I just attended 9 lecture/workshops at our local 2-day Master Gardener's
conference. 8 sessions ranged from merely interesting to fabulously
informative. (We had 10 time slots for a total of 22 lectures so there
almost certainly were good ones I missed.) However, one lecture
presented as a general session with no competing alternatives was so bad
it left a nasty taste in my mouth and clouded the entire conference for
On the positive side, we had a soil microbiologist encourage avoiding
chemical fertilizers. I enjoyed this lecture although I suspect it was
over the head of most master gardeners used to chemical gardening
methodologies. (I sarcastically asked a friend how this speaker got past
our County Agent's pre-screening.)
The one that left me wondering if it the good sessions are worth the
aggravation of attending such conferences was presented under the
innocent title of "Weed Control in Landscapes." It turned out to be a 75
minute commercial for the herbicides, Goal and Visor, whose manufacturer
paid for the research being described.
I suspect our County Agent has a lot in common with my aggressive red
rooster in that when he gets away with unacceptable behavior, he only
gets worse the next time. He (the County Agent, not the rooster) wrote
an offensive piece in a recent Master Gardener newsletter. (I can't lay
my hands on it at the moment, but he associated organic gardening with
old wives tales and, to the best of my memory, stated flat out that soil
cannot be improved as organic proponents claim.) I chose to ignore the
offensive article. As an encore, something on the order of 200 gardeners
in our county were subjected to a 75 minute commercial for landscape
herbicides. I haven't decided how to challenge this, but feel it should
NOT go unchallenged for fear of something even worse in the future.
But if I do challenge this, I need more background on chemical
herbicides (I've never used ANY of them) and "commonly acceptable"
research techniques. Maybe some of you can help me:
In case you're not familiar with "desert landscaping" as commonly
practiced in urban/suburban areas in my state, here is some background
along with my personal observations. Homeowners and businesses concerned
about water conservation (everyone in the desert SHOULD be) often lay
down a layer of herbicide (Roundup is the only one I recall previously
being mentioned in this context) and/or black plastic then cover it with
crushed granite or similar material. Thereafter, instead of mowing
lawns, they fight to kill weeds that come up after each (relatively
infrequent) rain. Although there are usually a few broad leaf weeds,
Bermuda grass is THE most serious problem. I know this from personal
experience in both Phoenix and Tucson. Since many neighbors actually
cultivate this pest, every wind storm brings in more seeds if you are
unfortunate enough to live in an urban environment, which is the only
environment where such landscape methods are common.
Now back to the lecture I'd like to protest: The lecturer dismissed
mechanical weed control and physical barriers like plastic without
elaboration and went directly to describing his research and its results.
They spread a mixture of:
annual bluegrass (Poa annua),
London rocket (Sisymbrium irio),
Russian thistle (Salsola iberica),
Shepardspurse (Capsella bursa-pastoris), and
Little mallow (Malva parliflora)
onto the experimental plot. NOTE: Bermuda grass is conspicuous by its
absence. The procedure for spreading the weed seeds was described in
considerable detail. Next, they sprayed (using carefully calibrated
equipment) the following on test parcels of this plot:
Goal (oxyflurofen) @ 2 quarts/A (1 lb, a.i./A)
Visor (thlazopyr)@ 2 quarts/A (1 lb, a.i./A)
Dimension (dithiopyr) @ 1 quart/A (0.5 lb a.i./A)
Sulflan (oryzalin) @ 4 quarts/A ((0.5 lb a.i./A)
Pendulum (pendimethalin) @ 4.8 quarts/A (4 lb a.i./A)
Control (no herbicide)
NOTE: Roundup is conspicuous in its absence. They then spread about an
inch (he may have said a half inch--it is not spelled out in the handout)
of crushed granite, applied still more weed seed mixture, and watered the
entire plot. Thereafter, water was limited to natural rains.
NOTE: The lecturer made no mention of the parcels being assigned randomly
and also no hint that there were multiple parcels for a given treatment.
This may be significant, especially considering that tiny differences in
elevation in unirrigated desert can make very big differences in the
run-off vs. infiltration of water and thus big differences in resulting
vegetation. How do I know the researchers didn't purposely place their
sponsor's product in higher plots with the control on the lowest corner?
Goal, Visor, and Dimension "provided acceptable weed control of both
cool season broadleaf and grass weeds" for 11 months. Only Goal and
Visor (manufactured by the sponsoring company) "still provided acceptable
pigweed and purslane control" for 17 months. The photos were dramatic
with the weed growth on the control parcel looking nice and green. One
photo, however, did show pocket gopher damage and the speaker said that
none of the herbicides were effective where the soil surface was
Notes at the bottom of the handout included the following:
" - Dimension was applied at a lower rate than Goal or Visor.
- Goal will not provide good weed control in areas where the surface is
disturbed by traffic.
- Visor is not yet registered for landscape weed control."
So, how about it? Can those of you with formal horticultural training
help me shoot holes in this research as it was reported to the Master
Gardeners of my county? Were the amounts applied appropriate? Are
these two herbicides really "superior" killers?
And, for those of you with political savvy, what advice do you have
about how to protest this? I'm thinking about a letter to the County
Agent's superiors (who most likely applaud his efforts, but who maybe
won't like receiving complaint letters) or maybe writing a letter to the
editor of our local newspaper.
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
To Unsubscribe: Email email@example.com with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
To Subscribe to Digest: Email firstname.lastname@example.org with the command
All messages to sanet-mg are archived at:
This archive was generated by hypermail 2b29 : Sun Mar 12 2000 - 14:00:27 EST