Ghanaian scientists have completed field trials on the pest-resistant Bt cowpea and will soon apply for commercial release of the country’s first genetically modified (GM) crop.

The GM crop is expected to help farmers dramatically reduce their use of pesticides, while also enjoying better yields of this important staple food.

Scientists said the trial results are currently being reviewed, after which an application for commercialization will be submitted to the National Biosafety Authority.

Currently, the scientists are producing more seeds of the pod borer-resistant cowpea variety to scale up production when the greenlight is eventually given for commercial release.

“Now, we are trying to multiply our Bt cowpea seeds in order to have enough seeds so that once regulators give the go ahead for release, we know that we have enough seeds to give whoever wants seeds,” Gloria Adazebra, a plant breeder on the Bt cowpea project in Ghana, said during an Alliance for Science visit to the trial site.

Destructive insect pest

The Bt cowpea variety developed by the Savannah Agricultural Research Institute (SARI), a state research body, has shown a high level of resistance to the destructive maruca pod borer, which can destroy up to four-fifth of yields on cowpea farms.

“It has been very difficult to control these pests because it has a cryptic feeding habit and you can get very drastic reduction in your yield,” Dr. Mumuni Abdulai, principal investigator in charge of the Bt cowpea project, told Alliance for Science. “It can cause loss of up to 80 percent of farm yields. It feeds on the flower buds and flowers. And it’s difficult to spray them with chemicals. Over the years, it’s been very difficult to control the pests with pesticides as farmers have to spray insecticides heavily on the fields.”

Cowpea, popularly called beans, is a common and important food in Africa. Nearly 200 million people consume it on the continent. It is rich in protein and has high energy content, making it a good source of nutrients for both humans and animals. It’s usually cooked and eaten with carbohydrate sources like plantain and rice.

Destruction by the maruca pod borer pests has been responsible for very low yields on cowpea farms in Ghana and across sub-Saharan Africa. They are particularly devastating because they damage not only the flowers and the buds, but also destroy the pods, resulting in grain and yield loss.

“At a very young age, the pest causes destruction to the plants,” Ibrahim Lansah, a cowpea farmer at Nyankpala in the northern region of Ghana, told the Alliance for Science in an interview. “They bore holes in the plants. It’s a very dangerous pest. We spray them every week for three months. That’s 12 times of spraying every season.”