Hi I'm Dennis Worwood. I'm the USU Extension Agent in
Emery County. Today we're talking a little bit about Russian Olive control
using the cut-stump method.
Russian Olives are native to Eurasia and they've become a serious pest in
the western United States,
they're very competitive, they're drought tolerant, they're somewhat
salt tolerant, as a legume they can fix atmospheric nitrogen and out compete
some of the native plants.
One big concern we have in this part of the state is that we now have a
biological control for Tamarisk which is another invasive, woody, species, and
with the Tamarisk being suppressed by their biological control, which is
a beetle, the concern is that we're going
to have an explosion of Russian Olives
to take their place.
And so we've been doing research on different methods to control them.
The cut-stump method that we're going to talk about today has some real
advantages. In about 5 years of research what we've is that it doesn't
matter which month of the year we use this method, it's equally effective and so
that's a good thing for someone who has some time in the off season but not during
the growing season when they're trying to put up crops,
they could do some Russian Olive control.
Another nice thing about the cut-stump method is that it uses a very small amount
of herbicide, and the herbicide is applied directly to the stump
very specific, very little danger of damaging non-target plants
and so it has some real advantages.
The biggest disadvantage is it's fairly labor-intensive and with the Russian Olive
the most difficult part of control is getting close enough to the plant
to control it.
They're thorny and they're shrubby and they're messy to work with.
With the cut-stump method basically you come in and you cut the tree off
and then you apply an herbicide, now, it's a mistake to simply cut the tree and
not apply the herbicide because in our trials basically every tree that we have
cut and left untreated has resprouted and in some cases it appears it actually
invigorates the plant.
After a couple of years some of our untreated cut stumps that the trees are
taller than adjacent uncut trees and already have fruit on them so
as one farmer told me, "if I cut the Russian Olive all I do is make it mad"
that's true unless you apply herbicide afterward.
I'm Ron Patterson with Utah State University Extension in Carbon County
we're talking about killing Russian Olive trees and so I'd like to discuss a little
bit about the chemical we use and our application method.
Some of the chemicals that are labeled for stump-- cut-stump type treatment would
be just as effective. We've found with Russian Olive that glyphosate products
round up or kills all high yields, kills all-- there's a number of products that
have the glyphosate in them and that's what we've used. It's been very very
effective. The aquatic label has been just as good as the non-aquatic label so
we have been very successful year-round using glyphosate products to kill
Russian Olives. I'm sure that the Garlan and some of those others were doing some
other trials on those,
we're testing those to see if they're just as effective but we've had year round kill
using 41% undiluted glyphosate in the-- to treat the stumps.
Now our application method is a little bit unique we use a livestock dosage syringe
just set it to 1 milliliter per click and that way I can tell exactly how much I'm
putting on.
It doesn't take very long to do it that way
some people like to do the little spray bottle thing but the accuracy isn't
probably there, you're not sure how much you're putting on
so we put down our chemical with a livestock syring
so if we've got a four inch tree stump I'll put four milliliters of chemical
around the cambium rings, the outside sap rings of the tree.
There's no point in treating in the middle so we'll come in close and take a look
and show how the application method works with using the livestock syringe.
Alright so we see here we've got this tree we just cut down
the growth the food coming from the leaves down to the roots come down through this
layer and the water coming from the roots up to the leaves comes through the xylem
tissue so you've got the phloem and the xylem tissue
the active phloem and xylem tissue is just around the outside of the tree
these inside rings here are basically deadwood so they're not going to
translocate any of the chemical down to the roots where we need to kill
We've got to kill the roots in order to kill the tree
so, we just take the syringe and probably best if you've got a little bit of a high
spot
you start up here and it'll flow down a little bit
you just treat it down and if you have several stems you need to treat each
stem and I just
for the purposes of making sure I get a good kill
that's about 2 milliliters there we've got about a three and a half inch, four,
four inch stump here so I'll put a little bit on that
that soaks in really quick,
it'll go to each one of these multiple stems and treat each one so that they
all get a good treatment. If you don't treat each stem you're very likely to have
we've got all these little ones so I'll just add a little bit on each one of those
otherwise we would have a very-- likely have some suckers come up that we don't
want, we only want to have to do it once.
Now these that are-- kind of got left, we can do kind of a base of bark treatment
but you need to get that onto those just
like you do all the others.
So that's really the application method.
Really quite simple, it goes fairly fast
you just have to kind of keep up with the sawyers and the swampers and everything
so you got a two or three man crew
they can do the sawing and the swamping, otherwise you can high-stump them and
come back a day later cut them, and treat them we've been doing some research on
that and it seems to be just as effective as if you were to cut it and treat it
quickly.
So when we talk about high stumping we're basically just going to cut up higher
and that will allow us then to come back and make another cut down low so we've
got to get through all this brush to get
to the trunk, then we can make another quick cut down low and get everything
cut off and then we can treat down low.
The other option, we're still doing some trials and research whether or not-- how
effective it is to treat the high stump and kill it this way.
If you do that again you'd have to treat each one of those stumps so there's
a lot more that you have to do but this is an option that may work in a fence
line where you can't get down because you've got the wire in the way
you may be able to cut off at the top of the tree
Jury's still out on how effective that is at this point but now we can cut through
cut that down low and treat the stumps so this is what's called "high-stumping"
One of the reasons we've gone to mostly using glyphosate is we've tried some other
products and the soil activity is a critical factor with this kind of stump
treatment. It seems as though if the chemical has some soil activity such
as Imazapir or well the habitat or arsenal which is Imazapir or some other chemical
then we may have some unexpected or unintended consequences.
There's a spot right here behind me. We treated this stump with Habitat
we like the aquatic label on it and everything but this is actually kind of
a leech zone from the canal down and so we've got the leeching and you
can see down where the Habitat has killed the vegetation down below the
treatment from the motion of the water through the soil.
So glyphosate loses all activity when it comes in contact with the soil so
that's why we've kind of stuck with glyphosate we're trying other products
as well but we're really pleased with glyphosate in that it does not have the
soil activity and kill unintended targets.
Here's another good example of what happens when you've got some soil
activity you can see that streak of dead zone right down below the stump.
You also notice that we've cut these fairly high you can grab this with a
piece of equipment and yank it out. These were treated in 2010 so it's
been three years since these were treated. They're dead so you can come back with
some equipment now yank it out and you would not get any sucker growth off
of it so you can cut them up that high and get good kill about 12 to 14 inches
you don't have to cut them off right down to the ground.
This is an example of a Russian Olive tree that was cut and not treated with an
herbicide, and the growth here represents probably one or two season's growth of
suckers and sprouts from the base of the tree. Now this particular tree once it
had resprouted, we came in and treated with a different treatment method which
was basil-bark herbicide application where you take an herbicide like Garlon 4 Ultra
and a crop oil and mix that and spray
just the bottom 12-18 inches of the tree.
You can see that it's very effective on small trees with thin bark.
But you can expect this kind of regrowth if you simply cut a Russian Olive and
don't treat it with something.
So here's an example, this stump right here was treated in January of 2010 so
it's been 3 and a half years. It's
totally dead as opposed to partially dead, no, it's totally dead.
And here we have one behind us, this was a control that was cut down the same day
but no chemical no herbicide treatment so that's just kind of to show you the
difference of what happens between treatment and no treatment.
In summary the cut-stump method is an extremely effective way to control
Russian Olives. One of the very nice things about it is it doesn't matter what
time of the year you do it, it's equally effective during the growing season or
during the dormant season.
Some of the keys I think are getting a
nice clean final cut so that you have a relatively level surface on all of the cut
stems that you're working with, applying the herbicide within a few minutes after
you've cut, and making sure that you get complete coverage of the cambium area
just under the bark around the surface of each stem.
If you do that, our experience has been that you can expect nearly 100% control.
If you try to do-- take shortcuts, cut the trees and not treat them or cut
the trees and not treat within a reasonable amount of time you may
not have the results you want.
But if you've got some Russian Olives that you'd like to get rid of, give the
cut-stump method a consideration because it's been very effective in our
test plots.