This variety of bean has several synonymous species names. It has been described as a bean “between the cowpea and the mung bean”. Its origins can be traced to Africa and Asia and it has now spread to the tropical and subtropical areas of South America and central and northern Africa.
This is not a commonly cultivated crop though its uses are many. The tubers are eaten by humans or animals. It is a good supplier of nectar for bees and as a cover crop it improves the soil by fixing nitrogen on its roots. It controls erosion by its rapid growth and it is a forage crop for animals.
A benefit of this Vigna species is its rapid growth of vines up to 6 m (20 ft) with abundant foliage. It also is one of the best bean species for tolerating water logged soil for a period of up to six months. The best temperature range for growth is 15°-32°C (60°-90° F). Its yield will improve with nitrogen fertilizer and inoculation with nitrogen-fixing bacteria.
Harvesting and Seed Production
The pods, leaves and stems of the Wild Mung Bean are covered by hairs but this feature does not appear to be problematic. A large piece of cloth may be dragged along under the mature plants when the seed pods are picked to collect the seeds that shatter easily. Dried seeds store well until the following season.
Pests and Diseases
Research is ongoing to transfer the disease resistance of the Wild Mung Bean to the cowpea. Genes for the resistance of weevils, I.L., aphids and some other pests and diseased have been successfully transferred into the cultivated cowpeas.
Cooking and Nutrition
Three parts of the Wild Mung Bean plant are edible as vegetables, the leaves, pods and tubers. When the pods have ripened and begin to show signs of drying or changing color, this signals that the tubers are ripe for digging. The tubers can be eaten raw, boiled or roasted, as a substitute for sweet potatoes. The flesh is smooth and white and contains 14.5 % protein, much higher that the 1% - 7% of sweet potatoes and yams.
Tropical Legumes: Resources for the Future. National Academy of Sciences, Washington, D.C. 1979