Paraquat burns down difficult weeds in USA
Over the years in many areas of the United States, certain weeds have become resistant to some herbicides used, most recently to glyphosate since Roundup Ready crops have been grown on an increasing massive scale.
Horseweed / marestail (Conyza canadensis) is native to the United States, but it has recently become much more problematic to control in Roundup Ready soybean production. Horseweed is well adapted to no-tillDescription Also known as conservation tillage or zero tillage is a way of growing crops from year to year without disturbing the soil through tillage ie cultivating the soil usually with tractor-drawn implements. Authoritative On-line References and Resources http://www.no-till.com/index.htm A portal for on-line information about no-till farming. crop production. It has developed resistance to several herbicides including glyphosate (resistance maps on weedscience.com ). Horseweed was the first broadleaved weedDescription The leaves are "broad" as opposed to the "narrow" leaves of grasses. Also called 'dicots' having two seed leaves, while grasses are 'monocots' having one seed leaf. Authoritative On-line References and Resources http://iws.ucdavis.edu/ The International Weed Science Society represents individual associations around the world. Details of these regional associations are listed. documented to develop resistance to glyphosate in the United States. Since this initial report, glyphosate resistance has been reported in several other states.
Dr L. Steckel is a row-crop weed specialist in Tennessee, USA. He has statewide extension responsibility as a weed specialist for all row cropsDescription Annual crops traditionally grown in wide rows such as corn, soybeans and cotton. Authoritative On-line References and Resources http://www.ncga.com/index.asp http://www.soygrowers.com/ http://www.cotton.org/index.cfm The US national associations for those involved in the production of, and trade in, corn, soybeans and cotton.. His research programme focuses upon the study of the biology and management of weeds that are troublesome to Tennessee row crop producers.
He already alerted about horseweed and palmer pigweed (Amaranthus palmeri) resistance in 2006 in an article published by Delta Farmpress.
Weeds and (possibly resistant) volunteers can be eliminated. Weed growth robs valuable moisture that could be used by next year’s crop. Gramoxone Inteon®, a paraquat-based weedkiller marketed by Syngenta in the USA, is used as a tool for resistance management.
In a recent statement he affirms that paraquat is an essential tool in Tennessee’s no-till cotton and soybean production systems:
“Growers not long ago relied almost exclusively on glyphosate to burndown winter annual weedsDefinition Weeds that complete their life cycle within one growing season, or year. From seed to flowering to seed before the year ends. Authoritative On-line References and Resources http://iws.ucdavis.edu/ The International Weed Science Society represents individual associations around the world. Details of these regional associations are listed. before planting cotton or soybeans. That changed in 2001 when glyphosate-resistant horseweed (marestail) started becoming a widespread problem.”
Dr Steckel continues: “Gramoxone Inteon tank mixed with other herbicides will control glyphosate-resistant horseweed and most other winter annuals. In Tennessee, annual blue grass (Poa annua) can be a real problem as few herbicides will readily control it before planting. Gramoxone Inteon will provide very effective control of this troublesome winter annual weed. Gramoxone Inteon also makes a very good early season burndown herbicide as it still works when temperatures are cold. This is not the case for some other burndown herbicides.”
Trent Funk from Elkville (Illinois) mixed Gramoxone Inteon with other herbicides and observed good results in soybean: “This is my first year using Gramoxone Inteon™ on my soybean fields. In the past we used glyphosate, but weren’t able to kill tough weeds like marestail. This year we added 2, 4-D to the Gramoxone Inteon and sprayed our fields at least two weeks before we ever thought about planting soybeans. I’m satisfied overall – it looks like we had good control.”
In Kentucky, 2 farmers also encountered problems with resistant weeds and found Gramoxone Inteon to be a good solution.
Davie Stephens from Wingo (Kentucky) had a similar experience: “I used Gramoxone Inteon™ mixed with a little bit of 2, 4-D on 2,600 acres (1050 hectares) of corn and 120 acres (50 hectares) of soybeans for burndown this year. I’ve been using it to get rid of hard weeds such as marestail that are becoming resistant to an all-glyphosate program. I think with all the glyphosate that is being used right now it’s important to break up chemistries and use Gramoxone Inteon instead of glyphosate. I want to rotate out of weeds building up resistance. I had to replant some of my corn, but because it was GT corn, I couldn’t use glyphosate to burndown. I used Gramoxone Inteon and metribuzin and it worked really well. I always have a good experience with Gramoxone Inteon.”
Jerry Griffith from Mayfield (Kentucky) even ‘repaired’ a damaged crop with Gramoxone Inteon: “We planted glyphosate-tolerant corn this year and some of it froze early in the season. We wanted to replant with more GT corn but didn’t want to harm the corn plants that were not affected by the freeze. My dealer suggested I put something else with the Gramoxone Inteon™, but I didn’t want to bother the germ on the already planted corn. I knew the Gramoxone Inteon wouldn’t bother the germ, so I decide to go without any additional product. It did a good job. The good thing about Gramoxone Inteon is that it will take care of what you don’t want in the field and leave what you do want. Although I hope we never have the freezing problem again, I know I have a solid solution if I go with Gramoxone Inteon. I wouldn’t hesitate to do it again.”
An interactive map shows the state of resistance in the USA for each state with a list of technical contacts for further information on the subject.
Read about the other benefits of paraquat, active ingredient to Gramoxone Inteon here.
Gramoxone Inteon™ and the Syngenta logo are trademarks of a Syngenta Group Company. Gramoxone Inteon is a Restricted Use Pesticide.