The Rice Bean is a legume, native of Southeast Asia where it is still widely cultivated. It is a pulse crop (grown for its dried edible seeds) and is well known in the tropics where there is great variability.
Farmers in northeastern and eastern India commonly eat the green pods raw and cooked as a vegetable. Unripe seeds are boiled and sold as snacks in the village markets. Dried Rice Beans are cooked and combined with rice in many dishes. After harvest, the plants and pods are fed to cattle. Since the growth habit of the Rice Bean is a vigorous vine, it has been used as a barrier when trellised, and a cover crop to prevent weed growth and control erosion. In these cases, the vines need frequent pruning and the cut vines should be left in the field as green mature.
This crop is grown on a rotational schedule with other crops like maize, millets and rice or as a kitchen garden crop for family use. Most varieties are vines with hairy stems, leaves and pods. Because of its adaptability to severe tropical conditions such as drought, high temperatures, humidity, poor soil and a preference for short days needed for flowering, Rice Bean is a valuable source of protein for both humans and livestock in the tropical lowlands. It will not succeed in waterlogged soil.
Harvesting and Seed Production
All the pods generally mature at one time (60-150 days) so one harvest is all that is needed. As the dry pods tend to shatter, (break open and expel the seeds), harvesting either by hand or machine should be done in the morning or when moisture is in the air.
Pests and Diseases
The common enemy of the pulse crops is the root-knot nematode. Planting resistant varieties and rotating with other crops can lessen damage. Interplanting with flowering marigolds has been tried. Rice Bean is resistant to insects including the bean fly.
Cooking and Nutrition
After 40-60 days the young leaves and immature pods are steamed for eating as vegetables. Rice Bean is also an acceptable substitute for soybean sprouts. The beans contain 20% - 22% protein and high amounts of calcium and carbohydrates (60%). A toxic substance in Rice Beans can be eliminated by boiling them and discarding the water.