Agriculture

How To Benefit From Beans Farming in Kenya

Common bean (Phaseolus vulgaris L.) is the world’s most important legume for human consumption, according to Katungi et al 2010. Beans are a source of proteins which makes the Kenyan population depend highly on them. The market for beans is overwhelming, and depending on the quality and type of beans, the prices per 90kg bag of beans range between Sh7,000 and Sh12,000. The price is dynamic and influenced by seasons and varieties. Some varieties which are not grown by many farmers can fetch a higher price due to the difference in demand and supply.

 

Improved beans

 

There are numerous bean varieties. Between 2008 and 2018 around 33 new varieties were released through research organisations like Kenya Agriculture and Livestock Research Organisation (Kalro), Egerton University and Kenya Seed Company.

A bean researcher from Kalro David Karanja, says the new varieties are improved beans that perform better with the changes in climate, are resilient and contain trace nutrients like zinc, which is important for human growth and body condition.

“How many of these new varieties are known by change agents and farmers?” Mr Karanja poses. His question indicates that there is a great need to educate farmers on the new varieties for them to adopt climate smart and resilient agriculture. Some of the 33 new bean varieties include Angaza, Faida and Nyota.

 

Bean consumption behavior

 

Bean consumption behaviour also varies from place to place. Some communities consume the leaves as vegetables, others eat green beans like in the case of French and runner beans and the most common is the dry grain. The bean left over stover/stalks is also an excellent fodder for livestock and some communities burn it to make food additives called munyu by the Luhya community.

 

Bean Agronomy

It is caused by a fungus which attacks the leaves, stems and pods of bean plants. Rust spots have red-brown powdery substance. If not controlled in good time, excessive infection eventually leads to death of plant or plant parts, causing huge losses. Plant resistant varieties. Rotate with non-host plants like cereals.

 

Maintain field hygiene and if infected, spray fungicides alternating active ingredient (with sticker).

 

Powdery mildew

 

Symptoms include twisted, buckled, or distorted leaves with a whitish substance. Apply Sulphur-based fungicides as preventive rather than going curative. Start the crop on well moisture fertilised soil for crop to be strong. Do not carry out overhead irrigation. Do not grow crop under shades.

 

Bean Pests

 

Cutworm

 

Apply an insecticide late in the afternoon for best control. A mulch of neem leaves is useful against cutworms.

 

Bean Fly Control

 

Early planting prevents high damage which come later. Earthing /building up the soil around the plants to cover the roots at two to three weeks after emergence.

 

Chemical control using various systemic insecticides can be adopted.

 

Thrips Control

 

Adopt different cultural control methods like timely weeding, use of neem oil and botanical control like BotaniGard ES.

 

Aphids Control

 

Cut off and compost stems holding aphid clusters. Dusting the plants with flour constipates the pests. Do weed control early enough. When problem worsens chemicals can also be used.

 

White Fly Control

 

Remove weeds which hide the pests, maintain field hygiene after weeding and use of chemicals.

 

Pests at Bean Podding stage

 

Pod Borers

 

Most of the pod borers are damaging at caterpillar stage, like bollworm larva, Heliothis larva. Always destroy plant debris of previous crop by either using it in a compost pit or as animal feed. This ensure that the eggs laid there will not go on to the next growth cycle. Use plant-derived products, such as neem, derris, pyrethrum and chilli (with the addition of soap).

 

Sucking Insects

 

Plant sucking bugs occur from vegetative to early podding stage. The pests can be controlled by planting repellent plants such as parsley “dhania” and onions within bean plants.

 

Synthetic pyrethroids are effective, but will also kill natural enemies. Use plant-derived products like in pod borers.

 

When using chemicals, do not repeatedly use one type of insecticide to avoid resistance. Do NOT mix insecticides and foliar fertilisers in one spray tank.