Faba bean (Vicia faba)

Faba bean is one of the oldest dual-use food and fodder species. The beans are rich in minerals (calcium, phosphorus) and vitamins. Containing approximately 26% protein, 2% fat, and 50% carbohydrate, faba bean is considered in some regions to be superior to field peas or other legumes as a human food source. It is one of the most important winter crops in the Middle East.

Vicia faba is commonly referred to as fava bean, broadbean, horsebean, field bean or faba bean. It is believed to have originated in southwest Asia or around the Mediterranean and is now cultivated throughout Europe, Africa, Central Asia and the Americas

Faba bean is a cool season legume, growing well in temperate regions as well as the highland tropics. It can be seeded in early spring as soon as the soil is tillable in temperate areas. More hardy than the garden pea, it will survive temperatures as low as -10°C (15°F). Optimal temperature ranges from 13-27°C (55-80°F). It also grows especially well at high elevations (1200-3500 meters / 4000-11,500 feet) in the subtropics and tropics as a “winter crop.” However, it is not well suited to the humid lowland tropics, where it may flower but fails to set seed. Although faba bean is not a very drought-resistant legume crop, ICARDA (International Center for Agricultural Research in Dry Areas) has developed cultivars with higher water use efficiency. Faba bean requires an average annual rainfall of 700-1000 mm (28-40 inches), will grow in moderate soil types, and is more tolerant of acidic soil conditions than most other legumes.

The large-seeded varieties produce 1 or 2 pods at each node while the small-seeded types can bear 2-5 pods. The pods are up to 18 inches long and contain 3-12 large beans. There are about 15 pods per stalk on the large types and 60 pods on plants of the small-seeded varieties.

This annual crop provides good ground cover during the first 75-90 days of growth, flowers in 80-90 days and produces mature seed at 100-150 days after planting. However, note that the onset of flowering is largely dependent on environmental conditions (temperature, photoperiod), and may range from 1 month to 7 or 8 months

Faba bean can be grown alone or intercropped with other food crops. A large percentage of world cultivation of faba bean comes from China where it is often intercropped with wheat, cotton or barley. In Ethiopia it is intercropped with pea, while Egyptians grow faba beans amongst their sugarcane

Faba bean pods can be eaten as a vegetable at an immature stage, cooked or raw. The young, tender beans can also be boiled, but the indigestible skin of the bean must be peeled before eating at this stage. Mature seeds can be baked and eaten like a peanut or ground to be added to soups. Some popular dishes of faba bean include medamis (stewed beans), falafel (Middle-eastern dish made by deep frying the cotyledon paste, added to vegetables and spices), bissara (cotyledon paste poured onto plates) and nabet soup (boiled germinated beans). It can also be used as a coffee extender when roasted and ground. Caution: Consumption of immature, partially cooked faba beans or inhalation of pollen can result in a form of anemia known as “favism” for a small percentage of the population genetically predisposed to the condition. The toxic compounds that trigger the onset of this condition can be neutralized by soaking the beans before cooking.

Faba bean also makes excellent animal forage for poultry, pigs or cattle. Faba bean straw, for instance, is also a good feed with high protein content (5–20%) and digestibility (50% of the dry matter). The high tannin levels of the seeds (up to 9%) create a bitter taste when fed raw to animals, but cultivars have been developed with low tannin content (1%) and high digestibility. The seeds can be pulverized and added to a feed ration. The leaves serve as a good source of protein and energy. This legume can also be used as a green manure to improve fertility in marginal soil. Faba bean plays a key role in managing soil fertility as a rotation crop; it is often grown in rotation with cereals, especially with wheat or barley.

It is best to harvest the pods just before full maturity to prevent the pods from shattering and/or rotting. Cut the plants in early morning or late evening to avoid the hottest part of the day. The harvested material can be gathered in small piles and left to dry for a few days. To collect the seeds, thresh the plants with a stick or allow animals to tramp them. Seeds with moisture content of 11-14% can be stored for 2-7 years at 5-10°C (40-50°F) or 1-4 years at 10-20°C (50-70°F).

With respect to nitrogen fixation, faba bean plant roots are effectively nodulated by Rhizobium leguminosarum. In a study conducted in several locations in the southeastern Ethiopian highlands, faba bean inoculated with this bacteria fixed between 139-210 kg/ha (124-187 lb/acre) of nitrogen (see previous article in this issue on inoculation of legumes).

Two common fungal diseases, chocolate spot and rust, have caused up to 50% yield losses in Egypt. Faba bean is known to be susceptible to various viral diseases, including bean yellow mosaic virus, bean leaf roll, and broad bean stain virus. However, several new breeds have been developed with resistance to all these diseases