COWPEA FARMING
Cowpea (Vigna unguiculata) is an annual leguminous crop which is grown for its seeds and leaves, and its residues can used as livestock fodder. It can withstand drought, short growing period and its multi-purpose use makes it an attractive alternative for farmers in marginal, drought-prone areas with low rainfall.
The crop is also an important component in crop rotation because it has the ability to restore soil fertility. Besides, early maturing varieties provide food sooner than any other crops.
The main cowpea growing areas in Kenya are Kitui, Kisii, Migori, Kakamega, Bungoma, Machakos, Makueni, Kwale, Kilifi and Tharaka Nithi.
Nutritional & health benefits
- Rich source of dietary fiber and have been known to ease stomach conditions such as diarrhea and constipation.
- Rich in vitamin B and riboflavin
- Rich in magnesium and tryptophan which are essential in relaxing and calming the body. Magnesium also helps the body with the metabolism of carbohydrates therefore helping to balance the sugar levels, a way of managing some diseases like diabetes.
- It provides good amounts of iron which helps the body revive its red blood cell count and negate anemia.
- Low in calories and cholesterol, which is imperative for healthy weight loss.
- Rich in vitamin C, a strong antioxidant which helps in keeping the effects of free radicals, which are the cause of cancer and other chronic diseases.
- Improves bone health because it is rich in calcium and other minerals like iron, manganese and magnesium.
- Has lysine which prevents/ reduces cold sores and speeds up the healing process.
Ecological requirements
Altitude; The crop can be grown in areas of altitudes of 0-2000metres above sea level, depending on the variety.
Rainfall; Cowpeas are relatively drought tolerant and can give reasonable yields with minimal annual rainfall of between 300-700mm. Too much rain or long dry spells are reduce yields. Excessive rainfall during flowering causes flower abortion while dry weather conditions are important during harvesting.
Temperature; cowpeas perform best in warm conditions. An optimum temperature of between 20-35°C is fit for their growth. Extreme temperatures affect crop growth and development.
Soils; cowpeas can be grown on a wide range of soils. However, well drained fertile soils with an optimum PH of 5.5-6.5 promote better production.
Varieties
Cowpea varieties grown in Kenya include;
- Katumani 80 (K80)
- KVU 27-1, 419
- Kunde 1
- MTW 63, 610
- Machakos 66 (M66)
- Kitui black eye
- Other local varieties
Seed selection
The choice of a variety depends on the agro-ecological zone. For instance; some improved varieties like Katumani 80 and Kitui black eye are suitable for dry areas. Other factors to consider include the maturity period, resistance to pests and diseases and market preference, like colour of grains, among others.
Seed rate
Approximately 8-10kg of seeds is needed for a one-acre piece of land.
Yield
The yield potential varies from one variety to another and is also affected by the general crop maintenance and the ecological conditions. However, under good maintenance, the yield range from 800-1800kg per acre.
Propagation
Cowpea is directly grown from seed, and depending on the purpose for production, it can be grown as a sole crop or intercrop with other crops like cereals, e.g. maize.
Land preparation & planting
Land preparation should be done early to allow for weeds to dry and decompose before planting.
Planting should be done at the onset of the rains if production is rain fed. Delayed sowing may cause crop failure or reduced yield.
Procedure
- Spray weeds with CATAPULT® 480SL 200ml/20L.This kills both the broadleaf and grass weeds.
- Plough and prepare the land into a fine tilth.
- Mix soil with manure and DAP. For efficient and improved nutrient uptake as well as stabilizing soil pH, mix 1kg HUMIPOWER® with 50kg DAP and /or 1 ton of manure.
- Sow the seeds at a spacing of 6 inches apart and 24 inches between the rows, about 3-4cm deep.
- Cover seeds with loose soil.
Tips!
- Use certified seeds.
- Germination occurs within 4-10 days.
Weeding
Weeds compete with the crop for nutrients, moisture, space and sunlight and also harbour pests and diseases. In order to reduce or avoid the losses attributed to weed infestation, cowpea garden should be kept weed free. Weeding should however be minimized at flowering and fruiting stage in order to prevent disturbance to the crop.
Fertilizer application
Fertilizer application in cowpea production depends on soil fertility, and soil testing is recommended in order to determine soil nutrient levels.
During planting, application of DAP, which should be thoroughly mixed with the soil before planting helps the crop with root development. Other phosphatic fertilizers like TSP can be used. A week after germination, the young plants should be sprayed with LAVENDER SUPER STARTER® 20ml/20L or GOLDCHANCE SUPER START® 50g/20L which promote early crop establishment besides other benefits.
CAN is preferred for top dressing. The crop can also be sprayed with GOLDCHANCE SUPER GROWTH® 50g/20L or LAVENDER SUPER GROWTH & VEGETATIVE® 20ml/20L which promotes rapid vegetative growth. However, cowpea does not require too much nitrogen fertilizer because it fixes its own nitrogen from the air using the nodules in its roots. Application of excess nitrogenous fertilizers promotes lush vegetative growth, delays maturity, may reduce seed yield and may suppress nitrogen fixation.
As the crop begins flowering and setting pods, spraying it with GOLDCHANCE SUPER FLOWERS & FRUITS® 50g/20L or DIMIPHITE® 20ml/20L or GOLDCHANCE MULTISUPER K® 50g/20L or LAVENDER SUPER FLOWERS & FRUITS® 20ml/20L promotes production of quality pods and application of VITABOR GOLD® 30ml/20l also prevents flower abortion.
Tips!
- All basal fertilizers should be mixed with HUMIPOWER® at a rate of 1kg of HUMIPOWER® into 50Kg of fertilizer.
- OPTIMIZER® is an organic bio-stimulant which is essential for plant growth and stress management. It can be applied at all or any growth and development phase of the crop
Intercropping
Cowpeas can be intercropped with other crops including maize or sorghum and because it is a leguminous plant it helps in fixing nitrogen in the soil, thus improving soil fertility, thereby enhancing yields.
Maturity & harvesting
Cowpea can be harvested at different stages of maturity, i.e. leaves, green snaps, green-mature, and dry and depending on the variety and climatic conditions, cowpeas may take 60- 120days to mature their seeds.
Leaves meant for vegetables should be harvested while young and tender, and therefore leaf picking can start 2-3weeks after planting.
Pods can be harvested green or dry. Green pods are hand-picked while still tender, about 12-16days after flowering.
Matured, dried pods should be harvested promptly. Delayed harvesting encourages infestation with weevils, seed shattering and in humid weather the grains may deteriorate.
The entire plants can also be pulled especially if most of the pods are mature.
Threshing
The harvested pods should be dried for about 2-3 days, threshed and winnowed, ready for consumption or storage. Drying is important to reduce moisture content of grains significantly before storage in order to avoid seed getting moldy.
The pods can be manually threshed by beating the dried pods using a stick. Since the seeds can easily break/get damaged, threshing should be done lightly, aiming at just breaking open the If the quantity is not much, the pods can also be broken by fingers to remove the seeds.
Sorting & grading
Sorting is done to remove defective/shriveled and broken grains, stones, waste and infected seeds from healthy ones. Grading can be done considering factors like size, colour, and the general quality of the grains.
Packaging & storage
Usually, the dry cowpeas are stored in treated gunny or PICS bags which help to prevent major damages caused by storage pests. It is advisable to incorporate the seeds with an insecticide, e.g. Actellic super to prevent damages while in the store by pests. Storage bags should be placed on pallets, not directly on the floor.
For small amounts of seed, storage in wood ash is effective. The ash should be mixed thoroughly with the seeds.
Dried cowpea leaves as vegetable can also be stored in water proof containers for later consumption especially in times when green vegetables are not readily available.
Major pests & diseases
Pests
Aphids; they suck sap on leaves, stems, petioles, flowers and pods. Heavy infestation causes death of young seedlings, stunted growth and delayed flowering, especially on the older plants. They secrete honeydew as they feed which encourages the formation of sooty molds and are vectors of viral diseases, e.g. cowpea mosaic
Spray KINGCODE ELITE® 50EC 10ml/20L or PENTAGON® 50EC 10ml/20L or LEXUS® 247SC 8ml/20L
Spray JAMBO CLEAN® 100ml/20L to get rid of the sooty mold.
Bugs; these are sap sucking pest. The adults and nymphs attack young and tender pods causing their shriveling and eventual rotting. Seeds set malformed and lose viability.
Spray EMERALD® 200SL 10ml/20L or LOYALTY® 700WDG 5g/20L or PRESENTO® 200SP 5g/20L
African bollworm; this is a caterpillar which feeds on the crop, causing extensive damages on leaves, stems and pods. It feeds on seeds with its head inside the pod while the rest of the body remains outside.
Spray KINGCODE ELITE® 50EC 10ml/20L or BACIGUARD® 16WD 15g/20L or SINOPHATE® 750SP 20g/20L
Flower beetles; these cause serious damages to the crop by feeding on the flowers, i.e., the petals, pollen, etc. this reduces pod set.
Spray KINGCODE ELITE® 50EC 10ml/20L or PRESENTO® 200SP 5g/20L or SINOPHATE® 750SP 20g/20L
Pod borer; the caterpillars mostly feed on flowers and newly formed pods causing serious damages to the crop. Terminal shoots and leaves are also attacked.
Spray BACIGUARD® 16WD 15g/20L or KINGCODE ELITE® 50EC 10ml/20L or SINOPHATE® 750SP 20g/20L
Root knot nematodes; infestation leads to development of small galls or swellings on roots. These swellings should not be confused with the naturally occurring root nodules. The affected plant becomes stunted and dies eventually.
Drench soil with ALONZE® 50EC 10ml/20L or mix 1kg HUMIPOWER® with 50kg of basal fertilizer whenever applying.
Thrips; they cause major damages on flowers and flower buds. The attacked flower buds turn brown and die eventually while the flowers become distorted, discoloured and malformed, eventually falling off. Infected pods are also malformed.
Spray ALONZE® 50EC 5ml/20L or PROFILE® 440EC 30ml/20L or DEFENDER® 25EW 40ml/20L
Whiteflies; these are white insects which suck plant sap and secrete honeydew as they feed which facilitates the development of sooty mold. Attacked leaves curl, become distorted and drop.
Spray TAURUS® 500SP 10g/20L or LEXUS® 247SC 8ml/20L or PROFILE® 440EC 30ml/20L
Spray JAMBO CLEAN® 100ml/20L to clean the sooty mold
Bean flies; the larvae tunnel through the main stem and feed, causing significant damages. In severe cases of infestations, Seedling may die, leaves of the older plants turn yellow and become stunted while stems get thicker than normal and crocked.
Do seed dressing with SHIELD® 600FS 3ml/Kg
Drench soil with EMERALD® 200SL 20ml/20L or PROFILE® 440EC 60ml/20L
Spray KINGCODE ELITE® 50EC 10ml/20L or LEXUS® 247SC 8ml/20L to control the adults.
Foliage beetles; they feed on the leaves causing defoliation, especially on the young plants.
Spray SINOPHATE® 750SP 20g/20L or LEXUS® 247SC 8ml/20L or KINGCODE ELITE® 50EC 10ml/20L
Cowpea bruchids; these are storage pests, also known as cowpea weevils. Infestation begins in the field and continues in storage where the insect population grows until the grains are completely damaged. Adult females lay eggs on the grains, which hatch within 7 days, and the larvae, which are legless, white or creamy yellow and cylindrical with fleshy and wrinkled bodies bore into the grains from where they feed on the grain content and develop into pupae in 4 weeks’ time. The adults exit the grains leaving small round holes. Damage caused by bruchids lead to loss of nutritional and viability of the produce as well as weight loss.
To control these pests, ensure that the grains are well dried and apply insecticides like Actellic dust.
Diseases
Damping off; infection causes seed rot before emergence from soil and the young seedling may die on infection, if disease is not controlled in time. This is favored by cool and wet soil conditions.
Drench soil with PYRAMID®700WP 100g/20L
Spray crop with GEARLOCK TURBO® 250WP 25g/20L
Anthracnose; this is a major disease of the cowpeas. Affected plant parts show dark brow lesions which are sunken. On pods, the lesions are covered with pinkish fungal spore mass under wet conditions. Severely infected plants die.
Spray RANSOM® 600WP 15g/20L or ABSOLUTE® 375SC 10ml/20L or DUCASSE® 250EW 20ml/20L
Rust; small reddish brown pustules develop on both sides of the leaf surfaces. Heavy infections cause leaf damage and defoliation.
Spray MILESTONE® 250SC 10ml/20L or RANSOM® 600WP 15g/20L or DUCASSE® 250EW 20ml/20L
Powdery mildew; diseased leaves, pods and stems develop light greyish powdery growth which can be easily rubbed off. Heavy infection causes chlorosis and defoliation.
Spray RANSON® 600WP 15g/20L or DOMAIN® 250EC 10ml/20L or CHARIOT® 500SC 20ml/20L
Cowpea mosaic; this is a viral disease which leads to formation of irregular dark green and light mosaic patterns on the leaves. These patterns are best seen on the young leaves. The crop becomes stunted and produced malformed pods. Infection at early growth stages inhibits pod development. The virus is transmitted by aphids.
Control vectors (aphids) by spraying LEXUS® 247SC 8ml/20L or KINGCODE ELITE® 50EC 10ml/20L or PENTAGON® 50EC 10ml/20L
Cercospora leaf spots; the spots are usually yellowish or brownish or with yellow halos and usually develop on the lower leaves first. Severe leaf spotting leads to defoliation.
Spray CHARIOT® 500SC 20ml/20L or RANSON® 600WP 15g/20L or DUCASSE® 250EW 20ml/20L
Remarks!
- In all foliar sprays, mix the chemical with INTEGRA 3ml/20L, which is a sticker, spreader and penetrant which increases the efficacy of the product.
- Post-harvest interval (PHI) and re-entry interval (REI) for all the applied chemicals should be observed.
- Use CADILAC® 800WP 50g/20L, which is a preventative fungicide against diseases including anthracnose and leaf spots.
- Harvesting can be carried out manually (hand harvesting) or by using a combine harvester in the case of large-scale production.
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