On 30 Apr 2008 20:55:42 GMT, Steve wrote:

wrote:
Steve said:

KC wrote:
On Apr 23, 7:11=A0pm, Eggs Zachtly wrote:
Chas Hurst said:

Is there a selective herbicide that controls annual bluegrass
growing in=

perenial bluegrass?

Not that I've ever heard of. I called a spray tech from work, and he
said the same thing.
--

Eggs

-Opportunities always look bigger going than coming.

I don't have any experience with bluegrass, but I have to ask the
question anyway: If annual bluegrass comes back every year from seed,
why wouldn't a preemergence control it without harming the perennial?

KC

Pre-e will help somewhat but timing is everything. I use it in August
for poa control here in northern Ohio. You have to be careful to stay
away from bentgrass with it, and not to apply too much for fear of root
pruning on your desirable turfgrass.

You have to apply it after the poa dies back and before it
re-germinates, which is generally late summer.

Which then leaves the dillema that you then can't reseed the perennial
bluegrass, in the fall. The pre-emergent doesn't care who's seed is
trying to poke through the barrier.

Poa annua sucks. I can't imagine trying to rid it from a lawn of P.
pratensis. They're the same genus. Even /if/ such a selective herbicide
were available, being species-specific would put it well out of reach of
a homeowner, both in cost as well as by government regulations.

Yep, between a rock and a hard place to control it, I've heard guys trying
growth regulator on it with some limited success too. One of these days a
better control will be available and the cash cow will come home to someone
like Monsanto or Dow or who knows who..



Some info that I have found but have not tried (two snippets). You
may be able to google and find it also.
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Poa Annua-
Is it yellowish-green? Does it die out under drought conditions? Then
it's probably poa annua, or annual bluegrass. If so, then your
gardener is on target -- control is very difficult -- but not
impossible. Some folks have success with preemergence herbicides
(such as Scott's Turfbuilder Halts Plus for crabgrass control), but
the application must be timed right; it's probably already too late to
do anything about it this year. There is a postemergence product that
has been on the market for a couple of years called ethofumesate
(tradename Prograss) that is very effective. However, it is
available only to professionals; it might not even be authorized for
use on residential lawns.
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Abstract: The postemergence herbicide ethofumesate and the plant
growth regulator paclobutrazol were evaluated for annual bluegrass
control in creeping bentgrass turf managed as golf fairways. Both
products were applied under several different timing regimes relative
to the time of the year. Paclobutrazol treatments provided
significantly greater annual bluegrass control than ethofumesate.
There were no differences between rates of paclobutrazol (0.28 and
0.14 kg ai/ha) when applied from spring through summer. Annual
bluegrass control after spring and summer applications of
paclobutrazol was 85% or more. Clipping weight data indicated that
paclobutrazol suppressed growth in annual bluegrass longer than in
creeping bentgrass. It was concluded that prolonged suppression of
annual bluegrass by paclobutrazol resulted in creeping bentgrass
dominance and subsequent annual bluegrass control. Additionally,
applications of ethofumesate in autumn–winter, followed by
paclobutrazol applied in spring–summer, provided significant control
of annual bluegrass in 1 yr of the study.

Nomenclatu Ethofumesate; paclobutrazol,
(±)-(R*R*)-ß-([4-chlorophenyl]-methyl)-a-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol;
annual bluegrass, Poa annua spp. annua L., spp. reptans Hausskn. #3
POAAN; creeping bentgrass Agrostis stolonifera L. ‘Penncross’,
‘Providence’.
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