Cowpea
Vigna unguiculata
Also known as: blackeyed peas, southern peas
Subtropical and tropical annual legume
Uses
- Nitrogen source (100-150 lb. N/ac)
- Biomass/organic matter source (Dry Matter: 2,500-4,500 lbs/ac/yr)
- Weed suppression
- Insectary plant
- Companion crop in orchards, vineyards, corn
- Drought tolerant
- Food, seed, forage, or hay crop
Plant Highlights
- EXCELLENT for providing erosion control, for suppressing weeds
- VERY GOOD for quick growth and establishment
- GOOD for increasing organic matter and improving soil structure, for animal grazing (production, nutritional quality & palatability)
- FAIR for taking up & storing excess N, for providing lasting residue.
Cultural Traits
- Excellent heat tolerance
- Very good drought tolerance
- Good shade tolerance
- Fair flood tolerance
- Excellent tolerance to low fertility
- pH range 5.5-6.5
Planting
- Planting depth: 1 - 11/2 inches
- Inoculant Type: cowpeas, lespedeza
Seeding Method
- Drilled: Seed at 30-90 lb./A
- Broadcast: Seed at 70-120 lb./A
Seed Cost: .50 $/lb
Seed Availability: Readily available
Cultivars
Cultivars commonly recommended by the Hawai`i Natural Resources Conservation Service include: 'Mississippi Pinkeye Purple Hull' which is reported to be root knot nematode resistant, burrowing nematode susceptible.
Mixes
with sorghum-sudangrass hybrid, buckwheat
Soil Improvements
- Good for loosening subsoil
- Good at releasing P and K
- Very good at loosening topsoil
Pest Control
- Poor for suppressing nematodes
- Poor for disease suppression
- Poor allelopathic properties
- Excellent weed suppression
- Very good for attracting beneficial insects
Management Attributes
- Poor trafficability
- Rapid establishment and growth ideal for short windows
Notes
- Cowpeas germinate quickly and are easy to establish. They thrive in hot moist climates.
- To control disease and nematode problems, cowpeas should be rotated with four to five years of crops that are not hosts.
- Once cowpeas form pods, they may attract stinkbugs. Flail mowing or incorporating cowpeas at pod set or plan crop rotations with resistant crops.
- Cowpeas survive drought well once established.
- Mowing stops vegetative growth but may not kill plants without shallow tilling.
- Cowpeas have extrafloral nectaries that attract beneficial insects such as wasps, honeybees, lady beetles, ants and soft-winged beetles.
Uses in the Pacific Region
No information is available in this database on this topic.
Uses in Hawai'i
The Hawai`i Natural Resources Conservation Service Technical Guide includes Cowpea (cv. 'Mississippi Pinkeye Purple Hull'). Their specification describes Cowpea as follows:
- Minimum broadcast seeding rates of 60 lbs. pure live seed/acre;
- pH range from 5.5-8.3;
- Inoculant group: cowpea;
- Approximate growing time 90 days;
- Approximate dry matter yield 2 tons/acre;
- Approximate N content 59 lbs./T dry matter;
- Optimum planting period year round at elevations from 0-1000 ft.;
- Optimum planting period spring/summer at elevations from 0-2000 ft.
For More information
UC Davis On-line Cover Crop Index
FAO Web Site
References
1998. Managing Cover Crops Profitably, 2nd ed. Sustainable Agriculture Network, National Agricultural Library, Beltsville, USA. pp. 212.
USDA Natural Resources Conservation Service, Hawai`i Field Office Technical Guide, Section IV, Code 340 "Cover and Green Manure Crop" May 1992. Pacific Islands Area Field Office Technical Guide (eFOTG) - East Area