GM weapon in war against fall army worm threat unveiled

Thursday July 12 2018

Pesticides being loaded onto a Rwanda Defence Forces helicopter to be airlifted to different parts of the country. PHOTO | CYRIL NDEGEYA | NMG


Maize was not always grown in sub-Saharan Africa. A plant native to the Americas, it arrived here about 500 years ago.

But all around us, there are constant reminders that today, maize is sub-Saharan Africa’s most important food crop.

You will see drivers sitting in afternoon traffic eating a roasted ear of maize they bought from a street vendor.

Wherever there is a spare patch of earth — in someone’s yard, even just on a narrow strip next to the road — you will see telltale stalks of maize plants growing in carefully tended rows.

And wherever you eat, the meal is likely to feature a stiff porridge-like dish made from corn flour, known as Ugali in East Africa, Nsima if you are in Malawi, Kenkey if you are in Ghana or Tuwo Masara in other parts of West Africa.

But today, sub-Saharan Africa’s favourite adopted crop, a staple food for half the population that is grown in 46 of our countries, is in big trouble in the form of a voracious caterpillar that, like maize, made the crossing to Africa from the Americas.


But while maize brings life, this caterpillar brings death. Experts in crop pests call it the fall armyworm because it swarms across the landscape like a large army, invading and destroying maize, its preferred food, with military precision.

A farmer can look out on her fields one day, confident her maize is healthy and standing tall, yet two days later, she is ruined.

With each female worm capable of laying 2,000 eggs in its two-week lifespan, it has taken the fall armyworm just two years to spread to almost every country on the continent. Experts warn that it could destroy 20 million tonnes of maize in Africa each year. That is enough to feed 100 million people.

In Uganda, I worked with a team to develop maize that could resist the crippling maize streak virus disease. But the fall armyworm may be one of the biggest threats to food production in sub-Saharan Africa.

We urgently need solutions. Insecticides are a potential option, if available and affordable. But their effectiveness is limited by the fact that, before sitting down to dinner, these worms burrow deep into the ear of the corn where insecticides often do not reach.

Ultimately, the farmers are going to need many different tools to push back these invaders.

One that may soon be available to farmers holds enormous promise. It is a type of maize that is just like the varieties of maize that farmers have been growing here for centuries, but with one very important difference.

This maize has been genetically endowed by plant breeders with built-in protection against insect pest attacks.

The protective gene is derived from a common bacterium found naturally in the soil that is called bacillus thuringiensis, or just Bt for short.

Bt is harmless to humans, livestock and animals, so much so that organic farmers have been spraying it on their crops for decades as a natural way to control crippling pests.

But for fall armyworm, Bt maize is often lethal. And unlike sprayed pesticides, Bt maize springs its attack from deep inside the maize plant, making it more effective.

Several varieties of Bt maize have been developed by the African-led, public-private partnership called Water Efficient Maize for Africa (Wema).

In addition to developing drought-resistant crops, Wema scientists are also using their deep knowledge of maize to fight productivity limiting pests such as stem borers and fall armyworm.

Wema Bt maize varieties are now being tested in Uganda, Kenya, Mozambique, Tanzania and South Africa.

The Wema varieties have proven far less vulnerable to damage from armyworms than the maize varieties that most farmers currently grow.

Farmers in South Africa are already planting Bt maize. We are now working in several other countries to provide whatever is needed to conduct a thorough and independent review of any safety concerns and answer farmer and consumer questions.

Bt maize has been safely produced and consumed in the Americas for decades.

Still, African countries need to conduct their own, independent assessments and make these varieties available to the millions of farmers who depend on maize for their livelihood.

Over the longrun, fall armyworm will need to be managed through an integrated, holistic package of solutions that give farmers options for protecting their maize. But speed is crucial. Fall armyworm is a vicious predator that is spreading fast.

Bt maize represents a near-ready solution that is already known to work against the fall armyworm. And it can be used as part of a comprehensive package of crop management interventions.

We are hopeful our leaders will review the scientific evidence and give more African farmers the option of choosing Bt maize to help protect themselves from this alarming threat.

Denis T. Kyetere is the executive director of the African Agricultural Technology Foundation.