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:
- 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.
- 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.