Legumes
Senior 2 · Agriculture
Legumes
Lesson 1 of 4
16 min
Let's begin
In most Rwandan homes, a meal without beans hardly counts as a meal. Beans are grown by almost every rural household and eaten almost every day, often with sweet potatoes, cassava, bananas or maize. Along with peas, soybean and groundnuts, beans belong to one of the most useful plant families in agriculture: the legumes.
This lesson explains what makes a plant a legume, the names of the legumes grown in Rwanda, and the different groups farmers use them in.
A legume is a plant of the pea family, Fabaceae (also called Leguminosae), or the fruit or seed of such a plant. Legumes share two key features:
A pulse is a legume grown for its dry seed, such as dry beans, peas and chickpeas.
| Common name | Kinyarwanda | Scientific name | Main use |
|---|---|---|---|
| Common bean | ibishyimbo | Phaseolus vulgaris | Dry grain (staple); green pods as a vegetable |
| Garden pea | amashaza | Pisum sativum | Dry and green peas, mainly in cooler highlands |
| Soybean | soya | Glycine max | Grain for flour, milk and oil; cake for animal feed |
| Groundnut (peanut) | ubunyobwa | Arachis hypogaea | Nuts for food, paste and oil |
| Cowpea, pigeon pea, lablab | Vigna, Cajanus, Lablab | Grain and leaves, mainly in drier, warmer areas | |
| Desmodium, calliandra, leucaena | Desmodium, Calliandra, Leucaena | Livestock fodder, soil cover, agroforestry |
By use:
By growth habit (important for beans):
Rwandan research has also released high-iron bean varieties, bred to help reduce anaemia in families that eat beans every day.
Question: Classify each crop by its main use and say whether it is a pulse: (a) dry beans grown for sale in Musanze market; (b) soybean grown for a feed factory; (c) calliandra hedges cut for a Girinka cow; (d) mucuna grown and dug into a tired field.
(a) Grain legume, and a pulse (grown for dry seed eaten by people).
(b) Oil legume. Its oil is extracted and the remaining cake is fed to animals. It is usually not called a pulse because it is grown mainly for oil.
(c) Tree (fodder) legume, not a pulse.
(d) Green manure or cover crop, not a pulse.
Tip
Memory hook: every legume has "a pod and a partner": a pod that splits along two seams, and a bacterial partner (Rhizobium) in its root nodules.
Exam technique: when asked for "types of legumes", state the basis of your classification first ("by use" or "by growth habit") and then give an example of each type.
Define a legume.
Solution: A plant of the pea family (Fabaceae), or its fruit or seed, whose fruit is a pod that splits along two seams; most legumes have root nodules containing nitrogen-fixing bacteria.
Give the Kinyarwanda name and the scientific name of the common bean.
Solution: Ibishyimbo; Phaseolus vulgaris.
Name two oil legumes.
Solution: Soybean and groundnut.
Give two differences between bush beans and climbing beans.
Solution: Any two: bush beans are short and need no support, climbing beans need stakes; climbing beans flower and bear for longer; climbing beans give higher yields per area; bush beans mature faster.
Why are climbing beans popular in the Northern Province highlands?
Solution: Farms there are small and steep, and the climate is cool and wet, which suits climbing beans. Their high yield per area makes the best use of scarce land.
Summary
Sources and credits
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
