The average percentage composition is: With man, on an average, 90 per cent of the dry matter is digestible; 80 per cent of the pro tein; 96 per cent of the nitrogen-free extract; and 80 per cent of the ether extract. String beans or green shell beans are usually boiled and served in various ways. In composition they compare favorably with other vegetables. Dry beans ate baked with salt pork or beef and used for soups and other dishes. They are a cheap, nutritious food, rich in starch and in the proteid, legumin; hence they may be used to replace meat in the diet. If the skins are removed they are easier of digestion and are not so liable to cause flatulency; the latter is due to the production of methane by fermentation in the intestines. Shell- and string-beans are preserved by evaporation or canning. String beans are also preserved with salt. .Cooked dry beans are canned. Bean flour consists of beans ground. Bean meal is used in Europe as feed for horses, cattle and hogs. Bean cake is the residue after the oil has been extracted; it is fed to cattle in northern China. Bean curd is eaten by the natives of northern China.
Bean Pod-rust; anthracnose (Colletotrichum lindemuthianum), a fungus which attacks the stems, leaves and fruit. The disease may be carried over in the seed, the affected ones being recognized by the -yellow or brown discoloration. A black discoloration with ensuing brittleness marks the progress of the disease on the leaves. The selection of sound seed, immediate removal of infected plants and spraying with Bordeaux mixture are recommended. The bean-rust (Udomyces phaseoli) appears as small brown, nearly circu lar and slightly elevated dots on the leaves. These discharge a brown powder, the spores of the disease. Spraying with Bordeaux mix ture is recommended. Blight (Phytophthora phaseoli) attacks the Lima bean. Spraying with copper compound is recommended. The bean-weevil (Bruchus obtectus) may injure the beans when stored. After harvesting, treat the seed two or three times, at intervals of three or four weeks, with carbon bisulphide.
Consult De Candolle, (Nativity of the Bean); Gray and Trumbull, "Origin of Cultivated Plants,0 American Journal of Science, XXVI, 130; Bailey, 'Standard Cyclopedia of Horti culture.)