More Herbicide-Resistant Crops in Pipeline

Crop protection companies have consistently explained how it takes more than 10 years to bring a new crop technology to the market once a proven candidate has been identified, but it has taken companies exceptionally longer than 10 years to use biotechnology to develop crops resistant to more than two herbicides. Now, additional herbicide/crop-tolerant systems are on the verge of introduction.

Roundup Ready crops from Monsanto were the first herbicide-resistant crops. For more than a decade, the company has dominated the herbicide-tolerant seed market and the herbicide market with glyphosate-based formulations.
Liberty Link came along second and only recently has Bayer CropScience powered up its original Liberty herbicide into Ignite (glufonsinate active ingredient) for non-selective use over the top of corn, cotton, soybeans and canola. The company is also proceeding with research to insert the genetic herbicide resistance into more crops than those three.

Selective Herbicide Tolerance
Now that weed resistance and tolerance to glyphosate has started to be a major issue, companies with biotech research programs have seen the value of developing crops resistant to selective herbicides those herbicides that can control a limited number of weeds. What's important is that tolerance of crops to those selective herbicides will give growers an option of staying with a total post-emergence herbicide program while controlling weeds showing signs of tolerance to glyphosate.

"Today, the major challenge for glyphosate is broadleaf weeds. It is just not performing like it used to," said Larry Robertson, senior marketing specialist U.S. herbicide tolerant traits for Dow AgroSciences. He also noted how a few grassy weeds are also showing tolerance to glyphosate.

For those reasons, Robertson sees Dow AgroSciences' new herbicide-tolerant trait technology as being agronomically successful for growers when stacked with glyphosate tolerance traits in the seed industry's elite corn hybrids and its best soybean and cotton varieties.

2,4-D Tolerance
The new herbicide-tolerant trait technology will infer tolerance to 2,4-D herbicides in corn, soybeans and cotton. In corn, it will also infer tolerance to "fop" grass herbicides, such as Targa or Assure, that contain the active ingredient of quizalofop. Crop resistance to glufonsinate herbicide will also be included in commercial soybean and cotton seed, and in selected stacked corn seed.

"Tolerance to 2,4-D fits really, really well with a glyphosate-tolerant system because 2,4-D is a very cost-effective herbicide component," Robertson said. "We think we have the best offering when it comes to cost-effective weed control that fits together with how growers want to continue to use glyphosate."

He calls it a leader of the next wave of herbicide-tolerant traits coming to market. "Depending on regulatory approvals, in corn, our target is to have an introduction in 2012 with more commercial quantities in 2013. In soybeans, we are looking at 2014 as a target timeline, and in cotton it is a little further out, probably 2015 or 2016."

Coming to market in conjunction with the 2,4-D tolerance herbicide trait will be new 2,4-D herbicide technology, Robertson explained. "We can assure growers that our novel 2,4-D formulations will not be the 2,4-D of today. There is going to be some significant technical advances." The focus of research and development with 2,4-D is volatility, physical drift and odor.

Two Companies and HPPD
Bayer CropScience has continued its research and development in regard to identifying the genes necessary to impart herbicide tolerance to crops. Being involved in that research requires looking at the more than 20 modes of action that can be used to affect plants, of which only about eight have been commercially developed, according to Hermann Stübler, site director and director of herbicide research, Bayer CropScience, Germany. "Some of them have been explored for a long time, and in many cases, economical requirements will not be fulfilled" for them to be commercialized, he said.

Bayer CropScience has made breakthroughs in inferring crop tolerance to HPPD inhibitor herbicides, the mode of action for many of the company's most recent selective herbicide introductions. Stübler said, "HPPD herbicide tolerance technology is based on changes in the target site" so that the active molecule cannot bind within the plant's receptors. The company is hopeful of launching the first non-selective and selective herbicide triple stack of Liberty Link, glyphosate and HPPD-tolerance crops in 2015.

Syngenta is also working on crops that are resistant to HPPD herbicides because it sells HPPD inhibitor mode of action products, too. Callisto is the most commonly known Syngenta HPPD herbicide while the Bayer CropScience brands include Balance Pro and Laudis. Impact is an HPPD inhibitor brand from AMVAC, and there are other herbicides that attack weeds through this mode of action.

HPPD-resistant soybeans are listed as being in late development stage by Syngenta, according to Ray Riley, head global corn research and development. Late-stage development would indicate an introduction of no more than five years after 2012.

"The HPPD tolerance is a great example of where there has been tremendous interaction between our scientists creating a GM [genetically modified] event, our researchers who look at an integrated solution, customer needs and our crop protection colleagues," Riley said. "We have seen great opportunity going into the future."

Purchases and Partnerships
Bayer CropScience found it advantageous to acquire the start-up company, Athenix, to expand and enrich its research and development related to genetics, and Syngenta isn't contrary to doing the same or partnering with companies. Riley said, "There are a lot of creative minds out there [in genetic research] who will think of things differently, and it is important for us in the industry to make sure we are positioned to be a preferred partner with people who develop that innovation."

BASF has done its partnering outside the U.S. to introduce its first genetically modified soybean variety in Brazil, which is resistant to the company's imidazolinone-based herbicides. BASF partnered with Embrapa, Brazil's state-owned crop research institute. According to BASF spokespersons, these GM beans will not be introduced to the U.S., and whether the agreement with the Brazilians limits transferring the herbicide resistance to U.S. varieties was not disclosed.

DuPont Company scientists were early discoverers of ALS herbicides, and therefore, it is logical that Pioneer, a DuPont Company, is developing crops resistant to ALS herbicides. The company contends its new Optimum GAT trait will "maximize yield by achieving glyphosate and ALS crop safety while protecting yield with better weed control options." The Optimum GAT trait will allow for post-emergence weed control plus residual weed control.
Pioneer has reset its plans to commercialize Optimum GAT in corn and will not have controlled releases in 2010 and 2011 in North America. Pioneer announced it will intensify its ongoing research efforts along "multiple pathways for the corn trait" and will work toward commercialization in the middle of the decade.

Optimum GAT in soybeans is expected to be commercialized about two or three years later than the originally anticipated 2011 introduction "due to changes in regulatory policy in key import markets and increasing complexity in managing grain stewardship," the company also announced.

 As for the original and biggest genetic-focused company in the world, Monsanto has various herbicide-resistant crop projects in the works. As of last year, it began selling the upgrade to Roundup Ready soybeans with its Genuity Roundup Ready 2 Yield version; the company is widely launching the technology this year. Trial work is rapidly progressing on Genuity Roundup Ready 2 canola.

Extensive work is being done in developing crops tolerant to dicamba herbicides of which soybeans, corn and cotton are the only ones being extensively touted at the moment. Cotton that is tolerant of Roundup Ready Flex, dicamba and glufosinate herbicides "represents Monsanto's first three-way stack of herbicide-tolerant technologies," the company points out. The project is in phase three of four phases in the Monsanto pipeline, just ahead of "final pre-launch regulatory submissions, seed bulk-up and pre-marketing."

As for corn tolerance to the same three herbicides, that project is in phase two of development. And in the initial phase of development is corn tolerance to fop herbicides, according to Steve Padgette, vice-president, biotechnology. 

New to the market this year is SmartStax seed corn introduced by Dow AgroSciences and Monsanto, which has glyphosate and glufonsinate herbicide tolerance along with insect resistance.