A €7.66 million research and innovation project is expected to promote ‘push-pull technology’, an eco-friendly approach to use some ‘repellent plant species’ in combating pests that attack different crops in Rwanda, Ethiopia, Kenya, Uganda, and Tanzania.
The project dubbed "UPSCALE” will be implemented by Rwanda Agriculture and Animal Resources Development Board and Food for the Hungry – a Christian international organisation – in the districts of Kamonyi, Muhanga, Ruhango, Gatsibo, Nyagatare and Ngororero.
It is aimed at addressing food security, livelihoods and climate change resilience in the sub-Saharan region of East Africa, while reducing the environmental impact of agricultural practices through agro-ecological management based on push-pull technology.
Germain Nkima, a researcher in pest management at Rwanda Agriculture and Animal Resources Development Board said that researchers are working on nature-based solutions such as push-pull technology to control maize stem borer pests in Rwanda.
Push-pull is an integrated cropping system that involves driving pests away from the main crop using a repellent intercrop.
He explained that Desmodium plants are intercropped with the rows of maize while there are other species planted surrounding the land of maize crop.
Desmodium produces volatile chemicals that repel or push fall armyworm moths from the crop while other plant species such as elephant grass surrounding the maize farm pulls the fall armyworm.
"Once the fall armyworm reaches elephant grass, this plant species has thorns that kill the fall armyworm moths and stop reproduction and then reduces armyworm population,” he said.
Agricultural experts say that push-pull technology also improves soil health and water retention, provides economic and high-value livestock fodder, and increases system resilience to climate change.
Nkima said that the technology could help the country defeat armyworms in an environmentally-friendly manner.
"Since 2017, Rwanda faced an unusual invasion of fall armyworm but we used chemical pesticides as the last resort because we should be using other environmental friendly techniques,” he said.
Saving bees
The pesticides, he said, are harmful to the environment because they kill other biodiversity species that are important in ecosystems such as bees that increase agricultural productivity.
"Therefore we are seeking natural-based solutions to control the pests which don’t kill other species,” he said.
Farmers say that use of chemical pesticides killing armyworms has also killed bees leading to huge losses.
According to KODURU-beekeeping cooperative pesticides used in killing armyworms has triggered a loss of 3.5 tonnes of honey so far in Nyaruguru district.
Besides the effects of chemical pesticides on honey production, agricultural productivity could decrease following the affected pollination system according to researchers.
The "Thematic Assessment of Pollinators, Pollination and Food Production”, a two-year study carried out under the auspices of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) revealed in 2016, that global crop production with an annual market value of $235 billion–$577 billion is directly attributable to animal pollination.
But despite their good impact on crop production, the pollination species ‘are not entirely in safe hands’.
The study shows that 16.5% of vertebrate pollinators are threatened with extinction globally and over 40% of invertebrate pollinator species – particularly bees and butterflies – are facing extinction by diverse pressures, many of them being human-made such as pesticides (mainly insecticides), which leads to the loss of hundreds of billions of dollars annually as pollination- dependent crop yield fails.
Nkima said that using eco-friendly techniques- in fighting pests being fuelled by climate change- could both save pollination species and increase agricultural productivity.
"Climate change is triggering pests and crop diseases that we didn’t experience before. Using pesticides to control pests and diseases is posing another threat to biodiversity and therefore researchers are trying nature-based solutions,” he explained.
The research started in Gatsibo district to have model farms.
Gloria Mutoni, the Director of Projects at Food for the Hungry -a Christian international organization said that the research on the push-pull technology pilot was piloted in Gatsibo district.
"We are working with 160 maize farmers to carry out research and demonstrations on nature-based solutions to control the pests. It will help to get information whether it is really helping farmers. Once the demonstration is successful, researchers and policy makers will then promote the technology,” she said.
Pascasie Uwizeyimana, a farmer in Nyagihanga sector in Gatsibo sector said that Push-Pull technology is bearing fruits.
"Whenever I would grow maize of a half hectare, I would harvest 500 kilogrammes of maize due to the invasion of armyworms. Today I harvest over one tonne of maize using push-pull technique to combat armyworms,” she said.
John Bugenimana, another farmer, added "We first plant desmodium and elephant grass and maize later. The plants fight armyworms and also increase milk productivity as they are fodder for our cows. On 50 acres where I used to harvest 400 Kilogrammes, the yields have doubled to 900 Kilogrammes. ,” he said.