Know your Cowpea
Know your Cowpea - Introduction
The Cowpea (Vigna unguiculata), aka Field Pea, is one of several species of the widely cultivated genus Vigna.
Four cultivated subspecies are recognised:
Vigna unguiculata subsp. cylindrica Catjang
Vigna unguiculata subsp. dekindtiana African Cowpea
Vigna unguiculata subsp. sesquipedalis Yardlong bean
Vigna unguiculata subsp. unguiculata Black-eyed pea
Cowpeas are one of the most important food legume crops in the semi-arid tropics covering Asia, Africa, southern Europe and Central and South America.
Know your Cowpea - Common names
Cowpea, crowder pea, clack-eyed pea, couthern pea, atimbawini, boeme, boontjie, catjang, caupí, frijol de vaca, field pea, imbumba, isihlumaya.
A subcategory of field peas is crowder peas, so called because they are crowded together in their pods, causing them to have squarish ends.
Know your Cowpea - Botany
It is a herbaceous, prostrate, climbing, or sub-erect to erect legume, growing 15-80 cm high.
Erect and bushy to prostrate and creeping growth habits exist depending on cultivar and growing conditions.
Cowpeas develop strong root systems that have many spreading laterals in the surface soil.
The stems have circular sections and are pock marked. They are sometimes slightly grooved and are glabrous. The texture is fibrous and hard, firm and not inflated when young.
Leaves are alternate and trifoliolate and the leaflets are oval, pointed (6-15 cm x 4-11 cm). They are generally entire and sometimes lobed.
Genotypes vary in the degree of pubescence, but all cultivated cowpeas are less glabrous than other legumes such as common bean and soybean.
Stipules are spurred at the base, stipels are hardly visible.
Inflorescence racemose, flowers white, cream, yellow, mauve or purple.
Pods usually occur in pairs forming a V, and are non-dehiscent.
Pod orientation is mostly pendant and vertical.
Pod length ranges from 6.5-25 cm and the width ranges from 3-12 mm.
Under warm conditions, pod development is rapid and may take only two weeks from pollination to pod maturation.
Each pod holds from 8 to 20 seeds in a crowded orientation.
Seed length is between 6-11 mm and the width is from 4-9 mm. The testa colour also varies from white, pinky-white, pink, tan, brown, and black. The hylum is often ringed black or brown, strongly contrasting with the shade of the testa and hence the name "blackeyed beans" of the Antilles.
It is susceptible to frost.
It is an annual. Some cowpea varieties may start flowering 30 days after sowing and are ready for harvest of dry seeds 25 days later; others may take more than 90 days to flower, and 210-240 days to mature.
Know your Cowpea - Uses
Cowpea is one of the most important grain legumes in Africa and in parts of the Americas and Asia.
In addition to its dry grain, fresh-shelled 'peas', fresh pods, and fresh and dried leaves and flowers are consumed in some regions.
The plant is used as cut and carry forage, and for hay and silage.
Cowpea forms highly effective associations with a wide range of native nitrogen fixing strains of Rhizobium bacteria and with mycorrhizae that allows the species to tolerate poor soils.
Used as a green manure, it can be incorporated into the soil 8-10 weeks after sowing, and can provide the equivalent of 80 kg/ha N to a subsequent crop.
Know your Cowpea - Origins
It is native of West Africa and cultivated throughout the tropics and subtropics between 40ºN and 30ºS at elevations between sea level and 2,000 metres.
Occurs in areas with annual rainfall between 400-2000 mm and summer temperatures between 25-35°C.
Know your Cowpea - Cultivation
Found on a wide range of very acid (pH 4) to strongly alkaline also low-fertility soils from sands to heavy, well-drained clays, with a preference for lighter soils.
A drought-tolerant and warm-weather crop, cowpeas are well-adapted to the drier regions of the tropics, where other food legumes do not perform well.
It does not tolerate extended flooding or salinity.
Most cowpea accessions exhibit classic short-day responses with respect to time of flowering, although a range of sensitivities occur and the effect is modulated by temperature.
It is mainly autogamous and in most environments out-crossing is low (less than 5%), but in the presence of bumble bees or other large insects, out-crossing can be much higher.
Flowers open early in the morning, close by noon and may fall off during the same day.
It also has the useful ability to fix atmospheric nitrogen through its root nodules, and it grows well in poor soils with more than 85% sand and with less than 0.2% organic matter and low levels of phosphorus.
In addition, it is shade tolerant, and therefore, compatible as an inter-crop with maize, millet, sorghum, sugar-cane, and cotton.
This makes cowpea an important component of traditional inter-cropping systems, especially in the complex and elegant subsistence farming systems of the dry savannah in sub-Saharan Africa.
Know your Cowpea - Cuisine
Cowpeas are a common food item in the southern United States, where they are often called field peas.
In Gujarati, these are called Chola/Chowla(ચોળા). In Marathi, these are called Chawali/Chavali(चवळी). (Kārāmani or Kārāmani Payir or Thatta Payir Tamil) are an integral part of the cuisine in southern region of India.
In Tamilnadu during the Tamil month of Maasi (February) - Panguni (March) called Kozhukattai/Adai (steamed sweet cake) prepared with cooked and mashed cowpea bean mixed with jaggery, ghee and other sub ingredients.
In Hindi, it is called 'Lobhia'.
According to the USDA food database, cowpeas have the highest percentage of calories from protein among vegetarian foods.
