Dr. Linda Hall

2016 Agriculture,  Finalist

Innovating Herbicides, One Crop at a Time

To be successful, the cropping industry requires constant innovation from growers, machinery companies, chemical producers and crop breeders. In this working organism, the role of troubleshooter falls on the shoulders of University of Alberta professor Dr. Linda Hall.

“My work is anticipating and trying to solve the problems of herbicide resistant crops and weeds,” says Hall. 

This role is especially important because genetically modified (GM) crops are worth over $19 billion to the Canadian economy and Canada is the fifth largest producer of GM crops in the world. “Herbicides and herbicide resistant crops are a double edge sword,” says Hall. “Both control weeds while selecting for weeds resistant to herbicides.” To maintain this balance, weed eradication technology is constantly adapted to keep the weeds at bay and promote healthy crops.

Fighting Natural Selection

Developing herbicides is a race against the clock, since weeds are constantly evolving to survive controls. “What we’re doing is trying to kill one plant without killing the plant beside it. Herbicides are enormously useful in doing this, but of course natural selection occurs and the weeds evolve,” explains Hall.

This results in weeds being naturally selected, and soon the chemicals are no longer effective. “This became a big problem in the 1990s, and today it is increasingly problematic, with 55% to 60% of Alberta fields containing herbicide-resistant weeds,” says Hall.

One attempt at minimizing the issue of invasive weeds was the development of herbicide-resistant crops. However, this came with its own set of issues. “Canola and other herbicide-resistant crops can be weeds themselves, and we’ve had to develop solutions to combat this problem,” Hall explains. We are currently anticipating and trying to circumvent the selection of more weeds resistant to Roundup”.

Accidental Creation of Super Crops

One of the concerns of crop improvements is the unintended consequences of giving certain types of crops weed-like qualities.

Hall studies this issue by examining the gene flow in transgenic crops, which contain a gene or genes transferred from another species. “Plants have gene flow through pollen and seeds, and canola can transfer its genes from one crop to another,” says Hall. “So if you have one herbicide-resistant crop growing in a field and a different herbicide-resistant crop in the field next to it, gene flow can occur and create a multiple herbicide-resistant crop.”

This breakthrough discovery increased the agriculture industry’s awareness of the environmental consequences of genetically-engineered crops. With Hall’s research, crop developers can now proceed to create new strains of crops with a better understanding of how it will affect existing crops and the environment.