In the row-crop business, we tend to think of herbicide resistance as being just a problem in cotton, grains, peanuts and similar crops. But resistance also has become a factor in orchard crops. Here's an overview of the problem in California's Central Valley and recommendations for dealing with it. It comes from David Doll, University of California Cooperative Extension Farm Advisor in Merced County.
As David writes in a late-December posting on his blog, The Almond Doctor, "Since herbicide resistant weeds are becoming more prevalent in the San Joaquin Valley (think Hairy Fleabane, Horseweed/marestail), it is becoming more important for growers to utilize practices that reduce the chance of herbicide resistance."
He also notes: "Glyphosate is one of the most widely used herbicides for this practice, and, until recently, has provided good control."
Showing posts with label glyphosate resistance. Show all posts
Showing posts with label glyphosate resistance. Show all posts
Friday, January 22, 2010
Thursday, January 21, 2010
Georgia study: why glyphosate stewardship fails to gain ground
ShareEditor's Note: The following is from a press release received today from Weed Science, a publication of the Weed Science Society of America. The journal publishes articles on the biology, ecology, physiology, or management and control of weeds. It also focuses on herbicides, growth regulators, and related topics. To learn more about the society, please visit: http://www.wssa.net/
In the southeastern United States , weeds that can tolerate or resist the popular herbicide glyphosate are threatening cotton crops. In the article “Loss of Glyphosate Efficacy: A Changing Weed Spectrum in Georgia Cotton,” (Weed Science Volume 58, Issue 1, 73-79)
Theodore M. Webster and Lynn M. Sosnoskie examine how the use of glyphosate-tolerant cotton (GTC)—created through genetic modification—has affected weed control issues since its introduction in 1997.
The article is featured in the January–February 2010 issue of Weed Science, published by the Weed Science Society of America. As farmers plant more acres of GTC, they are seeing a change in the most prevalent weeds, which now include varieties that tolerate or resist glyphosate.
The two most troublesome weeds in Georgia cotton are:
These weeds typically develop in systems without diverse weed control practices. “The management practices necessary for minimizing the development of herbicide resistance have not been widely implemented,” Webster and Sosnoskie write. They see a need for farmers to work toward greater stewardship, which is the sum of the management decisions and practices used to preserve the utility of a crop trait, and try new or varied weed management strategies that often may be more expensive.
“Agricultural practices aimed at delaying or preventing the development of herbicide resistance are not viewed as being economical in the short term and are not readily used by all growers,” they write. “Because herbicide resistance can spread quickly, indiscriminate use of glyphosate may result in a loss of weed susceptibility for all growers, a tragedy of the commons.” Webster and Sosnoskie identify two reasons why growers are not adopting methods that promote glyphosate stewardship:
The authors outline several possible incentives for cotton farmers, including industry initiatives to promote better glyphosate stewardship and voluntary government farm programs.
However, they say it likely will take a combination of incentives and a move toward new methods to improve weed control.
“Principles of ecological weed management used in conjunction with herbicide-based weed control systems will likely be an important component of future weed management systems,” Webster and Sosnoskie write.
They also identify several areas for future research: how to limit the development of herbicide-resistant and herbicide-tolerant weeds; whether there is a need to limit the use of glyphosate; factors that may improve control and stewardship of herbicide options; how herbicide resistance traits move across the landscape; what factors could be used to determine a species’ risk of developing resistance; and incentives to help improve herbicide stewardship. The full-text article is available at http://www2.allenpress.com/pdf/WEES_58.1_73-79.pdf.
Farmers who use herbicide-tolerant crops face a growing challenge from herbicide-tolerant and herbicide-resistant weeds, which are evolving and spreading across cropland.
In the southeastern United States , weeds that can tolerate or resist the popular herbicide glyphosate are threatening cotton crops. In the article “Loss of Glyphosate Efficacy: A Changing Weed Spectrum in Georgia Cotton,” (Weed Science Volume 58, Issue 1, 73-79)
Theodore M. Webster and Lynn M. Sosnoskie examine how the use of glyphosate-tolerant cotton (GTC)—created through genetic modification—has affected weed control issues since its introduction in 1997.
The article is featured in the January–February 2010 issue of Weed Science, published by the Weed Science Society of America. As farmers plant more acres of GTC, they are seeing a change in the most prevalent weeds, which now include varieties that tolerate or resist glyphosate.
The two most troublesome weeds in Georgia cotton are:
- Benghal dayflower, which is tolerant to glyphosate and many of the herbicides used in agronomic crops.
- Palmer amaranth, which has developed resistance to many classes of herbicides including glyphosate.
These weeds typically develop in systems without diverse weed control practices. “The management practices necessary for minimizing the development of herbicide resistance have not been widely implemented,” Webster and Sosnoskie write. They see a need for farmers to work toward greater stewardship, which is the sum of the management decisions and practices used to preserve the utility of a crop trait, and try new or varied weed management strategies that often may be more expensive.
“Agricultural practices aimed at delaying or preventing the development of herbicide resistance are not viewed as being economical in the short term and are not readily used by all growers,” they write. “Because herbicide resistance can spread quickly, indiscriminate use of glyphosate may result in a loss of weed susceptibility for all growers, a tragedy of the commons.” Webster and Sosnoskie identify two reasons why growers are not adopting methods that promote glyphosate stewardship:
- The belief that a new technology will be developed to solve the resistance and tolerance problems, although no new herbicides have been introduced commercially since 1998
- The belief that resistance management strategies will be futile because most farmers think herbicide resistance traits are mobile through pollen-mediated transfer and their fields are affected by other nearby farms
The authors outline several possible incentives for cotton farmers, including industry initiatives to promote better glyphosate stewardship and voluntary government farm programs.
However, they say it likely will take a combination of incentives and a move toward new methods to improve weed control.
“Principles of ecological weed management used in conjunction with herbicide-based weed control systems will likely be an important component of future weed management systems,” Webster and Sosnoskie write.
They also identify several areas for future research: how to limit the development of herbicide-resistant and herbicide-tolerant weeds; whether there is a need to limit the use of glyphosate; factors that may improve control and stewardship of herbicide options; how herbicide resistance traits move across the landscape; what factors could be used to determine a species’ risk of developing resistance; and incentives to help improve herbicide stewardship. The full-text article is available at http://www2.allenpress.com/pdf/WEES_58.1_73-79.pdf.
Tuesday, January 19, 2010
Top 10 Questions And Answers About Liberty-Link Soybeans And The Fit With Roundup Resistance
Two Georgia Extension workers released a white paper this month on where, generally speaking, Liberty-Link (LL) soybeans will fit in that state, especially from the standpoint of dealing with Roundup-resistant pigweed, which probably rates now as that state's number one agronomic problem in field crops.
Nobody is saying that LL beans are a silver bullet, and the report delves into some limitations with the system. But the paper does examine the parameters of the technology. It was written by Jared R. Whitaker (Extension Agronomist – Soybean and Cotton) and Eric P. Prostko (Extension Agronomist – Weed Science).
Here's a link to their report.
Nobody is saying that LL beans are a silver bullet, and the report delves into some limitations with the system. But the paper does examine the parameters of the technology. It was written by Jared R. Whitaker (Extension Agronomist – Soybean and Cotton) and Eric P. Prostko (Extension Agronomist – Weed Science).
Here's a link to their report.
Subscribe to:
Posts (Atom)
