Cowpea Farming In Kenya; A Complete Production Guide

Cowpea Vigna unguiculata (L.) Walp. is an important grain legume in the farming systems of Kenya since it is a major source of dietary protein and income for the people. The crop is usually grown at subsistence level as an intercrop with maize, sorghum, millet and/or cassava. It also play an important role in soil fertility improvement, suppression of weed, supply of vegetables and dry grain after maturity.

Cowpea Farming In Kenya

Cowpea rank second to beans in importance as vegetable protein food crops. It is consumed in the form of whole leaves or dried grains. The mean crude protein levels of leaves, grains and crop residues are 32 -34%, 23 – 35%, and 11 – 12% respectively. Cowpea is mainly grown as a green leafy vegetable in Western Kenya and for grain in the dry lands of Eastern, Coast and Nyanza regions. Cowpea grown as a vegetable requires rich soils and high rainfall.

In contrast, cowpea grown for grain requires low rainfall and high temperature. About 85% of total area under cowpea production in the eastern region of Kenya, is under intercropping systems with maize and or cassava.

Despite cowpea importance, its yields have remain low, or even declined. Low yields result from low soil fertility, poor agronomic practices, pest, diseases and poor postharvest management. Use improved and good crop management options could greatly reduce losses.

The grain is rich in protein, up to around 30% in some varieties. It also has micronutrients such as iron and zinc, which are necessary for healthy living. Women particularly value cowpea, which helps to bridge the “hunger months” prior to the main cereal harvest and also a source of cash to the rural and urban households.

Relative to other grain legumes and vegetable crops, cowpea possess multiple advantages for farmers. Cowpea is tolerant to drought and high temperatures as compared to other grain legumes. It is able to capture atmospheric nitrogen, providing symbiotic nitrogen fixation and hence improving soil fertility. Cowpea is cultivated with other crops as it tolerates shade and also covers the ground quickly, preventing erosion. It is thus a valuable component of farming systems in areas where soil fertility is limiting. It is intercropped with cereals in rotation.

Cowpea Varieties In Kenya

Cowpea productivity is constrained by lack of suitable high yielding varieties. However, existing cowpea varieties have been developed with different traits which are high yielding, early or medium maturing and have consumer-preferred traits such as large seeds, seed coat texture and colour.

A number of the varieties have resistance to some of the major diseases, pests, nematodes, and parasitic weeds. They are also well-adapted to sole or intercropping. Different varieties are recommended for different agro-ecological zones depending on the purpose of production i.e. grain, vegetable or dual. Some varieties have dererminate, indeterminate type morphology and others spreading or prostrate.

The seeds vary in shape, size and colors; viz white, purple, brown, black, cream or mottled.

The following are the common cowpea varieties grown in Kenya

“Machakos 66 (M66)”:

• A dual purpose bushy semi-spreading variety
• Flowers 55 – 60 days after germination
• Grown in higher altitude of 1,200 – 1,500 m.a.s.l.
• Tolerant to yellow mottle virus and scab and partly to aphid and thrips damage
• Moderately tolerant to Septoria Leaf Spot and Powdery Mildew

“Katumani 80 (K80)”:

• A dual purpose variety (vegetable & grain) with sprawling growth habit
• Flowers 50 days after emergence
• Tolerant to Aphids, Thrips, Pod borers and Leafhoppers
• Susceptible to Cowpea Yellow Mosaic Virus (CYMV)

“KVU 27-1”:

• A dual purpose variety with a semi-spreading habit
• Moderately tolerant to Aphids, Thrips, Pod borers and Leafhoppers
• Moderately resistant to fungal diseases and mosaic virus
• The 3 varieties above are for arid and semiarid areas

Other varieties grown in Kenya:

“Kenkunde”:

• A reddish brown pea which is drought tolerant but is bitter

Others:

• KVU 419, Kunde 1, KCP 022, Ngombe
• Local Varieties: these differ from one area to another and is defined by among other aspects, seed colour e.g.) white seed, black seed, growth habit or whether it’s drought tolerant or does well in wet season

Cowpea Seed Selection and Treatment

Use certified seed for successful production of cowpeas. The cost factor is slight when compared to probable yield losses, due to disease or poor stand. Low-quality seed causes poor and uneven stand, resulting in uneven maturity, harvesting problems and yield losses.

Seed Dressing

Selected seeds should be dressed with insecticides such as Thiram or Apronstar, Poncho, Cruiser and Marshall at the rate of 3g per kg of seed against pests and fungal diseases. Treated seed is unfit for human consumption and should be planted immediately. Insecticides should not be inhaled or allowed contact with the skin, hands should be washed with soap immediately after handling treated seeds. Therefore it is important to use personal protective equipment such as gloves, masks and goggles during soil dressing.

Site selection

Proper site selection is very important. Select a well-drained sandy loam soil for rainfed cowpea, and inland depressions or along the shores of a lake for a dry season crop using residual moisture. Cowpea does not tolerate excessively wet conditions or waterlogging and should not be grown on poorly drained soil.

To ensure high cowpeas production, one should select highly productive open land as it promotes maximum flowering and fruiting. One should avoid steeply sloping land, very sandy soil, areas with shallow surface soil and land that is near a swamp, planting on fields that had a leguminous crop previously should be avoided to escape diseases and break cycles of common pests.

Land preparation

Land preparation should be done early enough so that the field is free of weeds and ready for planting at the onset of rains. The seedbed should have fine soil to suppress weed growth and enhance moisture retention, easy germination and root penetration. In this regard the land must be ploughed and harrowed after clearing and all the trash removed.

The ground must be deep, level and firm because this ensures better surface contact between the seed and the soil, increasing the absorption of moisture. A level seedbed also facilitates planting to a uniform depth.

Clear the site of shrubs and stubble. Alternatively, spray the field with Glyphosate (Round-up) at the rate of 4 L/ha [about 2 1/3 peak liquid milk tins (157 ml) of chemical in a 15-L sprayer or 3 milk tins of chemical in a 20-L knapsack sprayer] and leave the field for at least 10 days for emerged weeds to be killed.

Land can also be prepared manually with the African hand-hoe. Soils should be cultivated deeply enough to ensure that no barrier (such as a hardpan) exists to penetration of the soil by the taproot. If using a tractor, plow and harrow the field to provide sufficient tilth for good root growth.

Well prepared land ensures good germination and reduces weed infestation. Make ridges thereafter, if desired. Where the soils are more fragile and prone to erosion, adopt minimum or zero tillage.

Ecological Requirements

Ecological factors considered include altitude, rainfall and soil/ambient temperature.

Altitude

The crop grows from sea level to an altitude of 1500 meters above sea level (masl). Above this altitude there is the problem of frost damage.

Rainfall

Cowpea is a warm weather crop that requires less rainfall as compared to most crops. The crop is mostly cultivated under rain-fed conditions but can also perform well in irrigated conditions. It requires a minimum of 200 to 500mm of rainfall during the growing season, distributed at planting to encourage vegetative growth and around flowering, moisture deficiency mainly affects vegetative growth. The most critical moisture requirement period is just prior to and during flowering when it affects pod setting and filling.

When grown under irrigation, over-watering may result to low soil temperatures which suppresses growth and soil borne diseases. Excessive rainfall during flowering causes flower drop and increased disease incidences. Dry weather is required during harvesting.

Soil type

Cowpeas are adapted to a wide range of soils from sandy soil to well-drained clay soils. It does better in lighter soils that favour good root development. Cowpea does not tolerate excessively wet condition and have low tolerance to waterlogging. It requires a soil pH that range between 5.6 to 6.5. Below pH 4.5, plant growth is impaired through limitation of development of the Rhizobium bacteria that are responsible for the nitrogen fixation.

Organic fertilizers

As a legume, the cowpea fixes its own nitrogen. Too much fertilizer will result into heavy vegetative growth and reduce grain production. Use of at least 2 tons/acre of well decomposed compost or farmyard manure is recommended especially in areas where soils are low in organic matter content. This is best applied under dry conditions and then mixed with the topsoil, about one week prior to planting.

Inorganic fertilizers

Cowpea requires more phosphorus (P) than nitrogen. About 60 kg/acre of (P₂O₅) is recommended for cowpea production to help the crop to nodulate well and fix its own nitrogen from the air. Phosphorus is critical to cowpea yield because it stimulates growth, initiate nodule formation as well as influence the efficiency of the rhizobium-legume symbiosis. The fertilizer should be thoroughly mixed with soil before placing the seed.

Temperature

The cowpea crop thrives in a warm climate at optimal temperatures of 20°C to 35°C. The maximum temperature during flowering should not exceed 30 °C. High temperatures during the flowering stage leads to dropping of flowers and a low pod set It can be grown under rainfed conditions as well as by using irrigation during the dry season. The optimal temperature range is between 28°C and 30°C. The crop is very sensitive to frost, and minimum temperatures should not go below 13°C.

Planting Cowpea In Kenya

Cowpeas should be planted at the onset of rains. For a good plant stand and high yields, seeds must be of high quality. For early maturing varieties, planting at the beginning of the rains is advised so that the sensitive stages of the crop avoid the peak activity of insect pests. Ideally, planting should be timely in relation to the maturity period of the variety, such that the crop is harvested during the dry weather.

Spacing for cowpea farming

Under sole cropping system, the recommended spacing for erect/semi-erect and spreading varieties is 60cm × 20cm and 50 cm x 75 cm respectively. Row planting is recommended so that the correct plant density may be established. When intercropping with cereals the recommended method is to have one cowpea row between the cereal rows at 20 cm within the row, two seeds per hill.

The soil texture and moisture content determine planting depth. Generally the seeds are placed 2.0 to 5 cm below the soil surface.

Cowpea Seed rate per acre

The amount of seed required depends on the variety, seed size, cropping system, and viability. Because of closer spacing more seeds of erect varieties are used compared with the spreading varieties. Similarly, fewer seeds are required when the cowpea is to be intercropped with other crops. The seed size also determines the quantity of seed to be used. Larger seeds implies more seed quantity is required for use. Generally the recommended seed rate is 12-25kg/acre.

Cowpea Yield Per Acre

The average cowpea yield per acre in Kenya is 800-1800 kg. This means that a one-acre field of cowpeas can produce anywhere from 1,198 to 2,286 Kgs of cowpeas. The actual yield will vary depending on a number of factors, including the variety of cowpea planted, the soil fertility, the amount of rainfall, and the level of pest and disease control.

Profitability of Cowpeas Per Acre In Kenya

Expected Expenses:

1. Seeds: Cost of purchasing cowpea seeds.
2. Land Preparation: Expenses related to plowing, tilling, and preparing the land.
3. Fertilizers: Cost of fertilizers for soil enrichment.
4. Pesticides and Herbicides: Expenses for controlling pests and weeds.
5. Labor: Wages for labor involved in planting, maintenance, and harvesting.
6. Irrigation/Watering: Cost of irrigation systems or water for watering the crop.
7. Miscellaneous: Other miscellaneous expenses.

Let’s assume hypothetical values for these expenses:

1. Seeds: 10,000 KSHS
2. Land Preparation: 20,000 KSHS
3. Fertilizers: 15,000 KSHS
4. Pesticides and Herbicides: 8,000 KSHS
5. Labor: 30,000 KSHS
6. Irrigation/Watering: 5,000 KSHS
7. Miscellaneous: 7,000 KSHS

Total Expected Expenses = Sum of all expenses Total Expected Expenses = 10,000 + 20,000 + 15,000 + 8,000 + 30,000 + 5,000 + 7,000 Total Expected Expenses = 95,000 KSHS

Now, let’s calculate the profits for both scenarios:

Low Yield Scenario:

• Production: 800 kg
• Selling Price per kg: Ranges between 160 KSHS to 250 KSHS

Potential Profit (Low Selling Price) = (800 kg * Low Selling Price) – Total Expected Expenses

Potential Profit (High Selling Price) = (800 kg * High Selling Price) – Total Expected Expenses

High Yield Scenario:

• Production: 1800 kg
• Selling Price per kg: Ranges between 160 KSHS to 250 KSHS

Potential Profit (Low Selling Price) = (1800 kg * Low Selling Price) – Total Expected Expenses

Potential Profit (High Selling Price) = (1800 kg * High Selling Price) – Total Expected Expenses

Remember, the selling price ranges given earlier were 160 KSHS to 250 KSHS per kg.

Please substitute the values for the selling price from those ranges and perform the calculations to determine the potential profits for each scenario. The results will give you a clearer understanding of the profitability of cowpea production based on different yield and selling price scenarios.

Crop rotation

This practice is recommended to avoid pest and disease build up. Rotation is mainly done with cassava, maize, sorghum or any other non-leguminous crop.

Common weeds and their Management

Weeds cause losses in cowpea production through nutrient and moisture competition. Losses of up to 100% having been experienced where weeds have been left uncontrolled. Major weeds affecting cowpea include; black jack (Bidens pilosa), pig weed (amaranth) Couch grasses clover, Wandering Jew, sow thistle star grass and devils thorn. Perennial weeds with vigorous growth may choke the cowpea plants hence lowering yields. The weeds reproduce and spread mostly by means of seeds.

Others reproduce by means of rhizomes and stolons.

Cowpea should be kept free from weeds in all stages of growth. Timely weeding is absolutely essential. Thorough weeding which reduces the risk of weed spreading and reduces the pest and disease infestation at the early stages is achieved by a first weeding two weeks after emergence followed by a second weeding three weeks later (just before flowering) in monocropping. In  intercropping, one weeding three weeks after planting may be sufficient except in high rainfall areas where a second selective weeding three weeks later may be necessary.

Care should be taken to avoid damaging the shallow roots especially during the first weeding. Cultivation during flowering time is discouraged, to avoid flower shedding and when the field is wet to avoid spread of diseases and soil compaction.

Where possible herbicides may be used to control weeds. The choice of herbicide depends on the predominant weed species and time of application. Pre-emergence herbicides are used to control weeds before they emerge while post-emergence herbicides are used to control weed after they emerge. If pre-emergence herbicide is applied, one manual weeding may be done depending on population.

Controlling Pests and Diseases of cowpea

Diseases and pests contribute to low productivity in cowpea. Incidences and severity vary between seasons because of environmental conditions and management practices. Integrated disease and pest management and using environmentally safe sttrategies is recommended. The cowpea pests and diseases and their control measures are discussed in the following section.

Pests and diseases are major constraints in cowpea production in Kenya. Under different conditions, losses of up to 50% have been reported due to anthracnose. Accuracy in pest and disease identification are important for proper management. It is therefore necessary to build the capacity of extension officers and growers in pest and disease management in order to minimize losses. Crop protection aims at providing the necessary information to stakeholders to minimize losses due to pests.

Integrated pest management (IPM) is the use of a combination of various strategies for management of pests and diseases. These practices use plant resistance, physical, cultural, biological, chemical and exclusion options to maintain pest populations below economic injury levels, with minimal impacts on non-target organisms, food safety, terrestrial and aquatic environments.

In IPM, scouting and monitoring of pests and establishment of action thresholds to guide application of management strategies are very important. Indications suggest that IPM in Kenya is not widely practiced by smallholders in many regions and therefore needs to be promoted to limit use of pesticides and enhance food and environmental safety.

Harvesting

Dry cowpea should be harvested when the plants turn yellow to light brown and the leaves start to fall off by hand picking the pods since they mature unevenly.

When the entire plant is physiologically mature the plant is uprooted. Early-maturing and erect varieties, the pods mature and dry evenly, hence harvesting can be done once by uprooting the entire plant or hand picking. For indeterminate and prostrate varieties, the pods mature and dry unevenly hence the pods should hand-picked as they mature and dry.

Harvesting should be prompt, as delay in harvesting encourages weevil infestation in the field and seed shattering. If the condition is humid the quality of grains may deteriorate due to moulds.

After harvest, pods should be sun-dried immediately, and then threshed. Before storage, clean grains and separate them from chaff or haulms through winnowing. Only well-dried and properly cleaned grains should be stored. It is important to dry cowpea before storage to reduce the moisture content of grains in order to avoid getting mouldy. Dry the pods for one to two weeks and well-dried cowpea grain should have less than 10% moisture content. Such grains should make a cracking sound when crushed between the teeth.

NOTES

The main points to remember in green grams production are:

• Do timely land preparation and timely planting to take advantage of rain and control diseases.
• Plant clean certified seeds to prevent seed-borne diseases.
• Plant clean seeds for high germination, uniform growth and maturity.
• Keep proper population for optimal yield and reduced disease incidence.
• Maintain a weed free field to reduce competition and disease build up.
• Prevent and control of pest and diseases in all stages to minimize loss (quantity and quality).
• Scout once to twice a week for pests and diseases for timely management.
• Uproot and destroy severely infected plants by burning.
• Timely harvesting and proper post-harvest handling for long shelf life.
• Ensure timely harvesting and proper post-harvest handling for long shelf life.

FAQs

• How many days does it take to grow cowpeas?

It takes about 80-120 days for cowpeas to mature and be ready for harvest.

• How much do cowpeas produce per acre?

The yield of cowpeas per acre can vary depending on the variety, the soil fertility, and the amount of rainfall. However, a typical yield is 800-1800 kg per acre.

• Is cowpeas farming profitable in Kenya?

Yes, cowpeas farming can be profitable in Kenya. The demand for cowpeas is high, and the prices are relatively stable. However, the profitability of cowpeas farming can vary depending on the yield and the cost of production.

• How much is a kilo of cowpeas?

The price of cowpeas per kilo can vary depending on the season, the location, and the quality of the beans. However, a typical price is around 160 KSH per kilo.

• What is the best fertilizer for cowpeas?

The best fertilizer for cowpeas will depend on the soil fertility and the needs of the crop. However, a balanced fertilizer, such as 10-10-10, is a good starting point.

• How long do cowpeas take to germinate?

Cowpeas take about 5-7 days to germinate.

• What is the spacing for cowpeas?

The spacing for cowpeas will depend on the variety, but a typical spacing is 30 cm between plants and 60 cm between rows.

• How far apart do you plant cowpeas?

The spacing for cowpeas is typically 30 cm between plants and 60 cm between rows.

• What is the lifespan of a cowpea?

The lifespan of a cowpea plant is about 6 months.

• What is the best time for planting cowpea?

The best time for planting cowpeas in Kenya is during the rainy season, which is usually from March to May.

• What is the maturity age of cowpea?

The maturity age of cowpeas varies depending on the variety, but it is typically about 80-120 days.

• Is cowpeas profitable?

Yes, cowpeas can be a profitable crop to grow in Kenya. The demand for cowpeas is high, and the prices are relatively stable. However, the profitability of cowpeas farming can vary depending on the yield and the cost of production.

• How do you intercrop cowpea and maize?

Cowpeas and maize can be intercropped by planting them together in the same field. This can help to improve the productivity of both crops. The best way to intercrop cowpeas and maize will depend on the specific varieties of each crop that you are planting.

• How many bags of beans can 1 acre produce in Kenya?

The number of bags of beans that 1 acre can produce in Kenya varies depending on the variety, the soil fertility, and the amount of rainfall. However, a typical yield is 20-30 bags per acre.

• Which is the most profitable crop to grow in Kenya?

The most profitable crop to grow in Kenya will vary depending on the location, the soil conditions, and the market demand. However, some of the most profitable crops in Kenya include maize, beans, potatoes, and tomatoes.

• How much is a 90kg bag of beans in Kenya?

The price of a 90kg bag of beans in Kenya can vary depending on the season, the location, and the quality of the beans. However, a typical price is around 2,000 KSH per bag.

• Is DAP fertilizer good for beans?

DAP fertilizer is a good source of nitrogen and phosphorus, which are essential nutrients for beans. However, it is important to apply DAP fertilizer at the right time and in the right amount to avoid over-fertilizing the crop.

• Which fertilizer to use when planting beans?

The best fertilizer to use when planting beans will depend on the soil fertility and the needs of the crop. However, a balanced fertilizer, such as 10-10-10, is a good starting point.

• What is the spacing for beans in Kenya?

The spacing for beans in Kenya will vary depending on the variety, but a typical spacing is 30 cm between plants and 60 cm between rows.