Cowpea is one of the most ancient crops known to man. Its origin and subsequent domesticatio is associated with pearl millet and sorghum in Africa. It is now a broadly adapted and highly variable crop, cultivated around the world primarily for seed, but also as a vegetable (for leafy greens, green pods, fresh shelled green peas, and shelled dried peas), a cover crop and for fodder. Cowpea has a number of common names, including crowder pea, black-eyed pea and southern pea. It is known internationally as lubia, niebe, coupe or frijole. However, they are all the species Vigna unguiculata (L.) Walp., which in older references may be identified as Vigna sinensis (L.). The largest production is in Africa, with Nigeria and Niger predominating, but Brazil, Haiti, India, Myanmar, Sri Lanka, Australia, the U.S., Bosnia and Herzegovina all have significant production. Worldwide production of cowpeas is approximately 20 million acres.
In the U.S., the largest market class of cowpea harvested as dried seed is black-eyed pea and pink-eyed/purple hull southern pea. They are often cooked with water and canned or frozen. However, some cowpeas are harvested while the seed are high moisture, and sold fresh, typically referred to as southern peas. Southern peas are shelled green and the peas can be cooked fresh or frozen for later use, but there is also some consumption of the whole ‘pea pod’ as a fresh vegetable. The focus within this guide will be on production of the dried cowpea, which can be harvested with conventional grain combines.
Cowpea is considered more tolerant to drought than soybeans and better adapted to sandy soils. Many cowpea cultivars have a vining growth habit, but modern plant breeding has also led to more upright, bush-type cultivars. The vining type is preferred for forage or cover crop use, while the bush type is better suited for direct combining. There are cowpea breeding programs throughout the primary production areas, which include Arkansas, California, Texas and southeastern states. Yield information is available on the varieties released from these programs.
Total production of cowpeas for dry seed harvest in the U.S. is estimated at 60,000 to 80,000 acres. Cowpeas are grown on some farms in the southeast Missouri, where they are double cropped after wheat.
Plant Description
All cultivated cowpea varieties are considered warm season and adapted to heat and drought conditions. Cowpeas typically reach a canopy height of 30 to 36 inches in Missouri, although the more determinate bush types may reach only 24 inches. The seed pods are borne above the leaf axil, making the pods very visible. The seed pod is typically 3 to 6 inches long and has 6 to 13 seeds per pod. The seed weight per bushel is 60 pounds with about 3,000 to 4,000 seeds per pound.
The germination of the seed is rapid at soil temperatures above 65° F. The preferred varieties for Missouri (early types) will set pods in about 60 days and mature in 90 to 100 days with a June planting. Leaves will dry down but may not drop off completely. The relatively fast maturity of cowpeas allows their use as a double crop after wheat or canola in southern Missouri. They would probably mature too late for double cropping in northern Missouri.
Black-eyed peas
Utilization
Dried black-eyed peas and pink-eyed/purple hull peas are used for food products. The dried beans are frequently sold directly to the consumer after cleaning and bagging. Another common product is the canned or frozen product, which is cooked with water prior to canning or freezing. Various soups and bean mixes will incorporate this product as well. Cowpea is considered nutritious with a protein content of about 23%, fat content of 1.3%, fiber content of 1.8%, carbohydrate content of 67% and water content of 8-9%. As in most legumes, the amino acid profile complements cereal grains.
