Most smallholder farmers surveyed in Uganda believe they can reduce damage caused by the fall armyworm with several management and control options available to help them mitigate the impacts of the potentially devastating crop pest.
Smallholder farmers in Kamuli and Namutumba districts of the country strongly considered the fall armyworm (Spodoptera frugiperda) to be a threat to maize production since it was first recorded in Uganda in 2016.
But those surveyed said they believe they can manage the pest effectively if they have the appropriate and efficacious chemical insecticides and are able to correctly apply them and follow recommended procedures, according to research published in the journal CABI Agriculture and Bioscience.
While 84% and 90% of Kamuli and Namutumba respondents respectively, predominantly use chemical control methods – other methods included regular weeding and handpicking. The use of biological extracts – such as pepper, tobacco, Aloe-vera, Lantana and sisal – though evident, were not common.
In Uganda, maize is one of the most important cereal crops and smallholder farmers usually engage in maize growing for food, as a cash crop, and as an important export crop.
Over the years, production of maize has increased from 2.8 million metric tonnes in 2015 to 4 million metric tonnes in 2017 as a result of the increased demand for maize and other maize products, and the favourable climate that enables two cropping seasons in a year.
However, maize is attacked by numerous pests and diseases during the growing cycle – including the fall armyworm – with infestation level and incidence dependent on weather factors, soil conditions, interactions with other arthropod species, and the level of resistance/susceptibility of the maize varieties.
Dr Andrew Kalyebi, lead author of the research said, "This study documented practices that have been successful and unsuccessful in managing the FAW since its invasion of Africa using Uganda as a case study.
"Through the interviews we document the diversity of actions employed by farmers to combat FAW, and their perception on whether pest control efforts are successful.
"This knowledge is critical for designing sustainable pest management strategies for this highly destructive agricultural pest that may have a high chance of being adopted by farmers. This work also provides insights that might be useful in other farming contexts where FAW has only just arrived or is yet to invade."
The scientists, who also include those from the National Crops Resources Research Institute (NaCRRI) and The Commonwealth Scientific and Industrial Research Organisation (CSIRO), suggest that application of insecticides at high frequencies could lead to the development of resistance in the fall armyworm population either singularly or in combination with other insecticides as it increases the selection pressure.
Indeed, in their research, they found that some insecticides (such as lambda-cyhalothrin and emermectin benzoate) found commonly used by the farmers against fall armyworm in the districts and considered effective, are also considered high risk to both human and environmental health.
Dr Kalyebi added, "The Government needs to sensitize farmers to regulate their use (dose rates vs. frequency of application), regulate access along the supply chain and find better safe alternatives in order to mitigate some of the health and environmental risks associated with their use.
"It is important that some research is conducted to test for resistance traits in local field populations of fall armyworm to document the extent of resistance and prepare neighbouring regions."
He stressed that while farmers' confidence in dealing with the fall armyworm is a positive sign, they must remain vigilant that this confidence is not undermined by the development of widespread resistance to popular insecticides.
"The continuous sharing and transfer of this experience, knowledge and technologies by farmers coupled with more research efforts to develop novel control options, including exporing efficacies of endemic ethnomopathogenic fungi, will contribute to the development of long-term sustainable management of the fall armyworm," Dr Kalyebi said.
Additional information
Main image: Fall armyworm on maize (Credit: CABI).
Full paper reference
Kalyebi, A., Otim, M.H., Walsh, T. et al. Farmer perception of impacts of fall armyworm (Spodoptera frugiperda J.E. Smith) and transferability of its management practices in Uganda. CABI Agric Biosci 4, 9 (2023). https://doi.org/10.1186/s43170-023-00150-w
The paper is available to view open access here: https://rdcu.be/darvS
