The ever-increasing bounty of agriculture has been with us as long as I can remember, but it may have finally hit the dreaded Peak, according to a new study published in CropScience by Robert Graybosch, a geneticist at the University of Nebraska and James Patterson, a geneticist at Oregon State University.
Genetic improvements have increased wheat yields about 1% each year since the late ’50s. But in 1984, several scientists noticed that the average yield improvement seemed to have slowed, in a sign that genetic gain was plateauing.
Graybosch and Patterson then went back in and made a more detailed study, carefully analyzing the last 50 years of data collected by the Department of Agriculture. They found that ever since the early ’80s, genetic gain has continued to steadily drop. And now it appears to have come to a halt.
About 68 million metric tons gets harvested in the US every year. There’s only two ways to get more. One is to increase the amount of land devoted to growing wheat. The other? Breeding efforts, like making it mature at ideal times, resist fungal infections, and divert more energy into making grain. We seem to have exhausted option two, if these scientists are right.
1. Faster breeding pathogens, evolving more quickly than plant breeders can fight back
2. Possibly, breeding itself has weakened wheat by reducing the gene pool
Wheat has not been subjected to genetic modification, as have corn and soy. Wheat’s genome is very complex.
Directly altering wheat DNA with genetic modification could fix the problem, but it is not a choice that is popular, says Graybosch. Other options: plant more land, use more water. They don’t sound so great either.