Excerpt:
If the presence of surviving waterhemp and horseweed/marestail is more
widespread, a trip back in time using a cultivator is really the only option
to reduce the problems with these escapes.
In a message dated 7/24/2011 10:00:22 A.M. Central Daylight Time,
[log in to unmask] writes:
This is just out from Iowa State University weed scientists. Apparently
the best option they can come up with for controlling glyphosate-resistant
weeds is cultivation.
Ah -- the same conclusion some of us came to a LONG time ago...
Managing Glyphosate Failures
By Bob Hartzler and Mike Owen, Department of Agronomy, Iowa State
University
In the past week we have received numerous calls from farmers, agchem
dealers and industry representatives regarding waterhemp and
horseweed/marestail surviving glyphosate applications made in late June and early July.
Although there are numerous reasons why a herbicide application might fail at
controlling weeds, we are certain that a significant percentage of these
failures are due to the presence of glyphosate-resistant biotypes in the field.
The common question is what can be done to rescue the situation in the
field. Unfortunately, at this time of the year there are few options.
If glyphosate failed earlier to control the weeds, it is unlikely that a
repeat application will do any good in controlling the surviving weeds. The
PPO inhibitors (Reflex, Cobra, Phoenix, UltraBlazer, etc.) are the other
postemergence option available for waterhemp in soybean.
However, the label restrictions regarding weed size are long past and thus
these herbicides are unlikely to provide affective control. There also is
a potential for serious crop injury with the high temperature forecast for
the coming week. Furthermore, the harvest interval restrictions for each
of these products should be reviewed.
Although not popular with the majority of growers, mechanical control is
really the only available option to manage escaped and/or
herbicide-resistant waterhemp and horseweed/marestail at this time. If only scattered plants
are present in the field, hand-weeding the field would be worth the effort
since this will slow the establishment and spread of resistance within the
field. If the presence of surviving waterhemp and horseweed/marestail is
more widespread, a trip back in time using a cultivator is really the only
option to reduce the problems with these escapes.
Bob Hartzler and Micheal Owen are professors of agronomy and weed science
extension specialists with responsibilities in weed management and
herbicide use.
____________________________________
From: Biotech Forum [mailto:[log in to unmask]]
On Behalf Of Laurel Hopwood
Sent: Monday, July 18, 2011 9:40 AM
To: [log in to unmask]
Subject: Resistant weeds leave farmers desperate
http://www.stltoday.com/business/local/article_f01139be-ace0-502b-944a-0c534
b70511c.html#ixzz1SNadASFT
Resistant weeds leave farmers desperate
St Louis Today, July 17 2011
by Georgina Gustin
EDITED
Weeds are becoming increasingly resistant to Monsanto's Roundup forcing
farmers to use other herbicides or multiple modes of action. But farmers are
finding that these other modes of action aren't working either - and there
appears to be little relief on the horizon. Farmers are also frustrated
because these additional herbicides are costing them profits.
Critics of the industry point out that Monsanto and its competitors have
known about glyphosate resistance.
Brett Lorenzen, a legal analyst with the Environmental Working Group,
stated "It's hard to read a 54-page booklet."
Laurel writes:
Monsanto apparently had an aggressive PR campaign to convince farmers that
GM crops would make it easier and cheaper to farm. It's unfortunate that
farmers are now seeing the truth and are apparently having a difficult time
purchasing non GM crops.
The quote about the 54 page booklet being "hard to read" is very telling.
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