Cowpea, black-eyed pea, Vigna unguiculata

The cowpea, also known as the black-eyed pea, is reminiscent of an eye, as the seeds are usually beige and have a dark spot around the navel.

Bean pods up to 90 cm long

The cowpea is an annual crop and grows very variably. There are climbing varieties and varieties that grow herbaceous or bushy. Some varieties can do both: depending on the climate and weather conditions, they grow either by climbing or become bushy. The white, yellow, red, light blue or purple flowers attract various insects. The plants can penetrate the soil deeply. Just eight weeks after sowing, the taproot can be over two meters deep. The pods can also become quite long – depending on the variety. The pods of the asparagus bean subspecies are particularly long, with pods that can grow up to 90 cm long. Just like the pods, the seeds also vary in size, shape and color. There are beige, green, red, brown or black beans. A characteristic feature of the cowpea is the area around the navel, which is usually a different color to the rest of the seed.

Important component of mixed cultures

The cowpea is native to Africa and was domesticated in sub-Saharan Africa over 8500 years ago. It spread in warm areas in Europe and Asia until 400 BCE. Through colonisation and the slave trade, the cowpea later also reached America. Today it can be found in tropical and warm regions on every continent except Antarctica.

The cowpea is a heat-resistant and drought-tolerant crop and is integrated into agriculture in a variety of ways due to its positive effects on agricultural land, such as its ability to bind nitrogen from the air. Smallholder farmers in particular grow cowpea in mixed cultivation with maize, sorghum or millet, thereby producing a secure source of food for their families. Almost 95 percent of global production takes place in West Africa.

Use of the whole plant

The cowpea is an important food, especially as a subsistence crop for people on the African continent. And it is not only the peas, which are eaten fresh or dried, that are edible. The leaves are also used as a herb in soups. The unripe pods are used in South East Asia as a pod vegetable. The leaves are also fed to animals as high-quality fodder.

But the cowpea is not only grown as food and fodder. Certain varieties are also grown for erosion control or as green manure. With 20 to 30 percent protein in the dried peas, the cowpea is an important source of protein. The leaves also contain a similar amount of protein, which is why they are so popular as animal feed. Cowpeas also contain other important micronutrients, such as folic acid, which is particularly important during pregnancy.

Fighting climate change with the cowpea

The main area of cowpea cultivation in sub-Saharan Africa overlaps with areas predicted to experience more food insecurity due to climate change and the associated prolonged drought and increased heat. As the cowpea is drought and heat tolerant, it could play an important role in local food security in the future.

Sources

Herniter et al (2020): Genetic, textual, and archeological evidence of the historical global spread of cowpea(Vigna unguiculata [L.] Walp.). Link.
Uni Gießen: Cowpea, black-eyed pea(Vigna unguiculata [L.] Walp. ssp. unguiculata [= V. sinensis [L.] Walp.]). Link.