Cowpea farming in Africa is done for the cowpeas seeds and also their leaves. The cowpeas are the easiest of the plants in the bean family to grow. They do well in the harshest of climates and require very little rainfall. Cowpeas are rarely grown under irrigation since they yield a lot of leaves when exposed to a lot of water but produce little grain. The rainfall required for the farming of cowpeas is about 200mm in the season of growth. Worth noting is that cowpeas are indigenous to Africa having been in the continent over 3000 years ago.
The cowpeas farming in Africa can be done in almost any type of soil. However for better yields, well-drained and fertile soils are ideal for the effective farming of the cowpeas. Land should be well prepared before planting and seeds planted directly to the fields should have spacing of between 30 to 40 cm. Depending on the fertility of the soil and the atmospheric temperatures. Intercropping can be done with maize, millet or sorghum.
When intercropped the spacing may be more than when monocropped. The cowpeas are seldom irrigated but are mostly grown using rain or residual moisture from harvested rice. Weeding should be done biweekly for the one and a half month period after planting since weeds are known to reduce the yield of the cowpeas by up to 60% and sometimes more especially if the crop is planted on the same plot in subsequent seasons, later however the cowpeas are known to suppress any infestation of weed. Cowpeas do not respond to fertilizer so none should be added. Manure or compost can be used for the much depleted soils.
The most common pests for the cowpeas farming in Africa include, aphis, beetles, and thrips. The aphis attacks the whole plant sucking the sap off it, the aphis also acts as a vector for viral diseases. The plant if young dies and for mature crops the yield is greatly reduced. This can be avoided by getting pest resistant varieties or by use of neem. Beetles feed on the flowers and leaves and inflict a lot of damage to the crop. The beetle menace is complicated to deal with since the larvae of the beetle provide protection against pests like the grasshopper. Adult beetles should be physically destroyed though protective clothing should be worn.
Thrips are the most dangerous pest of the cowpeas farming in Africa. They cause total crop failure the adults and nymphs of the thrips cause damage to the terminal buds. This leads to the crop not flowering and therefore not producing. The remedy to this is intercropping with sorghum or use of resistant varieties. The common diseases of the cowpeas include the mosaic disease affecting the leaves by forming mosaic shapes the crops fail to mature leading to crop failure. To deal with the disease, seed selection is important as well as crop rotation with non leguminous plants. Anthracnose is a significant cowpeas disease attacking the stems, leaves and even the pods leading to browning of the plant and death of the plant. The disease can be prevented by use of crop rotation with non leguminous plants, use of certified seeds and practicing field hygiene.
Leaves are harvested when tender at about 3 weeks after planting of the crop and weekly thereafter until harvest. Green pods are harvested about 13 days after flowering. The dry crop is usually very difficult to harvest as the pods shutter and scatter the grain.