, Chinese preserving melon, and winter melon. Besides, it is also known by several other names as koosmanda (Sankrit), pazadaba (Persian), fakwa, funggwa, mokwa, doonqua, chamkwa (Chinese) tougan (Japanese), tankoy, Kundol (Filipino), and petha kaddu (Indian).
Ash gourd is normally grown is South East Asia, China and India. In India, it is grown in Punjab, Uttar Pradesh, Bihar, West Bengal, northeastern hill states, Odisha, Kerala and Tamil Nadu on commercial scale, however, it is grown sporadically throughout India.
The ash gourd vine with a tap root system is thick, furrowed (angular) and hispid with coarse hair, and tendrils are cylindrical and hairy. Its 22-25 cm long leaves are irregularly 5-7 lobed, reniform-orbicular, deeply cordate, and scabrous, lower rigidly hispid. The golden yellow solitary flowers in leaf axil are monoecious, and the calyx teethed at early stage are often narrow and serrated. The pistillate flowers born on 1.8-4.0 cm long hairy stalk are 5-15 cm in length.
The 2-4 cm long ovary is densely hairy with three curved and bilobed stigmas, while staminate bearing flowers stalks are 5-15 cm long with a flower diameter of 8-10 cm. The fruits are fleshy, succulent, and densely hairy at immature stage but thickly deposited with white easily removable waxy layer, which is triterpenol acetates and triterpenol at maturity. The flesh is white and generally spongy. Seeds are numerous, flat, smooth with narrow base, white, yellow or pale brown, seed size 1-1.5 × 5.7 cm, containing pale yellow oil.
The nutritional composition of ash gourd is similar to summer squash. The fruits of ash gourd are rich source of vitamin, especially vitamin C, dietary fibers, and minerals, especially potassium, magnesium, and calcium. The edible portion of ash gourd constitutes around 98%. Nutritional composition of fresh fruit is given in Table 6.1.
Mature fruits of ash gourd are used in making confectionery, i.e., candy, preserves, sweets and pickles and immature fruit (young) as culinary vegetable in West Bengal, Odisha, Kerala, Tamil Nadu and NEH Region of India. Generally, specific cultivars or land races are grown for vegetable preparation at immature stage and for the preparation of sweets and bari at mature fruit stage. The ash gourd enzyme may have potential as an alternative for calf rennet in cheese manufacture.
Extract of ash gourd has acid neutralizing property and recommended in Ayurveda for management of peptic ulcer. Fruit juice is used for treating a range of ailment, including insanity epilepsy. Satpute (1989) emphasized its importance in sport medicine, used for the improvement of musculature and also used for blood sugar patient.
It is also considered good for people suffering from nervousness and debility. The Chinese used this gourd for a range of medicinal purpose. In Ayurveda literature, it is mentioned that the fruits contain tonic, nutritive and medicinal properties. Genotype with high ascorbic acid is useful in cucurbits. Cucurbitacin from ash gourd had protective effect on kidney damage caused by mercuric chloride.
3. Climate and Soil Required for Cultivating Ash Gourd:
Ash gourd requires relatively stable high temperature, long days, and moderate humid climate for good growth. The most optimum temperature range for its growth is from 24° to 30°C. The development of more pistillate flowers is stimulated by low night temperature, short days, and humid climate, while male flower production is encouraged by high temperature, long days and dry climate. It is sensitive to frost, therefore, a frost free period of about 120-135 days is necessary.
High temperature and long day length are the important environmental factors that delay flowering in ash gourd but relative humidity and rainfall have little influence. Low temperature, short day length, high relative humidity, and cloudiness enhance pistillate flower production. Plants are sensitive to cold but can tolerate drought.
The crop can be grown on a variety of soils, ranging from sandy loam to clay loam rich in organic matter with good drainage. The soils with lighter texture that warm quickly in spring are generally utilized for raising early crop of ash gourd.
It can be grown in soils with a pH range from 5.0 to 7.5 but the most optimum pH range is 6-7. This can be grown in the soils that maintain temperature in the range of 15.5°-33.5°C with optimum 21.1°C. The soil moisture should be at least 10 to 15% above the permanent wilting point for its successful cultivation. Soil is prepared well by repeated ploughing.
4. Sowing Time of Ash Gourd Seeds:
In northern plains of India, the best time of sowing for summer crop is second fortnight of February, while suitable time for the sowing of rainy season crop is June-July in northwestern India and June to August in south India although in southern India, the crop can be grown round the year.
Suitable sowing time in hills of northern India is April- May. In northern plains, if irrigation facility is available sowing may be done in the month of April and crop should be raised at bower but the height of bower should not be more than 4.0- 4.5 feet otherwise the fruit may detach from the vine due to load.
The seed rate depends upon the variety, growing season, soil type, agro-climatic condition of the growing region, seed size, and sowing distance between rows and plants. The 1000 seed weight varies between 62 and 75 g. If four seeds with 60% germination per pit were sown, the seed rate would be about 2.5-3.0 kg/ha at recommended plant spacing, keeping population density of 5000- 6000 plants per hectare and leaving 10 per cent land area used in irrigation channel and path.
Highest germination was recorded if seed pelleting is done with a Rappu powder (Albizia amara) 500 g/kg of seed. Seed treatment is done with 0.25% carbendazim 2.5 g/kg of seed.
The seeds are generally sown either on raised bed or in pits.
Besides, following systems may be followed for the sowing of ash gourd:
In this method, shallow pits of 60x60x45 cm size are dug at recommended distance. Dutta (1966) recommended digging of pits at spacing of 1.5-2.5 m both ways. The pits after digging are left open for 3 weeks before sowing for partial solarization.
Then each pit is filled with a mixture of soil and 4-5 kg compost and a part of fertilizers like Urea 50-60g, SSP 100-120 g, MOP 80 g and insecticide furadon 1-1.5 g to protect the seedling roots from the attack of underground insects and red pumpkin beetle at cotyledonary leaf stage.
In this method, ridge and furrow is prepared manually or mechanically keeping 2.5 m distance between two rows with a channel width of 40-50 cm. The seeds are sown on the edges of raised beds after mixing above-mentioned quantity of compost, fertilizers, and insecticide thoroughly.
In this method, 15 to 20 cm raised mounds are generally prepared keeping 2.5 m distance both ways between two mounds. Similar mixture of soil, compost, fertilizers, and insecticide should be mixed as in shallow pit method. Seeds (3-4) are sown on each mound at proper depth.
Generally, three to four seeds are sown in each pit or per hill in trenches. Seed soaking is not advisable in ash gourd since Wang et al. (1997) observed decreased germinability and germination percentage with seed soaking, while high germination percentage was observed for unsoaked seeds. The seed should be sown 2 cm deep in a vertical orientation. Seed takes 4 to 6 days for normal germination at a temperature range of 25-30°C.
The recommended plant spacing in Punjab is 3 m line to line and 60-90 cm plant to plant. Nath et al. (1987) and Singh (1989) recommended spacing of 1.5-2.5 m between rows and 0.6-1.2 m between pits. The plant population varies between 5000-6000 plants per hectare.
5. Manurial Requirement for Ash Gourd Cultivation:
Farmyard manure of about 20-23 t/ha should be applied and mixed thoroughly in the soil during field preparation or mixed in soil of pits during their filling. Nath et al. (1987) recommended nitrogen 18-27 kg/ha, while Singh (1989) advocated nitrogen 45-60 kg/ha. Tandon (1987) recommended nitrogen 100 kg/ha for Punjab and 50 kg/ha for Karnataka (Table 6.2).
Singh (1989) recommended phosphorus 50-60 kg/ha, while Tandon (1987) recommended phosphorus 50 kg/ha for Punjab and Karnataka. The recommended dose of potash is 50 kg/ha in Punjab and 60 kg/ha in Karnataka, whereas, Singh (1989) recommended 60-80 kg/ha of potash.
Total amount of phosphorus and potash and one-third amount of nitrogen are mixed and applied as basal dressing near expected root zone at the time of furrow or pit preparations, while remaining two-third amount of nitrogen is given as top dressing in two equal splits about 20 days (start of vine growth) and 40 days (flower initiation) after seed sowing followed by hoeing and earthing up.
6. Irrigation Requirement for Ash Gourd Cultivation:
Ash gourd has extensive root system and responds well to irrigation. In rainy season crop, no irrigation is required unless there is a long break in rain, however, in summer season crop, light irrigation is given just after seeds sowing to facilitate germination, and subsequent irrigations are given at 8-10 days interval.
There should be sufficient soil moisture during flowering and fruit development. Over irrigation causes excessive vegetative growth, while water logging causes severe damage to crop. Irrigation is given in channels in ridge-sown crop and flood irrigation is given during summer to create the microclimate, which will favour the growth, flowering and fruiting. In ash gourd, initial vegetative growth, flowering, and fruit enlarging are the critical stages for irrigation. Any moisture stress at these stages will reduce the crop yield and fruit quality.
i. Hoeing and Weeding:
At initial stages of crop growth, the weeds compete with crop for nutrients, moisture, light and space and cause huge yield reduction. First hand weeding may be done about 15-20 days after sowing followed by shallow hoeing. A total of 2-3 weedings are needed in the whole crop season. Herbicides can also be used for weed control in ash gourd.
Pre-emergence application of pendimethalin or alachlor (1 kg/ha) may solve the problem of weeds up to 30-35 days after sowing. If weeds appear later in the season, may be controlled by hand weeding.
Mulches are mainly used to reduce or increase the soil temperature in summer or winter, respectively. High temperature affects the vegetative growth, flowering, pollination, and fruit set adversely, resulting low yield. Mulch also improves the quality of fruits by avoiding their direct contact with soil.
Organic mulches, which protect the root of the plant from heat, conserve soil moisture, reduce weed infestation and modify the soil and air microclimate, are successfully used in ash gourd. The plastic mulch may be used to cover the field immediately after seed sowing if the temperature is low. It will be helpful in early germination by increasing soil temperature and conserving soil moisture. It may also be used to protect the seedlings in early season from chill temperature.
8. Harvesting and Yielding of Ash Gourd:
The crop matures in about 90-140 days after seed sowing. Small, solid, green, hairy, immature fruits, which are usually harvested after 10-12 days of anthesis, are best for culinary purpose. The immature fruit should have uniform colour and size with partially developed seeds. Development of a thick layer of white wax is the index for judging the right stage for the harvesting of fruits at full maturity.
Using sharp knife harvesting is done leaving a long peduncle attached with fruit. Fruits harvested at full mature stage have a good keeping quality than the fruits harvested at immature stage, and they can be marketed to long distances since mature fruits are largely purchased by the confectioners who prepare candy, preserves, and Bari.
Green immature fruits can be stored for 10-14 days at 10-12.5°C temperature and 85-90% relative humidity. However, the mature fruits having a thick layer of wax may be stored up to 2-6 months at room temperature in a cool dry place. Ash gourd fruit is quite resistant to water loss but susceptible to chilling injury. Symptom of chilling injury includes widely distributed very small colorless sunken spots, which become larger later, followed by a darkening of external and internal tissues, watery breakdown, and increased decaying after shifting from storage to 15°C temperature.
The cut fruits of ash gourd may be kept for an hour without obvious browning at 20°C. For prolonged shelf life, the waxy surface should not be washed off unless it needs cleaning. During storage, dehydration may induce sponginess, an unpleasant acidic flavor may induce, and physical damage may occur. Other common defects during storage include small brown pits, seed development, and change in flavor towards sourness.
The green immature fruits can be packed into styrofoam ventilated trays or is wooden containers of 10 kg or more for commercial handling. Several value added products are prepared from mature fruits, and the most common preparations are preserves (sweets), candies, and Bari. Kushmanda avaleham (like Chyawanprash) an Ayurvedic preparation is also made from the fruit paste along with ghee and other ingredients.
The yield depends on several factors such as variety, growing season, soil type, and climatic conditions of growing region. In general, the average yield of open pollinated varieties of ash gourd varies from 30 to 35 t/ha, and of hybrid from 35 to 40 t/ha.
A variety moderately resistant to insect-pests and diseases was developed at Tamil Nadu Agricultural University, Coimbatore through selection from a local collection. The vine trailing up to 4.0 m is moderately vigorous with dark green leaves. Fruits are globular, green, large, oblong, 35 cm long and 22 cm in girth with an average weight of about 6.8 kg. First harvesting is done about 100 days after sowing with an average yield of 20-25 t/ha in 140-150 days of crop duration.
This variety was also developed at Tamil Nadu Agricultural University, Coimbatore. The green fleshed fruits are small long and spherical with an average weight of 3 kg. It gives an average yield of 34.4 t/ha in crop duration of about 120 days.
An improved variety developed at Indian Agricultural Research Institute, New Delhi is recommended for commercial cultivation in northern plains. The fruits, which are cylindrical with 23.5 cm length and 55 cm girth, are green at immature stage and white at full mature stage. The fruits at mature stage are covered with a dense pelt of minute hairs and a waxy bloom at mature stage. The average fruit weight is 7 kg and average number of fruit per plant is 3.1.
The fruit flesh is white, while seed are creamy white. It requires 140 days for first harvesting. With 33 and 30% more yield than hitherto popularly grown local varieties in summer and Kharif season, respectively, its average yield is 485 q/ha in Kharif and 409 q/ha in summer season. With higher TSS, vitamin C, and minerals than the local varieties, it has longer storage life (more than 6 months at ambient room temperature).
This variety was also developed at Tamil Nadu Agricultural University, Coimbatore and recommended for cultivation in Tamil Nadu state. Fruits are big and pale-green in colour.
A variety tolerant to mosaic diseases was developed at College of Horticulture, Vellanikkara through selection from an indigenous collection. Fruits are round, 24.3 cm long, and 23.78 cm in breadth with an average weight of 4.82 kg. It gives an average yield of 24.5 t/ha.
This variety was developed at College of Horticulture, Vellanikkara through selection from an indigenous collection and released by the State Seed Sub-Committee. Medium sized, fruits are oval to oblong in shape with a green colour at tender immature stage and white at full maturity.
The fruits are 45-55 cm long and length: breadth ratio 2.05 with an average weight of 6.1-8.1 kg. Flesh thickness is 5.1-6.2 cm. It gives an average yield of 28 t/ha in crop duration of 105-120 day for mature fruit production, however, harvesting at tender stage is advisable for better yield and market demand.
This has been identified as a promising variety at Indian Institute of Vegetable Research, Varanasi with a vine length of 4.5-5.0 cm. White fleshed fruits with average weight of 12-13 kg are oblong in shape, having seed arrangement linear. It gives an average yield of 35-40 t/ha.
This is also identified as promising variety at Indian Institute of Vegetable Research, Varanasi. Less seeded fruits with average weight of 10-12 kg are globular in shape. The average yield is 30-35 t/ha in crop duration of 110-120 days.
A variety tolerant to insect-pests and diseases was developed at Punjab Agricultural University, Ludhiana and released at state level. Medium sized fruits with average weight of 8-10 kg are globular in shape. Fruit colour is green at immature stage and covered with white shining coat at maturity. First picking of fruits starts 60 days after fruit setting. It yields 70-75 t/ha in a crop duration of about 145 days.