Bean bruchid is a pest that attack beans causing up to 40 per cent yield losses on affected produce. The pest starts attacking the pod while the crop is still in the field. It feeds within the bean making holes and reducing the weight making the produce unmarketable.
There are several ways farmers can control the pest to curb losses organically. In this, farmers will avoid use of pesticides. The World Health Organisation estimate pesticide poisoning rates at two to three people per minute.
One method of managing the pest organically without use of pesticides is by mixing dry bean grains with wood ash. In this, mix at the rate of five kilos of ash with a 90 kilogram bag of beans.
Farmers can also mix a teaspoon corn oil such as elianto with one kilogram tin of grains.
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Beans infested by bruchids
Smallholder farmers with one or two bags of beans living in a sunny area such as Eastern Kenya can reduce the pest’s infestation through sunning and sieving. This method kills the eggs and larvae and makes the adults fly away.
While sunning and sieving, spread out the beans on a mat under the sun for about six hours. After sunning, sieve the beans using a kitchen wire or a flat tin sheet with holes punched on it.
After harvesting, sieve the beans once every two weeks during the first three months. After three months, sieve the beans every three weeks.
According to Africa Soil Health Consortium, the bean bruchid is native to South America, but has spread to most other warm regions of the world. In Africa, the pest has caused widespread damage in Kenya, Lesotho, Malawi and Nigeria, and is also present in Angola, Burundi, DRC, Rwanda, Tanzania, Uganda, Zambia, and Zimbabwe.
In Tanzania for instance, the pest causes 40 per cent losses on beans annually.
By using the above methods, farmers save on costs that would have been used to purchase pesticides. When using actellic super pesticide for instance, a farmer will need to mix two match boxes full of actellic super with a 90 kilogram bag of bean grains.
Actellic super is sold by certified agro-vets in various towns across Kenya at between Sh120 to Sh1,000 depending on the quantity.
A 500g packet for instance retails at Sh860 by Simlaw Seeds Company, a subsidiary of Kenya Seed.