The cowpea (''Vigna unguiculata'') is an

annual Annual may refer to: * Annual publication, periodical publications appearing regularly once per year **Yearbook ** Literary annual * Annual plant * Annual report * Annual giving * Annual, Morocco, a settlement in northeastern Morocco * Annuals (b ...

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

from the genus ''

Vigna ''Vigna'' is a genus of plants in the legume family, Fabaceae, with a pantropical distribution.Aitawade, M. M., et al. (2012)Section ''Ceratotropis'' of subgenus ''Ceratotropis'' of ''Vigna'' (Leguminosae–Papilionoideae) in India with a new ...

''. Its tolerance for sandy soil and low rainfall have made it an important

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponic ...

in the

semiarid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

regions across

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. It requires very few inputs, as the plant's

root nodule Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known a ...

s are able to fix atmospheric nitrogen, making it a valuable crop for resource-poor farmers and well-suited to

intercropping Intercropping is a multiple cropping practice that involves growing two or more crops in proximity. In other words, intercropping is the cultivation of two or more crops simultaneously on the same field. The most common goal of intercropping is ...

with other crops. The whole plant is used as

forage Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...

for animals, with its use as cattle feed likely responsible for its name. Four subspecies of cowpeas are recognised, of which three are cultivated. A high level of morphological diversity is found within the species with large variations in the size, shape, and structure of the plant. Cowpeas can be erect, semierect (

trailing Trailing can mean, among others: * Facing and trailing, in railroads * The act f using a Trailer (promotion) * Trailing wheel * Trailing arm * Trailing edge * Hound trailing * Trailing twelve months Trailing twelve months (TTM) is a measurement of ...

), or

climbing Climbing is the activity of using one's hands, feet, or any other part of the body to ascend a steep topographical object that can range from the world's tallest mountains (e.g. the eight thousanders), to small boulders. Climbing is done fo ...

. The crop is mainly grown for its seeds, which are high in

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

, although the leaves and immature seed pods can also be consumed. Cowpeas were

domesticated Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. A ...

in Africa and are one of the oldest crops to be farmed. A second domestication event probably occurred in Asia, before they spread into Europe and the Americas. The seeds are usually cooked and made into stews and curries, or ground into flour or paste. Most cowpeas are grown on the African continent, particularly in

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

and

Niger ) , official_languages = , languages_type = National languages Insect infestation is a major constraint to the production of cowpea, sometimes causing over 90% loss in yield. The legume pod borer ''

Maruca vitrata ''Maruca vitrata'' is a pantropical insect pest of leguminous crops like pigeon pea, cowpea, mung bean and soybean. Its common names include the maruca pod borer, bean pod borer, soybean pod borer, mung moth, and the legume pod borer. The speci ...

'' is the main preharvest pest of the cowpea and the cowpea weevil ''

Callosobruchus maculatus ''Callosobruchus maculatus'' is a species of beetles known commonly as the cowpea weevil or cowpea seed beetle.Tran, B. M. D. and P. F. Credland. (1995)Consequences of inbreeding for the cowpea seed beetle, ''Callosobruchus maculatus'' (F.) (Cole ...

'' the main postharvest pest.

Taxonomy and etymology

''Vigna unguiculata'' is a member of the ''

'' (peas and beans) genus. ''Unguiculata'' is Latin for "with a small claw", which reflects the small stalks on the flower petals. Common names for cultivated cowpeas include; black-eye pea, southern pea, niebe (alternatively ñebbe), and crowder pea. All cultivated cowpeas are found within the universally accepted ''V. unguiculata'' subspecies ''unguiculata'' classification, which is then commonly divided into four

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

groups: ''unguiculata'', ''biflora'', ''sesquipedalis'', and ''textilis.'' The classification of the wild relatives within ''V. unguiculata'' is more complicated, with over 20 different names having been used and between 3 and 10 subgroups described. The original subgroups of ''stenophylla'', ''dekindtiana'', and ''tenuis ''appear to be common in all taxonomic treatments, while the variations ''pubescens ''and'' protractor'' were raised to subspecies level by a 1993 characterisation.

The first written reference of the word 'cowpea' appeared in 1798 in the United States. The name was most likely acquired due to their use as a

fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food g ...

crop for cows. Black-eyed pea, a common name used for the ''unguiculata'' cultivar group, describes the presence of a distinctive black spot at the hilum of the seed. Black-eyed peas were first introduced to the southern states in the United States and some early varieties had peas squashed closely together in their pods, leading to the other common names of southern pea and crowder pea. The ''sesquipedalis'' subspecies arrived in the United States via Asia. It is characterised by unusually long pods, leading to the Latin name (''sesquipedalis'' means "foot and a half long") and the common names of yardlong bean, asparagus bean, and Chinese long-bean. Vigna unguiculata varieties

Description

A large morphological diversity is found within the crop, and the growth conditions and grower preferences for each variety vary from region to region. However, as the plant is primarily

self-pollinating Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to ...

, its

genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is dis ...

within varieties is relatively low. Cowpeas can either be short and bushy (as short as ) or act like a vine by climbing supports or trailing along the ground (to a height of ). The

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproo ...

can penetrate to a depth of after eight weeks. The size and shape of the leaves vary greatly, making this an important feature for classifying and distinguishing cowpea varieties. Another distinguishing feature of cowpeas is the long peduncles, which hold the flowers and seed pods. One peduncle can support four or more seed pods. Flower colour varies through different shades of purple, pink, yellow, and white and blue. Seeds and seed pods from wild cowpeas are very small, while cultivated varieties can have pods between long. A pod can contain six to 13 seeds that are usually kidney-shaped, although the seeds become more spherical the more restricted they are within the pod. Their texture and colour are very diverse. They can have a smooth or rough coat and be speckled, mottled, or blotchy. Colours include white, cream, green, red, brown, and black, or various combinations.

History

Compared to most other important crops, little is known about the

domestication Domestication is a sustained multi-generational relationship in which humans assume a significant degree of control over the reproduction and care of another group of organisms to secure a more predictable supply of resources from that group. ...

, dispersal, and cultivation history of the cowpea. Although there is no

archaeological evidence The archaeological record is the body of physical (not written) evidence about the past. It is one of the core concepts in archaeology, the academic discipline concerned with documenting and interpreting the archaeological record. Archaeological ...

for early cowpea cultivation, the

centre of diversity A center of origin is a geographical area where a group of organisms, either domesticated or wild, first developed its distinctive properties. They are also considered centers of diversity. Centers of origin were first identified in 1924 by Ni ...

of the cultivated cowpea is West Africa, leading an early consensus that this is the likely centre of origin and place of early domestication. New research using

molecular marker A molecular marker is a molecule, sampled from some source, that gives information about its source. For example, DNA is a molecular marker that gives information about the organism from which it was taken. For another example, some proteins can be ...

s has suggested that domestication may have instead occurred in East Africa and currently both theories carry equal weight. While the date of cultivation began may be uncertain, it is still considered one of the oldest domesticated crops. Remains of charred cowpeas from rock shelters in Central Ghana have been dated to the

2nd millennium BC The 2nd millennium BC spanned the years 2000 BC to 1001 BC. In the Ancient Near East, it marks the transition from the Middle to the Late Bronze Age. The Ancient Near Eastern cultures are well within the historical era: The first half of the mil ...

. In 2300 BC, the cowpea is believed to have made its way into Southeast Asia, where secondary domestication events may have occurred. From there they traveled north to the Mediterranean, where they were used by the Greeks and Romans. The first written references to the cowpea were in 300 BC and they probably reached Central and North America during the

slave trade Slavery and enslavement are both the state and the condition of being a slave—someone forbidden to quit one's service for an enslaver, and who is treated by the enslaver as property. Slavery typically involves slaves being made to perf ...

through the 17th to early 19th centuries.

Cultivation

Black-eyed pea pods on plant in Hong Kong

Cowpeas thrive in poor dry conditions, growing well in soils up to 85% sand. This makes them a particularly important crop in arid, semidesert regions where not many other crops will grow. As well as an important source of food for humans in poor, arid regions, the crop can also be used as feed for livestock. Its

nitrogen-fixing Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmos ...

ability means that as well as functioning as a sole crop, the cowpea can be effectively

intercropped Intercropping is a multiple cropping practice that involves growing two or more crops in proximity. In other words, intercropping is the cultivation of two or more crops simultaneously on the same field. The most common goal of intercropping is ...

with

sorghum ''Sorghum'' () is a genus of about 25 species of flowering plants in the grass family (Poaceae). Some of these species are grown as cereals for human consumption and some in pastures for animals. One species is grown for grain, while many othe ...

millet Millets () are a highly varied group of small-seeded grasses, widely grown around the world as cereal crops or grains for fodder and human food. Most species generally referred to as millets belong to the tribe Paniceae, but some millets al ...

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...

cassava ''Manihot esculenta'', common name, commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively ...

, or

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor perce ...

The optimum temperature for cowpea growth is , making it only available as a summer crop for most of the world. It grows best in regions with an annual rainfall between . The ideal soils are sandy and it has better tolerance for infertile and acid soil than most other crops. Generally, for the erect varieties and for the climbing and trailing varieties. The seeds can be harvested after about 100 days or the whole plant used as forage after about 120 days. Leaves can be picked from 4 weeks after planting. These characteristics, along with its low

fertilisation Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

requirements, make the cowpea an ideal crop for resource-poor farmers living in the

Sahel The Sahel (; ar, ساحل ' , "coast, shore") is a region in North Africa. It is defined as the ecoclimatic and biogeographic realm of transition between the Sahara to the north and the Sudanian savanna to the south. Having a hot semi-arid c ...

region of West Africa. Early-maturing varieties of the crop can thrive in the

semiarid climate A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

, where rainfall is often less than . The timing of planting is crucial, as the plant must mature during the seasonal rains. The crop is mostly intercropped with

pearl millet Pearl millet (''Cenchrus americanus'', commonly known as the synonym ''Pennisetum glaucum''; also known as 'Bajra' in Hindi, 'Sajje' in Kannada, 'Kambu' in Tamil, 'Bajeer' in Kumaoni and 'Maiwa' in Hausa, 'Mexoeira' in Mozambique) is the most w ...

, and plants are selected that provide both food and fodder value instead of the more specialised varieties. Storage of the seeds can be problematic in Africa due to potential infestation by postharvest pests. Traditional methods of protecting stored grain include using the insecticidal properties of

Neem ''Azadirachta indica'', commonly known as neem, nimtree or Indian lilac, is a tree in the mahogany family Meliaceae. It is one of two species in the genus ''Azadirachta'', and is native to the Indian subcontinent and most of the countries in Afr ...

extracts, mixing the grain with ash or sand, using vegetable oils, combining ash and oil into a soap solution or treating the cowpea pods with smoke or heat. More modern methods include storage in airtight containers, using gamma irradiation, or heating or freezing the seeds. Temperatures of kill the weevil larvae, leading to a recent push to develop cheap forms of solar heating that can be used to treat stored grain. One of the more recent developments is the use a cheap, reusable double-bagging system (called PICs) that asphyxiates the cowpea weevils.

Pests and diseases

Insects are a major factor in the low yields of African cowpea crops, and they affect each tissue component and developmental stage of the plant. In bad infestations, insect pressure is responsible for over 90% loss in yield. The legume pod borer, ''

,'' is the main preharvest pest of the cowpea. Other important pests include pod sucking bugs,

thrips Thrips ( order Thysanoptera) are minute (mostly long or less), slender insects with fringed wings and unique asymmetrical mouthparts. Different thrips species feed mostly on plants by puncturing and sucking up the contents, although a few are ...

aphids Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

and the post-harvest cowpea weevil, ''

''. ''M. vitrata'' causes the most damage to the growing cowpea due to their large

host range In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include a ...

and

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

. It causes damage to the flower buds, flowers, and pods of the plant, with infestations resulting in a 20–88% loss of yield. While the insect can cause damage through all growth stages, most of the damage occurs during flowering.

Biological control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...

has had limited success, so most preventive methods rely on the use of

agrichemicals An agrochemical or agrichemical, a contraction of ''agricultural chemical'', is a chemical product used in industrial agriculture. Agrichemical refers to biocides ( pesticides including insecticides, herbicides, fungicides and nematicides) an ...

Genetically modified Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the gene ...

cowpeas has been developed to express the

cry protein Delta endotoxins (δ-endotoxins) are pore-forming toxins produced by '' Bacillus thuringiensis'' species of bacteria. They are useful for their insecticidal action and are the primary toxin produced by Bt maize/corn. During spore formation ...

from ''

Bacillus thuringiensis ''Bacillus thuringiensis'' (or Bt) is a gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide. ''B. thuringiensis'' also occurs naturally in the gut of caterpillars of various types of moths and butterflie ...

'', which is toxic to

lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

n species including the maruca. BT Cowpea was commercialised in Nigeria in 2019. CSIRO ScienceImage 489 Cowpea bean varieties infested with weevils

CSIRO ScienceImage 489 Cowpea bean varieties infested with weevils

Severe ''C. maculatus'' infestations can affect 100% of the stored peas and cause up to 60% loss within a few months. The

weevil Weevils are beetles belonging to the Taxonomic rank, superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and Herbivore, herbivorous. Approximately 97,000 species of weevils are known. They b ...

generally enters the cowpea pod through holes before harvest and lays eggs on the dry seed. The larvae burrow their way into the seed, feeding on the

endosperm The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the embryo and ...

. The weevil develops into a sexually mature adult within the seed. An individual bruchid can lay 20–40 eggs, and in optimal conditions, each egg can develop into a reproductively active adult in 3 weeks. The most common methods of protection involve the use of insecticides, the main pesticides used being

carbamates In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formally obta ...

, synthetic

pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and ''Chrysanthemum coccineum, C. coccineum''). Pyrethroids are used as commercial and hou ...

s, and

organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered a ...

s. Cowpea is susceptible to

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

, fungal, bacterial, and virus diseases, which can result in substantial loss in yield. Common diseases include

blight Blight refers to a specific symptom affecting plants in response to infection by a pathogenic organism. Description Blight is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organ ...

s, root rot, wilt,

powdery mildew Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of ascomycete fungi in the order Erysiphales. Powdery mildew is one of the easier plant diseases to identify, as ...

, root knot,

rust Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH ...

and

leaf spot A leaf spot is a limited, discoloured, diseased area of a leaf that is caused by fungal, bacterial or viral plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides. These discoloured spots or lesions ...

. The plant is susceptible to

mosaic virus A mosaic virus is any virus that causes infected plant foliage to have a mottled appearance. Such viruses come from a variety of unrelated lineages and consequently there is no taxon that unites all mosaic viruses. All the symptoms of each virus ...

es, which cause a green mosaic pattern to appear in the leaves. The cowpea mosaic virus (CPMV), discovered in 1959, has become a useful research tool. CPMV is stable and easy to propagate to a high yield, making it useful in

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

development and protein expression systems. One of the plant's defenses against some insect attacks is the cowpea

trypsin inhibitor A trypsin inhibitor (TI) is a protein and a type of serine protease inhibitor (serpin) that reduces the biological activity of trypsin by controlling the activation and catalytic reactions of proteins. Trypsin is an enzyme involved in the breakdown ...

(CpTI). CpTI has been transgenically inserted into other crops as a pest deterrent. ''CpTI'' is the only gene obtained outside of ''B. thuringiensis'' that has been inserted into a commercially available genetically modified crop. Besides biotic stresses, cowpea also faces various challenges in different parts of the world such as drought, heat, and cold. Drought lowers the growth rate and development, ultimately reducing yield, although cowpea is considered more drought tolerant than most other crops. Drought at the preflowering stage in cowpea can reduce the yield potential by 360 kg/ha. Crop wild relatives are the prominent source of genetic material, which can be tapped to improve biotic/abiotic tolerance in crops.

International Institute of Tropical Agriculture The International Institute of Tropical Agriculture (IITA) is a nonprofit organization that works with partners to enhance crop quality and productivity, reduce producer and consumer risks, and generate wealth from agriculture, with the ultimate ...

(IITA), Nigeria and Institut de l’Environment et de Recherches Agricoles are looking to tap into the genetic diversity of wild cowpeas and transfer that into cultivars to make them more tolerant to different stresses and adaptive to climate change.

Culinary use

Cowpeas are grown mostly for their edible beans, although the leaves, green seeds and pods can also be consumed, meaning the cowpea can be used as a food source before the dried peas are harvested. Like other

s, cowpeas are cooked to make them edible, usually by boiling. Cowpeas can be prepared in stews, soups, purees, casseroles and curries. They can also be processed into a paste or flour. Chinese long beans can be eaten raw or cooked, but as they easily become waterlogged are usually sautéed, stir-fried, or deep-fried. A common snack in Africa is ''koki'' or ''moin-moin'', where the cowpeas are mashed into a paste, mixed with spices and steamed in banana leaves. They also use the cowpea paste as a supplement in

infant formula Infant formula, baby formula, or simply formula (American English); or baby milk, infant milk or first milk (British English), is a manufactured food designed and marketed for feeding to babies and infants under 12 months of age, usually prepar ...

when weaning babies off milk. Slaves brought to America and the West Indies cooked cowpeas much the same way as they did in Africa, although many people in the

American South The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...

considered cowpeas not suitable for human consumption. A popular dish was

Hoppin' John Hoppin' John, also known as Carolina peas and rice, is a peas and rice dish served in the Southern United States. It is made with cowpeas (mainly, Black-eyed peas, Sea Island red peas in the Sea Islands and Iron and clay peas in the Southeast US) ...

, which contained black-eyed peas cooked with rice and seasoned with pork. Over time, cowpeas became more universally accepted and now Hoppin' John is seen as a traditional Southern dish ritually served on New Year's Day.

Nutrition and health

Cowpea seeds provide a rich source of proteins and

food energy Food energy is chemical energy that animals (including humans) derive from their food to sustain their metabolism, including their muscle, muscular activity. Most animals derive most of their energy from aerobic respiration, namely combining the ...

, as well as minerals and vitamins. This complements the mainly

cereal A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...

diet in countries that grow cowpeas as a major food crop. A seed can consist of 25% protein and has very low fat content. Cowpea

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

is digested more slowly than the starch from cereals, which is more beneficial to human health. The grain is a rich source of

folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and ...

, an important vitamin that helps prevent

neural tube defect Neural tube defects (NTDs) are a group of birth defects in which an opening in the spine or cranium remains from early in human development. In the third week of pregnancy called gastrulation, specialized cells on the dorsal side of the embryo ...

s in unborn babies. The cowpea has often been referred to as "poor man's meat" due to the high levels of protein found in the seeds and leaves. However, it does contain some antinutritional elements, notable

phytic acid Phytic acid is a six-fold dihydrogenphosphate ester of inositol (specifically, of the ''myo'' isomer), also called inositol hexakisphosphate (IP6) or inositol polyphosphate. At physiological pH, the phosphates are partially ionized, resulting ...

and

protease inhibitors Protease inhibitors (PIs) are medications that act by interfering with enzymes that cleave proteins. Some of the most well known are antiviral drugs widely used to treat HIV/AIDS and hepatitis C. These protease inhibitors prevent viral replicat ...

, which reduce the nutritional value of the crop. Methods such as fermentation, soaking, germination, debranning, and autoclaving are used to combat the antinutritional properties of the cowpea by increasing the bioavailability of nutrients within the crop. Although little research has been conducted on the nutritional value of the leaves and immature pods, what is available suggests that the leaves have a similar nutritional value to

black nightshade Black nightshade is a common name for several plants and may refer to: * '' Solanum americanum'' (American black nightshade) of much of North America * ''Solanum nigrum'' (European black nightshade) of Europe * '' Solanum ptychanthum'' (Eastern bla ...

and

sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledonous plant that belongs to the Convolvulus, bindweed or morning glory family (biology), family, Convolvulaceae. Its large, starchy, sweet-tasting tuberous roots are used as a r ...

leaves, while the green pods have less antinutritional factors than the dried seeds.

Production and consumption

Most cowpeas are grown on the African continent, particularly in Nigeria and Niger, which account for 66% of world cowpea production.24/01/2015 FAO 2012 FAOSTAT Gateway
The Sahel region also contains other major producers such as

Burkina Faso Burkina Faso (, ; , ff, 𞤄𞤵𞤪𞤳𞤭𞤲𞤢 𞤊𞤢𞤧𞤮, italic=no) is a landlocked country in West Africa with an area of , bordered by Mali to the northwest, Niger to the northeast, Benin to the southeast, Togo and Ghana to the ...

Ghana Ghana (; tw, Gaana, ee, Gana), officially the Republic of Ghana, is a country in West Africa. It abuts the Gulf of Guinea and the Atlantic Ocean to the south, sharing borders with Ivory Coast in the west, Burkina Faso in the north, and To ...

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 � ...

, and

Mali Mali (; ), officially the Republic of Mali,, , ff, 𞤈𞤫𞤲𞥆𞤣𞤢𞥄𞤲𞤣𞤭 𞤃𞤢𞥄𞤤𞤭, Renndaandi Maali, italics=no, ar, جمهورية مالي, Jumhūriyyāt Mālī is a landlocked country in West Africa. Mali ...

. Niger is the main exporter of cowpeas and Nigeria the main importer. Exact figures for cowpea production are hard to come up with as it is not a major export crop. Estimating world cowpea production is rather difficult, as it is usually grown in a mixture with other crops, but according to a 1997 estimate, cowpeas were cultivated on and had a worldwide production of . While they play a key role in subsistence farming and livestock fodder, the cowpea is also seen as a major cash crop by Central and West African farmers, with an estimated 200 million people consuming cowpea on a daily basis. According to the

Food and Agriculture Organization of the United Nations The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...

, as of 2012, the average cowpea yield in Western Africa was an estimated , which is still 50% below the estimated potential production yield. In some tradition cropping methods, the yield can be as low as . Outside Africa, the major production areas are Asia,

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

, and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

is the world's second-leading producer of cowpea seed, accounting for 17% of annual cowpea production, although most is consumed within the country.

References

External links

Cowpea research at the International Institute of Tropical Agriculture (IITA)

Network for Genetic Improvement of Cowpea for All (NGICA)

Consensus Document on Compositional Considerations for New Varieties of COWPEA (Vigna unguiculata): Key Food and Feed Nutrients, Anti-nutrients and Other Constituents, OECD Series on the Safety of Novel Foods and Feeds No. 30
* Adam D. Steinbrenner, Maria Muñoz-Amatriaín, Antonio F. Chaparro, Jessica Montserrat Aguilar-Venegas, Sassoum Lo, Satohiro Okuda, Gaetan Glauser, Julien Dongiovanni, Da Shi, Marlo Hall, Daniel Crubaugh, Nicholas Holton, Cyril Zipfel, Ruben Abagyan, Ted C. J. Turlings, Timothy J. Close, Alisa Huffaker, and Eric A. Schmelz
A receptor-like protein mediates plant immune responses to herbivore-associated molecular patterns
In: PNAS. November 23, 2020. doi:10.1073/pnas.2018415117. See also: :* Carly Cassella
Saliva From Hungry Caterpillars Alerts Cowpea Plants to Turn on Their Defenses
On: science^alert. 5 December 2020 {{Authority control Edible legumes Flora of Nepal Nitrogen-fixing crops Vigna