If farmers stopped using herbicides many environmental groups would be pleased, but consumers may not rejoice because food would be much, much more expensive.
A Weed Science Society of America study has concluded that corn yields would drop by 52 percent and soybean yields by 49.5 percent in the U.S. and Canada, if producers didn’t use herbicides and other weed control measures.
The reduced yields represent $43 billion (US) in crop production losses, per annum, based on a corn price of $4.94 per bushel and soybeans at $10.61 per bu.
“It’s an astonishing number and indicates the significant threat weeds present to crop production,” says Anita Dille, Kansas State University weed scientist and study lead author.
“It also drives home the importance of taking steps to mitigate the development of herbicide resistance.”
A University of Guelph weed scientist, Peter Sikkema, was a co-author of the paper. Sikkema helped compile yield loss estimates for Ontario, assuming no herbicides or other weed control methods:
- Ontario corn yields would decline by 51.4 percent
- Across Canada, the lower yields would reduce farm income, from corn, by $500 million
- Ontario soybean yields would drop by 38.1 percent
- In Canada the cut in soybean production would lower crop receipts by approximately $1.0 billion
- In Canada and the U.S. the lack of weed control in soybeans would potentially cost farmers $16 billion in production losses
- In corn, the estimated losses are $27 billion
The yield declines in corn and soybeans may overestimate the yield impact of weeds on other crops. Corn and soy are row crops and are more dependent on herbicides than the cool season crops of Western Canada.
“Our wheat, canola, winter-wheat and a lot of our cereals are very competitive (with weeds),” said Jeanette Gaultier, Manitoba Agriculture weed specialist.
The complete paper, on corn and soybean losses because of weeds, will be published in an upcoming issue of Weed Technology.