hort.net Seasonal photo, (c) 2006 Christopher P. Lindsey, All Rights Reserved: do not copy
articles | gallery of plants | blog | tech blog | plant profiles | patents | mailing lists | top stories | links | shorturl service | tom clothier's archive0
Gallery of Plants
Tech Blog
Plant Profiles
Mailing Lists
    Search ALL lists
    Search help
    Subscription info
Top Stories
sHORTurl service
Tom Clothier's Archive
 Top Stories
New Trillium species discovered

Disease could hit Britain's trees hard

Ten of the best snowdrop cultivars

Plant protein database helps identify plant gene functions

Dendroclimatologists record history through trees

Potato beetle could be thwarted through gene manipulation

Hawaii expands coffee farm quarantine

Study explains flower petal loss

RSS story archive

Re: round-up pro

Theresa, there is probably some answer available thru UC Davis.

This is one reference I found which lists Devrinol and Treflan for asparagus herbicides, neither of which I have ever heard of.
Good luck,
Barb, Grass Valley CA
----- Original Message ----- From: "Theresa G." <macycat3@sbcglobal.net>
To: <gardenchat@hort.net>
Sent: Friday, May 23, 2008 5:53 PM
Subject: Re: [CHAT] round-up pro

For how long would you keep your vegetables away from it? This is exactly what I'm worried about.

Josh Haskell wrote:
Monsanto's patent on glyphosate expired in 2000, and since then there has
been a lot of competition, with marketing focusing on "faster-acting" and
"stronger" products.  I had always understood that using too high a
concentration would defeat its effectiveness, but manufacturers are now
adding surfactants to speed up the result. Dr Hannah Mathers at Ohio State University has been researching this subject for the past few years. Here
is an excerpt from one of her papers:

Roundup Carryover Injury in Woody Plants: Roundup (glyphosate) has been
labeled foruse in ornamental plantings for over 30 years. It has been
utilized in the nursery and landscape industries extensively due to the
numerous attributes that it possesses. Some of these attributes are: limited
soil activity, non-volatile, broad-spectrum, systemic, low environmental
impact, ability to translocate throughout the plant, ease of use, and low
mammalian toxicity.  Roundup went off of patent in 2000, thus opening the
market to many generic brands of glyphosate.  In 2007, there are 41
different glyphosate products,such as Touchdown, Jury, Cornerstone, Roundup
Original Max, Roundup Pro, Roundup, Weathermax, and others. Each of these
glyphosate products utilizes various surfactants with varying doses.
Consumers tend to want a faster working product, thus the makers of
glyphosate products have incorporated many surfactants to break down the
cuticle of the plant. These products have been sold as providing better weed control - which has not been shown in research and worse if contact is made
with nursery or landscape plants, injury may result.

Research is currently in place at Ohio State University to study different
glyphosate containing products with varying surfactants.

Glyphosate is readily broken down by microbes within the soil and is tightly
bound to clay, hence the limited soil activity. Although glyphosate is
broken down within the soil, once in the phloem of a plant, it may take
years to break down. This is considered a sublethal dose, thus causing
injury to the plant. Absorption of glyphosate is possible with thin barked or bark with pigment (Kuhns 1992). Also, it is not yet known if glyphosate accumulation is possible in mulch, thus contributing to glyphosate injury.
Roundup will have carry over if applied to peat (John Ahrens, personal
communications, 2007) so accumulation in mulch is possible. Injury symptoms
may not be present up to two years after absorption of glyphosate occurs
(Kuhns 1992).

There are several symptoms that will occur when a woody plant is exposed to
a sub-lethal dose of glyphosate. These include: witches broom, stunting,
bark cracking or splitting (Figures 1 and 2), loss of apical dominance,
individual dead limbs (Figure 2) (Mathers 2006), chlorosis, and/or death
(Kuhns 1992) (Ferrell et al. 2006). We speculate that the removal of suckers and adventious shoots, especially with broad spectrum systemic postemergents
(especially new formulations of glyphosate) or shortly after mechanical
removal of suckers may be one reason for the increased severity and
frequency of bark splitting.

If you google "Hannah Mathers" and glyphosate, you will find several
articles. Bottom line: although her research focuses on woody plants, there
is much still unknown about long term effects; I would keep my vegetables
away from it.


----- Original Message ----- From: "Theresa G." <macycat3@sbcglobal.net>
To: <gardenchat@hort.net>
Sent: Thursday, May 22, 2008 9:24 PM
Subject: [CHAT] round-up pro

So- anybody know what the deal is with "Round-up Pro"?  How long does it
take to break down in the soil? Is it safe to plant veggies in that area after you used it- do all the chemicals biodegrade?? Thanks for any help-

To sign-off this list, send email to majordomo@hort.net with the

To sign-off this list, send email to majordomo@hort.net with the

To sign-off this list, send email to majordomo@hort.net with the

To sign-off this list, send email to majordomo@hort.net with the

Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index

 © 1995-2017 Mallorn Computing, Inc.All Rights Reserved.
Our Privacy Statement