Senior AgriPulse reporter Philip Brasher ran a provocative story in AgriPulse May 15, 2019 entitled “Blocked by GMO Politics, African Scientist Turns to 1950s Technology” (paywall, so no link possible).
It reports that Dr. Kingdom Kwapata, a plant breeder trained at Michigan State University, returned to Malawi to work on cowpea genetics. This legume, also known as black-eyed peas (see photo to right), has been an important drought-tolerant crop across much of Africa for hundreds of years.
The major cowpea insect pest is the pod borer. U.S. AID and the Gates Foundation funded a project began in 2016. In 2019, it has led to small field scale testing of Bt-transgenic cowpeas. If approved and commercialized, Bt cowpeas would be the second important human vegetable crop transformed to express Bt endotoxins (eggplant is the other).
Brasher’s report includes this passage —
“Kwapata said his Bt cowpeas will yield 1,300 kilograms per hectare, or about 1,160 pounds per acre, far above the average cowpea yield in Malawi of 450 kilos per hectare, or about 400 pounds per acre.”
This sort of claim regarding the benefits of new varieties — whether developed using conventional breeding or biotech — typically leave out three-quarters of the story. To produce 1,300 kilograms of cowpeas from a Bt-cowpea variety, the field would need to be properly fertilized. Other pests, and particularly weeds, would have to be effectively controlled. Rainfall and/or irrigation would have to provide sufficient soil moisture to produce such a bumper crop. Harvest operations would need to be carried out at the right time, and the crop properly cleaned and stored, so as to reach consumers in good shape.
Proponents of biotech like to attribute such impressive yield gains to the genes added to existing germplasm, when in fact achieving such higher yields depends on an optimal combination of many other factors and inputs. And such well-deployed inputs would also markedly boost the yield of a field planted using non-transformed cowpea seed.
But because of resistance to GE crop technology, Kwapata is exploring other methods to breed cowpeas better able to withstand or discourage feeding by pod borers. One of the methods is irradiation-induced mutation breeding, the 1950s-era technology referred to in Brasher’s story.
Brasher’s piece contrasts the random nature of mutation breeding to the “precision” of genetic engineering. Current GE transformation technologies, including CRISPR, are surely more precise than mutation breeding.
But as many items on Hygeia report, current GE methods fall far short of what the general public thinks the word “precise” means in the context of plant breeding — when one identified gene/trait is moved into a plant, the transformation triggers expression of just that trait, when and as needed, and no other impacts on the plant.
Food Safety Once Again Ignored
Brasher’s story is well done and important, but does not address a major reason why GE vegetable crops are still not widely planted anywhere in the world — food safety concerns.
Over 20 years ago, debate arose in Tanzania over U.S. food aid to Africa containing Bt corn. The reason was clear — how might the Bt proteins in the corn impact human health, given that:
- Corn makes up over 60% of the diet for many rural African families,
- Many rural people are undernourished, others are ill and have compromised immune systems, and
- Very little was known about what happens to the Bt proteins in GE corn as they move through the human GI tract.
It is widely accepted that Bt crystals break down quickly once in the human GI tract, but that is where the trail grows cold.
Before any country approves a Bt fruit or vegetable crop that will be consumed in a fresh or lightly cooked form, especially one that will be consumed frequently by pregnant women and children, there must be careful studies of Bt protein metabolism and exposure levels.
What levels of Bt proteins are expressed in the edible part of Kwapata’s cowpeas? What levels of human dietary exposure would be expected, given how many grams of cowpeas a family might consume in a day, or over a period of months?
What do Bt proteins break down to as they move through the gut? Whether and to what extent, and under what circumstances, might the Bt protein breakdown products cause problems in certain people?
Advocates of Bt fruit and vegetable crops contend that the U.S. regulatory system, and reviews of Bt corn and cotton, show no problems, and on this basis assert there are no reasons to be wary of Bt fruit and vegetable crops. Wrong.
They fail to either acknowledge, or understand that the risks to people consuming Bt cowpeas in Africa, or Bt eggplant in India, are bound to be different than risks arising in the U.S. population from Bt corn.
When was the last time you enjoyed a nice meal composed predominantly of #2 yellow field corn? Important GE food safety and human health research has been recommended for three decades by the U.S. National Academy of Sciences, but not funded or undertaken.
Hopefully, U.S. AID and the Gates Foundation will soon realize they bear some responsibility to invest in this needed food safety research to “balance out” their portfolios of grants encouraging Africa and Asia to develop and grow GMO food crops. Such research may fully exonerate the technology and show that long-standing risk concerns are unfounded. But moving ahead on a hope and prayer is irresponsible, and possibly even dangerous.
Philip Brasher, “Blocked by GMO politics, African scientist turns to 1950s technology,” AgriPulse (subscription required), Date published: 5/15/19, Date accessed: 5/28/19.