Best practices for growing pigeon peas

Pigeon peas grow in a variety of agro-ecological zones and are well adapted to semi-arid climate conditions.
In sub-Saharan Africa it is widely grown in Kenya, Uganda, Tanzania, Malawi and Mozambique.

As droughts become common and dry lands expand due to climate change, pigeon peas will continue becoming important for managing food security and nutritional situation in Africa.

Unlike other legumes, pigeon pea is one of the few crop species that can utilise iron bound efficiently making it capable of producing appreciable yields even under soil PH limiting conditions which are widespread in in Africa.

Pigeon pea is a perennial shrub that is commonly grown as an annual crop. It has very slow initial development after planting.
With a deep taproot, pigeon peas are able to take up nutrients and water from lower subsoil layers. Therefore in crop mixes they hardly compete with the companion crops. This crop grows and yields well under conditions of low rainfall and poor soil.

Pigeon pea is well balanced nutritionally and an excellent source of protein and vitamin A. It is eaten as a vegetable immature pods or green pea or as dried cooked grain.

Against this background Emma Mbeyagala, the officer in charge of breeding the crop at the National Semi Arid Resources Research Institute (NaSARRI) gives excerpts of good agronomy practices farmers can embrace to get good yield.

Soil
Optimum temperatures for pigeon pea cultivation range from 18 to 38 degrees Celsius and it does not tolerate water logged soils.
Rainfall optimum is approximately 600-1000 mm per year. It is sensitive to high salinity and to water logging. It flowers well where rainfall is 1500 to 2000 mm.
On deep, well - structured soil it will grow where rainfall is 250 to 370 mm and drained soils of reasonable water holding capacity and with pH 5-7 are favourable for its growth.

Varieties
The commonly grown varieties by farmers in Uganda include Apio Elina with maturity rate of 6 - 9 months and grain yield of 250 - 500 kilogrammes per hectare, Adyang which matures between 6 - 9 months and the yield is 250 - 450 kilogrammes per hectare and ICPL 87091 which matures in 97 - 104 days with yield: rate of 1.99 tonnes per hectare.
Others are ICPL 87101 which matures in 93 - 102 days with yield capacity of 2.2 tonnes per hectare. ICPL 90029 varieties mature between 92 and 104 days with yield rate of 1.6 - 2.5 tonnes per hectare.

The newly released varieties include Sepi I which matures in 130 – 150 days with yield rate of 1,200 kilogrammes per hectare and Sepi II which yields in 120 days at a yield rate of 1,000 kilogrammes per hectare.

Propagation is by seed, stem cuttings rarely succeed. Pigeon pea varieties differ not only in form of seeds, colour and taste but also in growth habit, time of flowering and susceptibility towards pests and diseases. The seed rate is between 20 to 25 kilogrammes per hectare

Land preparation
The crop thrives best in seedbeds prepared by deep ploughing and cultivations to reduce weeds.
Seeds should be sown in rows with spacing of 75cm by 25 cm. In dry areas and especially in coarse textured infertile soils, farmers use wide spacing between plants to limit competition.

Plants are fairly slow to start and weed control for the first two months is important in crop establishment. Once plants are established they grow vigorously.

Weeding
Weeds must be controlled to facilitate slow initial growth. Wind may bend the plants but staking is not practiced. It is important to weed the farm 2 – 3 times during the first two months from planting.
In eastern Africa, the crop is cultivated on marginal lands by resource poor farmers who traditionally grow landraces. Inputs such as fertilisers, irrigation and pesticides are hardly used.
Intercropping
It performs well with two rows of cereals such as sorghum, millets including cotton or groundnut.

After harvest of the intercrop, long-duration pigeon pea continues to grow and protects the soil.

It is regarded as a good plant for restoration of fertility and is used in a rotation with crops such as maize-groundnut and tobacco.
One of the advantages of pigeon pea is the increased growth of the grass inter-planted with it.

Farmers usually sow it in alternate rows with sesame or African finger millet and sometimes maize. However, due to its high demand, there is a tendency to move away from traditional intercropping to monocropping in a bid to grow it on large scale.

Pests
Surveys in Kenya, Malawi, Tanzania and Uganda have shown that the most destructive pests of pigeon pea pods and seeds in the region are pod sucking bugs and seed boring caterpillars and pod flies.

Others are root rot nematodes where affected plants are normally stunted and eventually wilt and dry off. The most characteristic symptom is formation of root knots and these can be seen with the naked eye.

Farmers are advised to plant resistant varieties and plant in fields with no previous record of nematode infestation as well as rotate with cereals.

Diseases
The commons diseases are Fusarium wilt which may cause wilting at flowering stage and crop rotation and planting of resistant varieties is advisable.
Another disease is Cercoospora leaf spot which causes narcotic sports of the leaf which leads to abortion of flowering.
There is Macrophomins stem canker fungal infection which affects the stems of the plant.

Another is powdery mildew which causes fungal growth affecting all parts of the plant. The solution is to plant clean seeds and follow the right agronomy practices such as early weeding.

Harvesting and storage
The crop is usually cut near the ground when pods are mature or mature pods are picked individually.

Green pods are picked over a long period in home gardens or hedge crops. After harvest the stems are cut back to facilitate re-growth and a second crop is harvested in the subsequent season.

The pods are usually threshed by hand and seed is cleaned. Clean beans prevent insect attack which can be considerable.
Threshing should be done on clean ground and bags for storage must be new. If possible triple air bags can be used to avoid weevil penetration
In case of weevil infiltration farmers are advised to use pesticides such as actellic and insecticide dust.