Super weeds are a threat to global food production

Scientists at Bayer Crop Sciences' weed resistance panel made it abundantly clear that herbicide resistance is not a U.S. phenomenon.

Speaking at the Farm Progress Show in Decatur, Steven Powles, University of Western Australia, noted the super weed problem is a global threat. Looking at the top grain exporting countries -- U.S., Brazil, Canada, Australia and Argentina (in that order) -- all are facing herbicide resistance issues.
  
"Weed resistance is basically a threat to world food production," Powles noted.
 
The U.S. is tops in terms of herbicide resistance challenges. However, Brazil is experiencing significant challenges too. Pedro Christoffoleti, University of São Paulo, said problems with ALS chemistries started in the mid-1990s.

Glyphosate-tolerant crop systems helped when first introduced in Brazil. However, the country now has five glyphosate-resistant weeds.
  
Illinois problems
   
In Illinois, weed resistance is a serious problem, and it looks to become a bigger one in the near future.
   
Aaron Hager, a weed scientist with the University of Illinois, said waterhemp is currently causing the most headaches. To date, U of I has confirmed waterhemp plants with resistance to five different herbicide chemistries.
   
"Multiple resistances within the waterhemp plant is where this is going," Hager added.
  
U of I has confirmed two waterhemp populations with stacked resistance to four different chemistries. Three-way stacks are more common.
   
 "If you have a plant like this that comes up in a soybean field, you have no way to chemically manage that weed," Hager said.
   
Future chemistries
   
Lastly, growers shouldn't expect any new herbicide chemistries in the near future.
  
Bayer CropScience's Harry Strek said if a new chemistry were discovered today, it would take a minimum of 10 years to bring to market. Hager noted the last new chemistry (HPPD inhibitor) was discovered in the 1980s.
   
The first HPPD herbicide didn't arrive until the early 2000s. Hager said the lag is indicative of the time it takes to fully test and optimize a new chemical molecule.

Along with the time component, cost is also a challenge. Hager said corporations can expect to spend $100 to $200 million before any costs are recovered through chemical sales.