The plant is a fast-growing, trailing or climbing vine with thin stems and tendrils. Male and female flowers are borne separately on the same plant, and require insects for pollination. Flowers are borne singly in the leaf axils. Male flowers appear first and usually exceed the number of female flowers by about 25 to 1. The flower opens at sunrise and remain open for only 1 day. The fruits are characterized by a pebbly surface of smooth warts and smooth lengthwise ridges. Immature fruits are light green, oblong, pointed at the blossom end and have white flesh. As the fruits begins to mature, the surface gradually turns yellow or orange. At maturity, it tends to split open, revealing orange flesh and bright red placenta which the seeds are attached. Seeds are tan and oval, with a rough etched surface; there are about 150 to 200 seeds per ounce (5 to 7 seeds per gram). The probable place of origin of bitter melon is either China or India
Other names. Bitter gourd (U.S.A.), balsam pear (U.S.A.), fukwa (China), kerala (India), nigai uri (Japan) and ampalaya (Philippines).
Market Information
Marketing. In 1988 at the San Francisco wholesale market bittermelon supplies came primarily from Mexico from December through March. Prices ranged from 65¢ to $1.50 per pound with December having the highest prices. From April to mid May supplies came from the Dominican Republic and was typically $1.00 per pound. California supplied the market from mid May through November. August through October saw the lowest prices, 20 to 30¢ per pound. In November it rose to 40 to 65¢ per pound. In June it was $1.00 to $1.50 per pound.
A worksheet showing sample costs to produce bitter melon is included at the end of this leaflet. The sample costs are for a small farm in Fresno county in 1990. The total cost of production came to almost $7,200 per acre, or $4.79 per 20 pound box, assuming 1,500 boxes per acre.
Current production and yield. It is widely grown in China and India and throughout Southeast Asia, but is also grown in small acreages in the United States, primarily in California and Florida. A good yield is 10 to 12 fruits per plant, or 5 to 7 tons per acre (11.2 to 15.7 metric tones per hectare).
Use and nutrition. In this country, bitter melon is grown entirely for its immature fruits, which are used in oriental cooking; however, in some countries, the young leaves are also harvested and used as potherb. The immature fruits are a good source of vitamin C and provide some vitamin A, phosphorus, and iron. The tender vine tips are an excellent source of vitamin A, and a fair source of protein, thiamin, and vitamin C. The bitter flavor in both the fruits and leaves is due to the alkaloid morodicine, which can be reduced somewhat by parboiling or soaking in salt water. Immature fruits are least bitter; ripe fruits are extremely bitter and are reported to be toxic to man and animals. The literature on bitter melons abound with accounts of a wide range of medicinal uses of various plant parts or their extracts.
Culture
Climatic requirements. Like other cucubits, bitter melon is a crop that grows well in the warm temperature that are preferred by squash or muskmelons. Frost can kill the plants and cool temperatures will retard development. Bitter melon is normally grown as an annual crop, but can perform as a perennial in areas with mild winters.
Propagation and care. Plantings of bitter melon are commonly established by direct-seeding in the field. Seeds should be planted about 1/2 inch (1.2 cm) deep. When planted in warm soil, seedlings will emerge in a week or less. Plantings can also be established with transplants, but plants should be grown by a method that avoids disturbance of the root system during planting. Bare-root plants will not survive well. From seed, the first male flowers appear in 5 to 6 weeks and the first fruiting flowers about 10 days later.
Bitter melon culture requires a trellis to support the climbing vine, so that the fruit will not contact the soil surface. The trellis should be about 6 feet (1.8 m) high, constructed from stakes 4 to 6 feet (1.2 to 1.8 m) apart, with a system of vertical strings between top and bottom horizontal wires, similar to that used for pole beans. Rows should be spaced 48 to 60 inches (114 to 152 cm) apart, with plants 18 to 24 inches (45 to 60 cm) apart in the row. Plant destiny will range from 5,500 to 7,000 plants per acre (13,585 to 17,290 plants per hectare) depending upon spacing. Bitter melon plants are also ideally suited for culture along fence lines of 6- to 8-inch (15- to 20-cm) wire mesh.
Any good agricultural soil will produce good crops of bitter melon with proper management practices. A deep, well-drained sandy loam or silt loam is ideal. Light sandy soils will warm up sooner for early crops, but are more susceptible to nutrient losses by leaching. Heavy clay soils retain more moisture, but are cooler and don't drain as well as lighter soils. Successful irrigation practices for squash, cucumbers, or muskmelons will be successful for bitter melon also. The objective should be to maintain good soil moisture in the upper 18 inches (46 cm) of soil where the majority of roots will be located. Trickle or drip irrigation is an efficient method of supplying water and nutrients to bitter melon plantings on farms where the necessary equipment is available.
The nutritional requirements of bitter melon have not been studied, but plants should respond to practices that are successful with other cucurbit crops. Most California soils will require only nitrogen and phosphorous. A total of 150 pounds (68 kg) of nitrogen and 50 pounds (23 kg) of phosphorous (as P) per acre should be adequate. The need for other elements should be determined by soil analysis. Fifty pounds (23 kg) of nitrogen and all of the phosphorous should be applied prior to planting, either by broadcasting and tilling in, or in a band a few inches deep and to the side of the plant row. The balance of the nitrogen can be applied in two or more side-dressings with furrow irrigation, or in weekly increments by trickle irrigation.
Pests. Bitter melon is susceptible to many of the diseases and insect pests that affect squash, cucumbers, and muskmelons. It is a host of watermelon mosaic virus and is probably susceptible to other cucurbit viruses. It is susceptible to powdery mildew, but this can be controlled by sulfur dust. The fruits are subject to attack by various fruit flies and fruit rots.
Harvest and postharvest practices. Young fruits should be harvested 8 to 10 days after flower opening while they are still firm and light green. The fruits will be 4 to 6 inches (10 to 15 cm) in length, 1.5 to 2.5 inches (3.8 to 6.4 cm) in diameter (depending on variety) and will weigh 3 to 4 ounces (85 to 113 g). Beyond this stage, fruits become spongy, more bitter, and lose their market value. The development of mature fruits on the plants may reduce setting of new fruits, so harvesting should be frequent enough to remove fruits at the proper market stage. If seeds are to saved for subsequent crops, some fruits can be allowed to become fully mature following the market harvest.
USDA storage recommendations are 53° to 55°F (12° to 13°C) at 85 to 90 percent relative humidity, with an approximate storage life of 2 to 3 weeks. The fruits should be handled and packaged with care to avoid abrasions. They should be isolated in storage from fruits that produce large amounts of ethylene to avoid postharvest ripening.
Sources
Seed:
W. Atlee Burpee & Co., 300 Park Avenue, Warmister,
PA 18974
Seeds Blum, Idaho City Stage, Boise, ID 83706
Sunrise Enterprises, P.O. Box 10058, Elmwood,
Conn. 06110-0058
Tsang and Ma, P.O. Box 5644, Redwood City, CA
94063
Adlerz, W.C. 1972. "Momordica charantia as a source of watermelon mosaic virus I for cucurbit crops in Palm Beach County, Florida." Pl. Dis. Rep. 56(7): 563-564.
Agrawal, J.S., A.N. Khanna, and S.P. Singh. 1957. "Studies of floral biology and breeding of Momordica charantia ." J. Indian Hort. 14(1): 42-46.
Dhary, A.J. 1971. "Midget Kerala, the pride of Sorath." Am. Hort. Mag. 50(1): 46
Federal-State Market News Service. San Francisco Fresh Fruit and Vegetable Wholesale Market Prices 1988. USDA and CDFA, San Francisco.
Kays, S.J., and M.J. Hayes. 1978. "Induction of ripening in the fruits of Momordica charantia L. by ethylene." Trop Agric. 55: 167-172.
Miller, Carey D., Lucille Louis, and Kisaka Yanazawa. 1946. "Bitter melon." In Foods Used by Filipinos in Hawaii. Univ. of Hawaii Agr. Exp. Stn. Bul. 98.
Mote, U.N. 1976. "Phytotoxicity of modern insecticides to cucurbits." J. Maharashtra Agri. Univ. 1(1): 39-42.
Pillai, O.A.A., I. Irulappan, and R. Jayapal. 1978. "Studies on the floral biology of bitter gourd (Momordica charantia L.) varieties." Madras Agric. J. 65(3): 168-171.
Rodriguez, D.B., et al. 1976. "Carotenoid pigment changes in Momordica charantia fruits." Ann. Bot. 40: 615-624.
Sadhu, M.K., and P.C. Das. 1978. "Effect of Ethral (ethephon) on the growth, flowering, and fruiting of three cucurbits." J. HortSci. 53(1): 1-4.
Sundarajan, S., and C.R. Muthukrishnan. 1981. "The high yielding Co. 1 bitter gourd. Indian Hort. April/June 1981, 25-26.
Tropical Products Transport Handbook. USDA Agric. Handbook 668. 1987.
Yamaguchi, Mas. World Vegetables. AVI Publishing Company, Inc. Westport, Conn. 1983. 415 pp.
Authors: Hunter Johnson, Jr., Extension Vegetable Specialist Emeritus, UC Riverside; Revised by Claudia Myers, UC Small Farm Center.
Figure 2. Female bitter melon flowers with developing fruit (Photo by Hunter Johnson).
Figure 3. Bitter melon at market maturity on the right. On the left is a fruit that has matured further, the skin turns yellow and the interior a bright red (Photo by Hunter Johnson)
2/28/91
Sample costs to produce bitter melons in Fresno County are based on 1,500 - 20 lbs. boxes per acre. Field labor is $5.50 per hour reflecting 7.65% social security, 3.4% unemployment insurance and 11.3% workmen's compensation. Bitter melons, in this case, are planted 5' apart between rows and 5' in the row. Bitter Melons are usually farmed from March to early November. This is one crop in a 5 acre farm where other trellised vegetables are produced.
| PRE-HARVEST COSTS |
|
|
| Land Preparation | ||
| Dicing, Furrowing, Custom |
|
|
| Preplant Fertilizer | ||
| 1.5 hrs. labor |
|
|
| Material |
|
|
| Bedding and Plastic Laying, Custom |
|
|
| Plants 1,742 @ $65/1000 |
|
|
| Planting (18 hrs. labor) |
|
|
| Hoops Installation (4 hrs. labor) |
|
|
| Tunnel Closing (8 hrs. labor) |
|
|
| Staking (1600) and Netting Installation | ||
| 80 hrs. labor |
|
|
| Netting |
|
|
| Plastic |
|
|
| Venting (40 hrs. labor) |
|
|
| Irrigation (30x's @ 1.5 labor) |
|
|
| Weeding (40 hrs. labor) |
|
|
| PG&E ($25/month x 7) |
|
|
| Fertilizer - Nitrogen |
|
|
| Rent |
|
|
| Pull Stakes, Netting and Plants | ||
| 50 hrs labor |
|
|
| Miscellaneous |
|
|
| Office Expenses (6% preharvest costs) |
|
|
| TOTAL PREHARVEST COSTS |
|
|
| HARVEST COSTS |
|
|
| Boxes |
|
|
| Labor & Harvest |
|
|
| Packing & Grading |
|
|
| Transportation |
|
|
| TOTAL HARVEST COSTS |
|
|
|
TOTAL CASH COSTS |
|
|
| DEPRECIATION |
|
|
| Stakes, Sprayers and Implements |
|
|
| TOTAL DEPRECIATION |
|
|
| INTEREST ON INVESTMENT |
|
|
| Stakes, Irrigation Equip. and other Equip. |
|
|
| TOTAL INTEREST ON INVESTMENT |
|
|
|
TOTAL COST OF PRODUCTION |
|
|
Note: These costs were arrived at through consultations with bitter melon growers farming in Fresno County. Most of these growers are Southeast Asian immigrants and farm rented land with little capital and almost no equipment. Most of the labor is supplied by the family itself except during harvest, when they may hire other refugees to pick and pack. Generally, soil preparation is done by the land owner on custom basis. These farmers will usually produce other crops such as cherry tomatoes, Chinese long beans and squash.
To interpret this cost study analysis, you must keep in mind that all labor has been computed whether it was family labor or not. These bitter melons are grown under tunnels, which represent an additional $823.00 investment when labor and supplies are factored in.
Your cost may be different depending on the degree of mechanization, efficiency and management ability to get the jobs done on time and efficiently. Should your cost vary by a large degree, consult your local farm advisor to fully understand the reasons why this is so.