Question

What is dicamba and why has it been in the Arkansas news during the last year? Explain the issue. Essay form please

Answer 1

Dicamba Controversy When glyphosate, the active ingredient in Monsanto's Roundup, entered the market in 1974, farmers applied it sparingly - mostly to control weeds in row middles as well as in other places around their properties. It is a non-selective herbicide - it kills all plants - so spraying the crop haphazardly is a huge mistake. The limited use of glyphosate-based products kept the development of glyphosate resistant weeds in check for nearly 30 years. The herbicide is still very effective and in widespread use around the world, but scientists and farmers are trying to devise new strategies to stay ahead of constantly evolving weeds. This is where Dicamba enters the market. Dicamba is a broadleaf herbicide and was approved for use in crops in 1967. It works by mimicking a hormone called auxin, which controls cell elongation and division, and other processes that contribute to plant growth and development. The targeted plant takes up the herbicide and essentially dies from unbridled, non- coordinated cell division, metabolism, and expansion When properly applied, it is a clever weed management tool. Unfortunately, it is extremely volatile; it can vaporize after application Wind and temperature inversions can carry it to adjacent plants or even miles away, where it can impart its herbicidal effects Volatilization is affected by the pH and other ions present in the mixture, the nozzles used to apply it, the boom height above the crop, the temperature, humidity, wind and temperature gradients above the ground. In short, there are many factors that influence volatilization and off-target movement, which has led to endless claims of others' negligence in connecting responsibility to the tremendous crop losses In 2016 Monsanto first released a variety of dicamba-resistant cotton. The industry prefers to develop herbicide-resistant crops instead of new herbicides, because it's less expensive and presents fewer regulatory hoops to jump through. Nonetheless, Monsanto knew the older dicamba formulations were too volatile and would cause drift, so they developed a new product with "vapor grip technology that would minimize the problem. Monsanto and several smaller regional companies sell the new seeds. Monsanto, DuPont and BASF sell new formulations of dicamba to use in concert with the Genetically Engineered crops. Working in combination, the new seeds and herbicide formulations shouldn't have caused a problem. However, Monsanto released the dicamba-resistant seeds before the new herbicide formulations were available. Farmers could buy the seeds but not the new dicamba formulations. Monsanto explicitly instructed growers not to use the older, more volatile formulations. But some farmers. losing a battle to glyphosate-resistant weeds, illegally sprayed dicamba products on their new crop varieties, where it worked quite well. However, the tell-tale symptoms of dicamba damage began to show up on other farms. Various crops have remarkably different sensitivities to auxin-like herbicides, some showing the signatures of dicamba damage with 120,000 of the application rate. Much of the crop damage occurred in Arkansas, and the state baned dicamba. But farmers in dozens of states have reported crop damage to the EPA that is consistent with dicamba volatilization. Damage has been reported on both conventional and organic farms, including peaches, vineyards, tomatoes, and in huge acreage of non- dicamba resistant soy. In total it is estimated that 3.6 million acres of soybeans have shown symptoms. The situation is further complicated because it is unclear if minor symptoms (like a curled leaf) have anything to do with yield loss, where in other cases yield losses are clearly evident. Politicians and activists want to halt use of the technology, but this would be excessive. Rather, dicamba requires careful handling and further refinement. Manufacturers need to continue to improve the application formulac, study application conditions, and minimize off target damage to odd exceptions spawned from unusual weather events. Moreover, steps should be taken to compensate farmers for losses and earn the trust of ag producers and the general public In the end, this is a good technology that clearly was not ready for prime time. The silver lining is that independent experts quickly worked with farmers to identify the problem. Farmers, universities, the EPA and ag companies are now working (sometimes together to solve it. It is this kind of response that will ultimately make the use of any agricultural technology sustainable and provide the social license to use it. Source: Cameron English & Kevin Folta