Weeds Becoming Immune to Herbicides

What are Weeds?

Weeds are one of farmer’s biggest enemies, and to combat them is getting tougher every day. In defining what a weed is it is simple plants whose undesirable qualities outweigh their good points.With this in mind the ultimate goal is to have a weed free field which would produce higher yields and better profit for the farmer. weeds compete with already planted crops for water, nutrients and space. Weeds are able to grow rapidly and spread quickly throughout fields if not treated. Farmer’s best chance at fighting weed invasion is by spraying chemicals that will get rid of the pervasive plants or weeds.

I was recently reading an article on the web that had a story on herbicide-resistant weeds written by Jason Koebler, a writer for U.S. News, called Herbicide -Resistant 'Super Weeds' Increasingly Plaguing Farmers. This article can be found at USNEWS.COM. The author talked about how farmers today are facing some hard time with battling weeds that are now resistant to the chemical which killed them in the past years. They are called super weeds. Having weeds that are herbicide-resistant causes huge problems for farmers. The author interviewed a farmer who said, "I have weeds that are now eight feet tall , they're the diameter of my wrist, and they can stop a combine in its tracks." Most farmers use roundup ready corps, aka glyphosate, which means the crop is resistant to the herbicide, but he weeds around should be killed when exposed. 

Glyphosate or Roundup

Glyphosate is effective in killing a wide variety of plants including grasses, board-leaf, and woody plants but at the same time being one of the most environmentally safe herbicide. Glyphosate inhibits a certain enzyme called EPSP synthase that causes production of essential proteins for growth. With out the ability to produce these proteins the plant will yellow and die. By volume, it is the most widely used herbicide. Now after 24 years some weeds have evolved and become resistant. This means farmers have had to return to some herbicides which are less environmentally safe that were given up many years ago.

Effects on Farmers

The author stated, "Farmers are turning to more traditional methods of weed management, such as using cover crops, crop rotations, and physically pulling weeds to lessen their reliance on Roundup. But those solutions are time consuming and expensive," I agree with this statement, some of these weed management practices could be effective but most are not practical solutions for most large scale farmers. It would require unsubstantial amounts of man/woman power on a large farm to go out and physically pull weeds, and would be ineffective in the long run.

Another problem that was mentioned in the article was other chemicals being used to fight the weed war, and how they are more potent than Roundup. In the article Jason mentions, "As Roundup loses effectiveness, farmers are turning to 2, 4-D, and older herbicide that some say is more dangerous to humans and has been shown to cause birth defects in animals exposed to the chemical." With trying to control these super weeds, farmers are faced with choices that can possibly not only affect themselves but other humans and environment around them. There is always going to be an ongoing battle in research and development for chemicals that will replace and actually work on certain chemical resistant weeds, but this also take time to create.

How can we obtain new chemicals to control these weeds?

There are a few herbicides that will kill weeds that roundup is used for.  However, for the weeds that are unable to be killed by anything on the market today, there is research being done everyday to try to stay one step ahead of the game in the effort to control weeds.  The only problem that researchers are having is that, from start to finish, getting a new herbicide on the consumer market can cost up to and possible more than 50 million and take anywhere from eight to ten years.