Hi, everyone.
My name is Paul Harris.
I'm a research technician for the Center for Water, Fish,
and Landscaping, and we're going to do our best
to try to show you grass.
So right here, we're on our NTEP putting green,
and this is where at the end of a five-year study where
we've looked at about 20 different varieties of creeping
bentgrass.
And we've monitored these grasses in typical, not
high water use, but standard water use as well as low water
use.
So if you were here in person, you
could walk through and easily tell which one is which.
We see a lot of localized dry spots in this low irrigation
whereas, the other half is typical irrigation.
And over the course of this study,
we've collected data on visual quality, genetic color,
those sort of things.
And so there's two treatments with this study.
We're looking at low-water applications
and typical irrigation applications.
And for the most part during the study,
we didn't see a whole lot of difference between the two
applications.
We concluded that you can effectively
maintain creeping bentgrass putting greens
with about 60% ET replacement.
And what that means is the evapotranspiration that
occurs throughout the day, say we need
to replace one inch of water, which is a lot,
we only need to replace 60% of that or 6/10 of an inch.
So that's what 60% replacement means.
And like I said, we didn't see a whole lot
of differences between the two water treatments
until there was some sort of irrigation
dry down or something happened where
we weren't able to deliver irrigation properly.
And usually that happens when we see like a clogged filter
in our system.
And so the sprinklers won't run at full capacity.
Or we have a really windy night, so there's a lot of drift
and the water doesn't hit its target like it typically does.
In that case, the low-water treatments
had a longer recovery time.
And because it's science and we can't baby this
like we typically would, a putting green on the golf
course, we just have to let it die
and then struggle to let it survive I guess.
So thus, the biggest difference between the two treatments
is the recovery period whenever we
did see some sort of dry down event
or we had some localized dry spot appear.
As far as spring green up, they were both about the same.
They both came out of dormancy at the same time.
And usually once cooler temperatures
arrived in the fall in September, October,
we would notice that the low-water use
treatment would catch up to the typical water-use treatment.
One of the observations that we noticed
is just amongst the different cultivars of the creeping
bentgrass is we have a lot of varieties
that are what they call in the industry as improved varieties.
So they're bred to have a tighter
canopy so you have less disruption I
guess as the ball rolls.
But those varieties also tend to be a little bit more thatchy.
And what we've noticed is these more thatchy varieties,
they would be most likely to develop these localized dry
spots or hydrophobic areas.
And you can tell--
we had a dry down event a couple of weeks
ago where there's a glitch with the irrigation system
and we weren't able to irrigate, and you could almost
tell exactly which varieties were affected the most by it.
And if you were with me, you could come through and step
on each one of the varieties, you
can tell which ones are spongy, what we'd call it,
and other ones that are a little bit more firm.
And we found that the older varieties that have been around
for decades were the ones that were least susceptible
for localized dry spot.
They were least thatchy.
Even they weren't the prettiest, but they still
were able to avoid too many dead spots
from these dry down events.
One thing I do want to point out just the nature of this study.
In our other studies, we'll go through
and we'll actually kill the edges of the plots
with roundup.
So we can keep them from expanding into the other plots.
But these ones we put nails in the ground and that
just helps us identify where one variety stops and the other
begins.
And over the time, we've noticed that the ones
that are a little bit--
the least competitive ones will actually shrink.
You can see that--
well, I don't know if you can see.
I've been looking at this for the last five years.
But this one's kind of bled into this plot a little bit.
This one of the older varieties is not as competitive,
and we're seeing it start to shrink.
And over the course of maybe 10 or 15 years,
that probably disappeared altogether.
And if you're on older golf course,
you might see something similar where
you see patches of different colors of bentgrass.
That's what's happening in those areas.
So it's been a fun study to work on although it is very time
consuming.
I'm excited to spray with roundup tomorrow.