Malawi is no stranger to shocks, natural disasters, and agricultural pests, but the latest to threaten the country’s agriculture and food security is fall armyworm (FAW).
The pest native to South and Central America has worked its way across African, reaching Malawi by December 2016.
While FAW has fed on over 80 plant species in the country, including cash crops such as cotton, its attack on staple crops like sorghum, millet, and especially maize, is most worrisome.
Unfortunately, Malawi’s maize-dominated cropping system—with its uniform plant tissues and populations—does not include natural barriers that diverse, intercropped systems have. This makes it more vulnerable to aggressive pests like FAW that expand and flourish quickly.
As of February 1, estimates showed that 382 000 hectares of maize, sorghum and millet have been affected by FAW nationwide, impacting over one million farm families, according to Albert Changaya, controller of agriculture extension and technical services at the Ministry of Agriculture, Irrigation and Water Development.
Roughly 10 percent of this years’ dry season (non-irrigated) maize is expected to be lost to FAW, double last year’s damage, according to the ministry.
Government has prioritised pesticide distribution as one component of the immediate response to FAW.
Along with development partners, it has provided some pesticides for free to farmers in addition to training for farmers, extension workers, and supporting agencies on their correct use.
Still, the efficacy of pesticides varies considerably based on the timing and method of application, dilution rates and the stage of its life cycle at which the pest is sprayed.
Not to mention, applying pesticides is costly and poses potential human and environmental risks, especially if not applied correctly.
According to entomologist George Phiri, the assistant representative at the Food and Agriculture Organisation of the United Nations (FAO), farmers must be trained to scout their fields and assess the severity of FAW damage to decide how best to handle the pest and whether spraying is necessary.
While pesticides certainly have a place in the immediate response, the government has a plan for large-scale adoption of an Integrated Pest Management (IPM) approach, which combines its short-term emergency measures with longer-term strategies.
“There is no single solution for FAW control,” said Jean-Pierre Busogoro, an agricultural scientist with the European Union delegation in Lilongwe. “We need to understand the interaction between pest and crop and we need an integrated strategy,” to promote a healthy, resilient, and nutrient-rich crop environment containing pests’ natural enemies.
Addressing FAW in the long term requires adoption of good agronomic practices, including timely planting before FAW populations build up, according to Phiri.
He stresses the need to promote vigorous early plant growth coupled with early detection and treatment of FAW. The older a crop gets, the lower the chances of successful pest control.
Intercropping and more diverse cropping systems can also help slow the spread of FAW and other pests and diseases by providing a barrier of non-compatible plant tissues that may not be edible to the pest, Busogoro said.
One intercropping technique that has proven particularly successful in controlling FAW is the “push-pull” approach, originally developed to control the cereal stem borer, another pervasive pest.
It involves intercropping cereals (like maize) with insect-repellent legumes of the Desmodium genus (give examples), along with a forage plant, like Napier grass.
The legume repels or “pushes” pests away from the primary cereal crop while the grass serves as an enticing border that “pulls” them away.
Sometimes, less is more. The simpler and more accessible a solution is, the more likely it is to be taken up and sustained in the long term, after external funds and subsidies cease.
As Busogoro suggests, FAW—and other pests and diseases—can ultimately be neutralised if we focus on “simple technologies, adapted and accessible for the majority of farmers.” n