Cowpea (Vigna unguiculata)
Plant Characteristics: Annual viney plant with three large leaflets, white flower and curved pots.
Establishment: Very tolerant to drought, shade, and low fertility and acid soils. It will adapt well to the southern part of the state. Cowpea can be broadcast at rates of 100 to 120 lb/ac between April 1 and July 31 and cover with light disking or drilled at rates of 30 to 40 lbs/ac to a depth of 1-1.5 inches. For good germination, soil temperature should be above 70°F.
Several label herbicides such as uthority, Dual, Poast, Pursuit, and sodium chlorate can be used in cowpeas. Pursuit provides some broadleaf control, while all the products control grass weeds. Very similar to soybean and can affected by diseases such as rust and leafspots.
Possible diseases are fusarium wilt, bacterial canker, southern stem blight, cowpea mosaic virus (and several other less prominent viruses), cercospora leaf spot, rust and powdery mildew. The following fungicides* are registered for cowpeas—Maxim, Maxim-XL, Mefenoxam, Metalaxyl, Mycostop, Ridomil-Gold and Thiram.
Insects such as grasshopers, curculio weevil, Southern cornstalk borer, root-knot, and army worms can be a major problem. The following insecticides* are registered for cowpeas—Adios, Azadirachtin, Bacillus thuringiensis, Capture, Di-Syston, Gaucho, Insecticidal soap, Lorsban, Methaldehyde, Methomyl, Pyrellin, Pyrethrin, Sevin, Success, Telone, and Trilogy.
Fertilization: N is not required. Cowpea performs best on well-drained sandy loams or sandy soils where soil pH is in the range of 5.5 to 6.5. Excess nitrogen (N) promotes lush vegetative growth and delays maturity. A starter N rate of around 27 lb/acre is recommended for early plant development on low-N soils. A soil test is the best way to determine soil nutrient levels. At least 27 lb P/acre and 40 lb K/acre are recommended on soils of medium fertility but individual soils will vary in fertilizer requirements. Band fertilizer 3 to 4 inches deep and 2 to 3 inches away from the seed, or broadcast and disc in all fertilizer, including nitrogen, before planting.
Grazing/Hay Management: Yields ranging from 2 to 3.5 tons/ac. Cowpea can also be used for the production of high quality hay or silage, when mixed with crops such as corn or sorghum, or it can be used for rotational grazing.
Forage Quality: Good. Protein (20 and 25%), NDF (35 to 38%), ADF (25 to 28%), Lignin (5 to 6.8%), IVDMD (69 to 73%).
Varieties/Cultivars: Mississippi Pinkeye Purple Hull is a common variety and resistant to root-knot nematode and susceptible to burrowing nematodes. Others include Colossus, Freezegreen, and Alabama Giant Blackeye.