RE: oxalis, lawns

whoa Jerry you've hit the nail on the head with your complaints
about the universities and the lack of consistency.
Unfortunately information on the internet is only as good as the person who
posts it and universities like most large institutions tend to find heaps of
cash to post lovely web pages outlining the admin areas, new courses,
facilities etc etc all posted by a well paid IT team member hired just to
produce web pages.

But any real useful information is probably posted by a staff member in
thier lunchbreak or after work who has an interest in the area or works in
the area.

Some Oxalis spp. are killed by 2,4-D and others most defineately are not .
Most however are affected by Chlorsulfuron or a combination of Glyphosate
and Chlorsulfuron.  Use carefully as use rates of Chlorsulfuron are very
very low and could kill lawns.  I would only recomend Chlorsulfuron if you
had a very severe Oxalis pes-caprae infestation or one of the other very
tenacious bulbous Oxalis spp. Check with your local Ag department on this.

Jerry has highlighted the problems of not correctly identifying the species
to which you are referring, and all those Universities were in the same
country, imagine the problems people from overseas and non english speaking
countries  would have. 

You've probably heard the saying that "if you give a million monkeys
typewriters you'll eventually end up with a copy of the Complete Works of
Shakespeare" 

I recently heard a nice retort to that, and I agree!
"Well thats  been proven wrong by the internet".


At least we still have groups such as this to keep ourselves informed,
where we can ask questions rather than have to search for answers!

Oh and all the web pages that I've put up over the last few years,
I'm not paid for it...

:-)

Cheers, Rod

~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~
Rod Randall
Weed Risk Assessment
Weed Science Group, Agriculture Western Australia

                 "I weed..." 

Weed Risk Assessment Home Page:
http://www.agric.wa.gov.au/progserv/plants/weeds/weedsci2.htm

Weed List Page:
http://www.agric.wa.gov.au/progserv/plants/weeds/weeds/weedlist.htm

Weed Activity Calender:
http://www.agric.wa.gov.au/progserv/plants/weeds/calendar.htm

WeedBusters Home page:
http://www.agric.wa.gov.au/progserv/plants/weeds/buster/buster.htm

Weed Science Group Home Page:
http://www.agric.wa.gov.au/progserv/plants/weeds/

Plant Protection Society & Western Weeds Homepage:
http://www.wantree.com.au/~weeds/

 ph: 08 9368 3443
fax: 08 9474 3814
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> ----------
> From: 	heverlyj@ccnet.com
> Reply To: 	heverlyj@ccnet.com
> Sent: 	Wednesday, 27 January 1999 3:18 AM
> To: 	medit-plants@ucdavis.edu
> Subject: 	oxalis, lawns
> 
> I've been away two days having my hernia repaired.  I came back to over 50
> messages from this group, alone.  We're cookin.  Since I'm in
> post-operative pain no one is allowed to yell at me about how
> unnecessarily
> long this post is.
> 
> These streams give me a chance to make a confession.  I lurk in this group
> feeling consistently guilty because my interests are in the practicalities
> of horticulture:  fertilizers, pesticides, lawns, etc.  I know that I'm
> supposed to be commenting on Medit plants, their care and appreciation.
> The trouble is I don't know much about that.  I know a lavender from a
> rosemary but I'm in awe when I read the delineations of variations within
> a
> genus or even among cultivars.  My strategy has been to keep quiet within
> the group as much as possible and then to quickly cram in a post from my
> perspective hoping that no one will notice that I'm always violating what
> I
> believe to be the tacit rules of the discussion.
> 
> I'm doubly conflicted because I'm trying to write a book about products
> commonly sold in California nurseries so I'm filled with this kind of
> minutiae and its hard for me to resist boring others with it.
> 
> Re recent posts:
> Botanical names vs. common names:
> I love the fact that I'm taking part in a discussion amongst members from
> Tasmania, Australia, New Zealand, Hawaii, North Carolina, Florida,
> England,
> Scotland, Italy, Greece.  I don't want California to dominate the
> discussion.  I'll gladly try my best to include botanical names in order
> to
> avoid any implication that we're excluding other areas.  I like to
> occasionally boast to the customers at the nursery where I work:  'Ah, we
> were just discussing Monterey Pines on my internet group.  Yes, Moira in
> New Zealand, told us.....'  It's my best chance to be snooty.
> 
> 
> Oxalis:  (Sorry, here comes the herbicide stuff)  You think *we've* got
> problems with Oxalis names.  Try researching herbicide treatments and
> you'll find some of the following:
> 
> The University of Florida, USA, lists O.corniculata and O.pes-caprae on
> it's weed list.  But when the same university cross-references with
> herbicide treatments they suddenly drop any mention of O. and  begin
> talking about 'Smallflower Buttercup'!  Is that an Oxalis?  Who the heck
> knows????  And these guys are scientists.
> 
> The University of California specifies O.corniculata as a common weed.
> OK.
> Then they say that the herbicides that control O.corniculata do not
> control the common weed O.stricta.  But they never specify which
> herbicides
> control which weed.  A fat lot of good that does me.
> 
> Ohio State University lists 'red sorrel' and 'wood sorrel'(Oxalis).  Is
> red
> sorrel an oxalis?  Some of my books list 'Sorrel' as *Rumex scutatus*, a
> totally different weed.
> 
> The University of Maryland eschews botanical names altogether!  They list:
> Oxalis, creeping
> Oxalis, common
> Red Sorrel (*Rumex*?)
> Each of these gets a different herbicide treatment.  How am I supposed to
> decipher this???
> 
> And trying to do a search for Oxalis revealed that different universities
> in the US list Oxalis as:
> 
> Sorrel, red
> Wood sorrel
> Common yellow wood sorrel
> Creeping woodsorrel(Oxalis spp.)!!
> 
> A few even list it under, tadah, Oxalis, except that they mention(without
> much explanation) the following species:
> 
> corniculata
> stricta(southern US says the U.Cal)
> pes-caprae
> forida(U.Fla)
> dillenii
> adenophylla(is this the pink petalled variety mentioned on this group?)
> triangularis
> oregana(an ornamental, is it a weed some places?)
> 
> Now from a practical point of view all the above has much significance.  I
> could ramble on about this for pages but I think I can summarize:
> 
> pre-emergent herbicides prevent O. from growing.  But they don't work on
> the bulbous forms nearly as well as the others.  And their effectiveness
> varies according to soil texture and climate.  Failure to be clear on the
> *botanical* name makes most of the university literature useless to me.
> 
> post-emergent herbicides kill the growing plant.  Some of the universities
> recommend the world's most common herbicide, 2-4-D and its relatives,
> mecoprop and dicamba.  Others(U.Cal) adamantly maintain that O.is
> resistant
> to these herbicides.  But 2-4-D comes in at least 3 distinct forms.  Could
> this be the area of disagreement?  Who knows, the universities don't
> specify the species *or* the kind of 2-4- D they are talking about.
> Again,
> *this makes the info useless to me*.
> 
> One of the 'trick' ways of controlling O. is to adjust soil pH.
> Pes-caprae
> hates a low pH soil.  Oregana loves a low pH.  Better know what species
> you have before you try this one.
> 
> Other trivia:
> Oxalis is from the Greek word for sour, according to the U.Florida
> 
> Post-emergent you can kill it *non-selectively* with glyphosate(aka
> Roundup
> and lots of other names).
> *Selectively* you can kill it in a lawn with a material called triclopyr
> which can be bought from two companies, Monterey and Ortho(in California,
> that is).
> Ammonium thiosulfate is another post-emergent which someone perseptively
> mentioned on this group.  But AT works best only when aerial temperatures
> are above 80 degrees.
> All of the above require repeated treatments.  Don't expect one spraying
> to
> do the job.  The herbicides don't always translocate into the bulblets of
> the bulbous forms and the others reseed every 6 days or so in spring and
> fall.
> 
> You can partially control corniculata *pre-emergently* with materials
> called pendamethalin and isoxaben, both widely available in California
> retail nurseries.
> 
> Rod Randall, if you can correct any mistakes I've made here I'd love it.
> Jerry Heverly, Oakland, CA
> 
> 
> 
> 
>
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