Vigna radiata is a member of the Fabaceae (pea) family.
The 18 to 36 inch tall mung bean plants produce clusters of 2 to 8 slender, 3-4 inch long, black, slightly fuzzy pods with very small green seeds. Each pod may contain as many as 15 small oval seeds depending on cultural conditions. The mung bean is an ancient crop of Asia, where there are many seed sizes, shapes and colors. Mung been sprouts are produced domestically from green seeded cultivars. The mung beans' ancestors are annual plants with both short and long day cultivars, however, domestic cultivars are primarily temperature sensitive rather than photoperiod sensitive.
Other names. Mung bean: nong taao, pua sha (Hmong); moyashi-mame (Japanese); lu tou (Mandarin Chinese); look dou (Cantonese Chinese); balatung (Filipino); dau-xanh (Vietnamese). Mung sprouts: kolo taac (Hmong); moyashi (Japanese); yar tsai (Mandarin Chinese); ngar choy (Cantonese Chinese).
Marketing. Because the primary use of mung beans is for the production of bean sprouts, sprouting quality determines marketability. Whole seed of bright green color is a surface indicator of good sprouting potential. Harvest damage, prolonged standing in the field, and molding associated with rain damage deteriorates seed coat color and impairs sprouting quality, and may make a seed lot unusable and unsalable. Early planting and timely harvest often improve opportunities for high quality seed and sprouts. As each individual sprouter differs slightly in the equipment and technique used, the final salability of mung beans depends on matching seed qualities with the particular needs of the sprouter.
Mung Bean Production Costs (Colusa County - 1986)
by Mike Murray, Farm Advisor, Colusa County
land preparation 64.00 - 66.00
growing costs 73.00 - 92.00
harvesting, etc. 130.00
TOTAL 397.00 - 418.00
Contract Price Yield (cwt/acre - clean)
($/cwt) 15 18 20
25 $375 $450 $500
30 $450 $540 $600
35 $525 $630 $700
Current production and yield. Mung beans are currently produced in the U.S. in Oklahoma, Texas and California. Worldwide, mung beans are produced in Australia, India, Thailand and other Asian countries. Sacramento Valley Milling, Inc. in Ordbend, CA is currently a major mung bean producer in the Sacramento Valley, producing seed under contract with growers. 1986 California grower prices were about 30 cents per pound for the seed. Field tests near Williams, CA (upper Sacramento Valley) in 1986 yielded 1800 to 2200 pounds of seed per acre on plots with 60 to 80 pounds of nitrogen applied per acre. The check plot with no added nitrogen yielded about 1500 lbs/acre. Compatible strains of nitrogen-fixing bacteria may also be used to inoculate seed prior to sowing.
Use. The principle domestic use of mung bean is the production of sprouts, commonly seen in Asian cooking. Seeds are germinated in the dark at 65-75°F for 4-5 days in special germinating containers by wetting the seeds every 4 to 5 hours. Commercially about an 8 fold sprout yield of 800 pounds of sprouts for every 100 pounds of seed is expected. An ethnic use of mung bean is for dal (or dahl), a spicy paste made from the dry seed. Mung beans can also be shelled green and used like sweet peas or the tender immature pods can be cooked. Mung beans are a staple legume in many diets around the world.
Propagation and care. Mung beans, like black-eyes, are deep rooted and susceptible to many of the same diseases and insect pests. Maturity is reached in about 120 days. In the Sacramento Valley planting in May is recommended to assure harvest before quality damaging rains occur. Plant seed into moist, pre-irrigated ground 1 to 2 inches deep, on 30 inch rows, 3 to 4 plants per foot of row (seeding rate of 15 to 30 lbs per acre). Mung beans prefer few, deep penetrating irrigations, limiting vegetative growth slightly and forcing photosynthetic partitioning to move into the seed. Generally, two or three post emergence irrigations are adequate.
Harvest and postharvest practices. The pods of mung beans are thin and brittle when dry so shattering can be a problem at harvest. Harvest conditions and management often determine crop success or failure. Direct combining is the preferred harvest method to reduce seed shattering that can be a significant factor with windrowed mung beans. Direct combining requires that the plant defoliate and dry down in a timely manner. In the past, defoliants or desiccants were used to achieve this but registered chemicals have disappeared from the marketplace. If the plants are established in May they will defoliate and dry down naturally in September.
In field trials in Solano County in 1986 several fields were harvested with axial flow combines with a bean pick-up head. They report that care should be taken to adjust the cylinder speed (<500 rpm preferred, 300 rpm optimum) and screen plates to provide as clean a product as possible. Cylinder speed and screen plates appeared to be the main limiting factor; in other words, the slower the better.
If you are going to cut and windrow instead of using a combine, the plants should be cut when approximately half of the pods turn black. There will be many green pods left, but most will continue to mature and dry due to the thickness of the stems and their ability to retain moisture. After cutting they should be allowed to dry undisturbed until harvest. If cut and raked, care should be taken to handle only once since additional handling will increase shatter loss significantly. Broken, cracked or scarred seeds will not germinate properly resulting in lower sprout yields.
Pest and weed problems. Mung beans secrete a sticky sweet substance that will attract a host of insects. Lygus appears to be the most damaging to seed yield and quality. Control of lygus during and after flowering is critical. Aphids, cucumber beetles, mosquitos and several worm types are attracted, but they appear to cause little damage. Special attention should be given to controlling black nightshade, hairy nightshade, yellow nutsedge and summer annual grasses, as all will create harvest and quality problems if not controlled.
W. Atlee Burpee & Co., 300 Park Avenue, Warmister, PA 18974
Sacramento Valley Milling, P.O. Box 68, Ordbend, CA 95943
Sunrise Enterprises, P.O. Box 10058, Elmwood, Conn. 06110-0058
Park Seed Co., Cokesbury Road, Greenwood, SC 29647-0001
Shephens, James. Minor Vegetables. Univ. of Florida Cooperative Extension Bulletin SP-40. June 1988, 123 pp.
Yamaguchi, Mas. World Vegetables. AVI Publishing Company, Inc. Westport, Conn. 1983. 415 pp.
Harrington, Geri. Grow Your Own Chinese Vegetables. Garden Way Publishing, Pownal, Vermont. 1984. 268 pp.
Park, H.G. "Suggested Cultural Practices for Mung Bean." Asian Vegetable Research and Development Center, Guide 78-63. Taiwan. April, 1978. 2 pp.
Smith, Francis L. "Mung Beans in California." University of California,
Agricultural Experiment Station, Berkeley. May 1945. 4 pp.
Murray, Mike. "1986 Colusa County Mung Bean Nitrogen Fertilizer Field Test Results." Colusa County Cooperative Extension, P.O. Box 180, Colusa, CA 95932. 1986. 6 pp.
Sandoval, Rick. "Mung Beans Sprout Hope for Solano Diversity." Ag Alert, August 6, 1986. pp. 12-13.
Clement, Lawrence. "1986-87 Results of Dry Bean Production Studies in Solano County." Solano County Cooperative Extension. 26 pp.
Mackie, W. W. "The Mung Bean in California." San Joaquin County Cooperative Extension. Feb. 1943. 2 pp.
By Carrie Young, Sacramento Valley Milling, Inc.; Mike Murray, UCCE Colusa County; Lawrence Clement, UCCE Solano County; and Claudia Myers, UC Small Farm Center.
Reviewed by Steve Temple, 11/89
Reviewed by Carrie Young
Reviewed by Mike Murray
Reviewed by Larry Clement
Figure 1. The 18 to 36 inch tall mung bean plant produces clusters of 3 to 4 inch long pods. Each pod may contain as many as 15 small seeds. (Photo by I-Mo Fu).