Using Brachiara grass and Desmodium to control Fall armyworm

BY MWANGI MUMERO

Growing Brachiara grass and Desmodium, a legume fodder, together with maize, can help to control the Fall armyworm pests, which continue to devastate cereal farming in many parts of the world, a new report says.

It is based on the findings of researchers from the International Centre for Insect Physiology and Ecology (Icipe) and United Kingdom’s Keele University.

In a pull-push technology, Desmodium acts as the push plant against the Fall armyworms. It releases chemical scents that ward off the moths, preventing them from laying eggs on the cereal crop.

Therefore, the chances of pest populations building up are reduced. “Desmonium and Brachiara act as a ‘push’ plant that repels the Fall armyworm. Both also produce chemicals that attract (pull) natural enemies of the Fall armyworm,” observes Prof Toby Bruce, of Keele University, one of the researchers involved in the study.

Field evaluation reports have confirmed that this ‘pull-push’ innovation showed the armyworm infestation to be 80 per cent lower in plots where it was used compared to mono-cropped maize plots without the technology.

The findings affirm that this agricultural innovation exploits natural insect–plant and insect–insect interactions and can be used to improve the cereal-livestock mixed farming systems.

Besides preventing the Fall armyworm, farmers also benefit immensely from this technology. Brachiara grass and Desmodium are nutritious livestock fodders.

The grass also controls soil erosion, while Desmodium suppresses Striga weed, a noxious weed associated with cereals.