Tanzania’s GMO maize trial shows dramatic contrast

By Joan Conrow

October 17, 2018

Tanzania’s second year of confined field trials already shows a striking difference between the genetically modified and conventional maize varieties.

The trial of the drought-tolerant, insect-resistant TELA maize was nearly twice as tall as the conventional variety, which had been stunted by an attack of fall armyworm (FAW) and corn borers. The field trial is taking place at Makatupora, near Dodoma in central Tanzania, at a small government plant research institute down a remote dusty road.

The trial was intended to test the ability of the Bt gene to ward off the corn borer, so both the GM and conventional plants had been infested with stem borer larvae. The FAW, which is now decimating crops throughout Africa, came on its own, said Dr. Nicholas Nyange, chief research officer for the Tanzania Commission for Science and Technology.

Though the results have not yet been scientifically evaluated, the GM crop appeared to be thriving in comparison to the conventional variety. The stem borer and FAW had attacked both the leaves and tassels of the conventional varieties, causing stunting that would ultimately affect the yields. The GM plants were taller, with healthy tassels and verdant leaves.

“The fall armyworm will eat a plant all the way to the ground,” Nyange said. “It is a much worse pest than the stem borer. And it doesn’t like competition, so it will even eat the stem borer, too.”

About 50 to 60 percent of the maize grown in Tanzania is “organic” by default because the farmers cannot afford inputs, such as fertilizer or pesticide sprays, Nyange said. Though the government subsidizes them with fertilizer, it doesn’t always arrive at the right time, so farmers are advised to use animal manure.

However, most do not have sufficient livestock to adequately fertilize their crops, Nyange noted. Additionally, with nearly 70 percent of Tanzania’s population living in rural areas, the government is not able to reach every place or region.

Most farmers have only half-acre plots, so they are unable to grow enough maize to feed themselves, much less sell a surplus, Nyange said. The TELA maize is intended to help them improve their yields by providing built-in protection against some insect pests, without the need to spend scarce funds on pesticides.

The FAW infestation has been severe in Tanzania this year, Nyange said. “The government has spent a lot of money to make sure the insecticides are getting out to the farmers.”

However, pesticides are expensive and can contribute to environmental and human health problems. “That’s why we want to look at the [GM] technology to make sure we have the solution we need,” Nyange said.

A second trial later this year will test the efficacy of the drought-tolerant gene.