RWANDA – Maize farmers in Rwanda have expressed concern, arguing that despite government interventions on taming the fall armyworms, the pests are building resistance to common pesticides.

Fall armyworm is an insect pest that feeds on more than 80 crop species, causing damage to cereals such as maize, rice, sorghum, and legumes, among others.

According to farmers, of the three common pesticides used, the pests have been shown to be resistant.

“When we use these pesticides when armyworms have already attacked the maize crops on a vast scale, they resist.”

Evariste Tugirinshuti, the president of Rwanda Maize Farmer Cooperatives Federation told The New Times that farmers have now resorted to spraying these pesticides at early stages when the pests are not yet at vast scale in the maize plantations.

Some members of COOPROMASA —a cooperative that grows maize and soybeans in Gatsibo District — reported that they applied Rocket pesticide but the armyworms didn’t die.

According to Tugirinshuti, the pests resisted the pesticide leading to some farmers losing between 20 percent and 40 percent of the produce in the previous season.

RAB explains armyworms’ resistance

According to the Rwanda Agriculture and Animal Resources Board (RAB) in Musanze District, an assessment has to be carried out on the existing pesticides.

Meanwhile, Athanase Hategekimana, in charge of combating crop diseases and pests at RAB, advised farmers “not to use one type of pesticide consecutively.”

“When farmers keep using one type of pesticide all the time consecutively, the fall armyworms end up resisting.

Farmers should try using different types of pesticides by alternating them. If one type is used this season, next season they can change and use the other,” he explained.

He said good agriculture practices are currently needed on 260,000 hectares to be planted with maize across the country, adding that those capable can also use traps of armyworms.

Rwanda considers biological control agents 

Rwanda is also considering using biological control agents (parasitoids) that are insect predators, to effectively contain the fall armyworms that are ravaging maize crops across the country.

In January, Athanase Hategekimana, the scientist in charge of combating crop diseases and pests at RAB noted that the fall armyworms devastated maize crops during the current Agriculture Season that started in September last year.

Hategekimana disclosed that Rwanda, since December last year, has begun to work with the International Centre of Insect Physiology and Ecology (icipe) to strengthen the capacity of extensionists to be more able to support farmers to effectively contain and manage the fall armyworm by using biological control agents.

“These biological control agents or parasitoids were used in neighboring countries such as Kenya and Tanzania to combat armyworms. The parasitoids or predators lay their eggs into fall armyworms’ eggs and then armyworms do not reproduce to affect crops,” he explained.

RAB said it is multiplying the parasitoids or predators in laboratories and conducting confined trials in Bugesera district and Kigali city before deployment to farmers.

Moreover, agricultural scientists in Rwanda are pushing for genetically modified (GM) seeds that could help fight against pests, diseases, and drought that are devastating major crops in the country.

These genes provide beneficial traits such as pest resistance, the ability to grow in extreme conditions, and increased nutrient levels.

Rwanda, in July 2023, took a step towards regulating genetically modified organisms (GMOs) with the introduction of a new draft law governing biosafety.