several biopesticide products for use against the fall armyworm, and biopesticide trials are under way in many other countries.
Our study assessed more than 50 biopesticide active ingredients which have been registered in fall armyworm’s native range in the Americas as well as in some African countries. We reviewed the literature and regulatory documents with the aim of answering five key questions: Is the biopesticide effective against fall armyworm? Is it of low risk to human health and the environment? Is it sustainable? Is it practical for use by small-holder farmers? Is the biopesticide available?
We identified 23 active ingredients that we recommended for further consideration. We also identified eight active ingredients that should be brought to market. These include products containing neem plant extracts and Bacillus thuringiensis, two of the most widely used biopesticides globally. This includes fast-tracking product registration, as well as reviewing and updating information materials and recommendations for farmers, as well as taking into account availability.
More needs to be done if biopesticides are going to replace chemical pesticides. For example, in the medium-term, governments will have to assist farmers by subsidising biopesticides, an approach being adopted by Ghana. They could consider local production of biopesticides, working in partnership with the private sector.
There are a host of challenges too. Few biopesticide products are registered for use in African countries. And most of those registered aren’t widely available or affordable, particularly for smallholder farmers. While some farmers might be willing to pay a premium for a lower risk product, many smallholders have such small margins that they will seek to minimise production costs. So older, off-patent and cheaper pesticides might be preferred, despite the dangers.
With greater support from governments, research, the private sector and NGOs, a market for lower risk products could be developed, which would lower prices. Ultimately, biopesticides present an opportunity to lower not just the economic cost of controlling fall armyworm, but also the cost to the environment and human health.
Such an approach should fit into a broader drive to control fall armyworm by using a more integrated approach that combines a variety of agricultural practices. Known as integrated crop management, the approach involves combining a range of practices with an emphasis on those regarded as “low risk” compared to conventional chemical pesticides.
This could include closely monitoring the crop, intercropping, manual removal, biological control, insect-resistant varieties and traditional methods such as applying ash. Dr Melanie Bateman, lecturer in ICM Master’s programme on jointly organised by CABI, University of Neuchâtel, Switzerland. Roger Day, programme executive at CABI, also contributed to this article.
A FARMER in Bubi, near Bulawayo, Zimbabwe, shows the damage to his maize crop caused by the fall armyworm.