Bean

Scientific Name    Phaseolus vulgaris L.

Order / Family     Fabales: Fabaceae

Local Names       Maharagwe (Swahili)

Common Names

Bush beans, common beans, dry beans, dwarf beans, field beans, French beans (also known as green beans or snap beans), garden beans, haricot beans, kidney beans, pole beans or string beans

General information

Many names are used for Phaseolus vulgaris. These include bush beans, common beans, dry beans, dwarf beans, field beans, French beans, garden beans, green beans, haricot beans, kidney beans, pole beans, snap beans or string beans. 

However, presently, two distinct bean types are recognised in the region: French beans (green beans) and common beans (dry beans). French beans are the immature green pods of P. vulgaris and are primarily grown for export market to European Union and elite local urban markets. Common beans are the second most important staple food to maize for the local people. 

Beans were introduced to Africa from Latin America several centuries ago. To date beans are a vital staple in Africa, providing the main source of protein. Common beans are mainly grown by women for subsistence and for the local market. French beans (green/snap beans) are grown as a cash crop by large scale and smallholder farmers. They are a major export vegetable commodity in Eastern Africa.

Bush bean in flower

Purple snap bean variety

Runner bean flowers

Pole bean plant with pods

Green bean flowers and pods

Green beans

1.Black Beans

Black beans are a staple in many Mexican and Brazilian dishes. They have a velvety-smooth texture and mild flavor. They also have a lower glycemic index than many other high-carb foods, helping to reduce the spike in blood sugar that occurs after eating a meal.

2. Black-Eyed Peas

This Southern staple has a beige hue with an eye-catching black spot, hence the name "black-eyed peas." They have an earthy flavor that complements salty foods like ham and bacon.

3. Cannellini Beans

Also known as white Italian kidney beans, these cream-colored beans are one of the most common types of beans. They are a popular addition to soups, salads, and many Italian dishes.

 4. Chickpeas (Garbanzo Beans)

They have a round shape and a firm texture, making them a great salad topping.

5. Great Northern Beans

This is another type of white bean that is often mistaken for cannellini or navy beans

6. Kidney Beans

These beans are known for their vibrant red skin and white interior. They have a mild flavor, and make the perfect addition to any chili recipe.

7. Lima Beans

These beans get a bad rap, but there's actually so much to love when it comes to lima beans. They can be white, creamy, or green in color.

8. Pinto Beans

Pinto beans have an orange-pink color with rust-colored specks

9. Fava Beans

Fava beans, or broad beans, can be difficult to work with. They require that you remove them from their pods and then blanch them in order to get the skins off.

10. Navy Beans

This bean goes by many names: haricot, pearl haricot beans, white pea bean, and Boston bean. They have a mild flavor and creamy texture, and similar to Great Northern Beans, they do a great job of absorbing the flavors around them.

11 Adzuki Beans

These small, round red beans , Like other legumes, they're protein-packed and high in fiber.

12. Edamame

Edamame are young soybeans which are usually eaten while still inside the pod.

13. Cranberry Beans

Rounding out the list are these striking cream-colored beans with red speckles. Also known as borlotti beans, cranberry beans have a creamy texture and a nutty flavor.

14. Soybeans

 Soybeans are dried and beige in color.

15. Mung Beans

These beans are one of the most consumed types in the world. They are small, round, and green with a white stripe going through them. They have a mild flavor and a starchy texture

Common beans grow within a range of temperatures of 17.5-27°C. Above 30°C flower buds are likely to fall and seeds are rarely formed at temperatures over 35°C. They are sensitive to night frost. Common beans are usually grown at altitudes between 600 - 1950 m in many tropical areas. A moderate well-distributed rainfall is required (300-400 mm per crop cycle) but dry weather during harvest is essential. Drought or waterlogging are harmful. Climbing cultivars will give economic yields in areas of high rainfall but the dwarf types appear to be more sensitive to high soil moisture levels. Suitable soil types range from light to moderately heavy and to peaty soils with near-neutral pH and good drainage. Common bean is susceptible to salinity.

The optimum temperature range for growing French beans is 20-25°C, but can be grown in temperatures ranging between 14 and 32°C. Extreme temperatures result in poor flower development and poor pod set. However, French beans mature faster in warmer areas. French beans can be grown between 1000 and 2100 metres above sea level. Rainfed cultivation is possible in areas with well distributed, medium to high annual rainfall (900-1200 mm) but to maintain a continuous production especially during the dry season, irrigation is essential. During the dry season up to 50 mm of water per week is required. This could be applied through furrow or overhead irrigation. French beans grow best on well drained, silty loams to heavy clay soils high in organic matter with pH 5.5-6.5. 

The common bean is used as a pulse and green vegetable eaten fresh or cooked. The beans can be dried, cooked in sauce and canned .The common bean is used as a pulse and green vegetable eaten fresh or cooked. The beans can be dried, cooked in sauce and canned.

Beans are among some of the oldest cultivated vegetables. There are various types of beans that differ with shapes, sizes, taste and nutritional facts. Kidney beans, pinto beans, broad beans, fava beans, lima beans, etc. are some of the different types of beans. Each of them is loaded with dietary fibers, proteins and major vitamins and minerals like vitamin A, vitamin C, potassium, calcium and magnesium. The amount of the above given nutrients varies from one type of bean to other. Beans are very low in fat and cholesterol and they also help to lower the bad cholesterol in the body. Since they are high in proteins, they make an excellent meat substitute for vegetarians. They are extremely low in calories and hence are a favorite food among the calorie conscious people. Before knowing more about beans nutritional value, let us take a look at some figures related to nutrition in beans.

Countries where beans is grown

The main producing countries in the region are Kenya, Tanzania, Uganda, and more recently Rwanda. In Kenya, most of the crop is grown by smallholders and virtually all is exported to Europe. Estimates indicate that up to 50,000 smallholder families are involved in French bean production in Kenya. 

The growth habit of common beans varies from determinate dwarf or bush types to indeterminate climbing or pole cultivars. Bush beans are the most predominant types grown in Africa. However, improved climbing beans introduced to Rwanda in the 80's have since spread to other countries in the region. They are particularly grown in areas with limited land and high human population.

Basic requirements

Common beans are warm-season crops and should be planted after all danger of frost has passed and the soil has warmed. Beans will grow best at soil temperatures between 15.5 and 29°C (60–85°F) and are sensitive to cold temperatures and frosts. Beans will grow best in a fertile, well-draining soil with a pH between 6.0 and 6.75 Beans will perform best in full sunlight.

Sowing seeds

Beans should be direct seeded in the garden in when the soil has reached a temperature of at least 15.5°C (60°F), with the optimum temperature for germination being between 15.5 and 29°C (60–85°F). Planting at cooler temperatures leads to slow germination and promotes seed rotting. Seeds should be planted 2.5–3.5 cm (1–1.5 in) deep. Bush beans should be planted 5–10 cm (2–4 in) apart allowing 0.6–0.9 m ( 2–3 ft) between rows. Pole beans can be planted in both row and hills. In rows, seeds should be spaced 15–25 cm (6–10 in) apart allowing 0.9–1.2 m (3–4 ft) between rows. For a continuous harvest of beans over the summer months, make new plantings every 2–3 weeks.

Poles and trellises

Pole beans should be provided with a pole or trellis to climb on to support the weight of the pods and allow light to penetrate to all parts of the plant, helping to prevent disease. Bean poles should have a rough surface to help the plant to grip and should be 1.8–2.1 m (6–7 ft) long. Three or four poles can be used to form a tripod onto which the plants can be trained. Bean trellises can be constructed easily using posts (or a tripod arrangement of poles), wire and twine. Position a post at either end of the area in which you wish to plant a row of beans and connect with two lengths of wire. The first wire should be approximately 13 cm (5 in) from the ground, and the second 1.5–1.8 m (5–6 ft) from the ground. Finally, use the twine to create a V-shaped trellis by tying the twine to the bottom wire, bringing it up to the top wire and looping it back down around the bottom wire. Continue to zigzag the string all the way along the wires to the second support before tying the twine off. A rough textured twine is best as it will encourage the plant to climb and twine around it. Pinch back the growing tips of the plants once they reach the top support to encourage the plant to branch.

Mulching 

Mulching with straw and cut grasses helps conserve moisture, promote adventitious root development and enhances tolerance to bean fly maggot damage.  

Intercropping

 Beans are excellent for intercropping with other food crops, such as maize, potatoes, celery, cucumber and can help supply the other crops with nitrogen to a limited degree. Longer season varieties of beans can fix higher amounts of nitrogen than short season varieties. Intercropping with chives or garlic helps repel aphids (KIOF - personal communication).  

Water management 

A regular water supply is essential for French beans as moisture affects yields, uniformity and quality. Water stress during flowering reduces yields, as does waterlogging. Irrigation in dry spells is recommended as 35 mm per week at planting and 10 days post emergence, followed by 50 mm per week thereafter till end of production.

Harvesting

Beans are generally ready for harvest approximately two weeks after bloom. The beans should be harvested just before the seeds are mature and before they form bumps on the pod. The pods should be firm and snap when they are bent. Pick beans every 2–3 days to ensure the plants remain productive. Pinch beans rather than pulling to avoid damaging the plant. Cut pole beans from the plant using scissors.

Pole beans planted beneath a trellis

Bean tripod and trellis

CABI Crop Protection Compendium. (2008). Phaseolus vulgaris datasheet. Available at: http://www.cabi.org/cpc/datasheet/40626. [Accessed 06 November 14]. Paid subscription required. Drost, D. (2010). Beans in the Garden . Utah State University Cooperative Extension. Available at: https://extension.usu.edu/files/publications/publication/HG_Garden_2005-08.pdf. [Accessed 06 November 14]. Free to access. Lerner, B. R. (2001). Growing Beans in the Home Vegetable Garden. Purdue University Cooperative Extension Service. Available at: http://www.hort.purdue.edu/ext/ho-175.pdf. [Accessed 06 November 14]. Free to access. Schwartz, H. F., Steadman, J. R., Hall, R. & Forster, R. L. (2005) Compendium of Bean Diseases. Available at: http://www.apsnet.org/apsstore/shopapspress/Pages/43275.aspx. Available for purchase from APS Press.

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https://beaninstitute.com/bean-nutrition-overview/

http://dev.infonet-biovision.org/PlantHealth/Crops/Beans

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