THE OHIO TURFGRASS FOUNDATION MAGAZINE | MARCH

THE OHIO TURFGRASS FOUNDATION MAGAZINE | MARCH/APRIL 2010 | Vol. 72, No. 2
Contents
TURF NEWS | THE OHIO TURFGRASS FOUNDATION MAGAZINE | MARCH/APRIL 2010 | Vol. 72, No. 2
FEATURES
8
Cover Story
Season-Long Caterpillar Control…
Fact or Fiction?
14
Sports Turf Tips
Seed to Play in 4 Weeks!
18
Lawncare Tips
Controlling Lawn Insects
without Pesticides…
Part One — Cultural Controls
22
Golf Course Tips
Managing Naturalized Areas
on Golf Courses…
Maintenance Tips to Keep
Weeds at Bay and Balls in Play
28
Turf Talk
Identification and Control of
Late Winter/Early Spring
Weeds in Turfgrass
DEPARTMENTS
4
TURF N E W S • March/April 2010
6
President’s Message
30
OSU Turf Science Team
7
News from OTF
30
Index of Advertisers
30
Calendar of Events
31
OTF Membership Application
Continued •
M E S S AG E F R O M T H E P R E S I D E N T
The Ohio Turfgrass Foundation
1100-H Brandywine Blvd.,
Zanesville, Ohio 43701-7303
1-888-OTF-3445
www.OhioTurfgrass.org
Turf News distributes useful and timely advice,
information and research from Ohio’s most knowledgeable experts and professionals to OTF members and those in the turfgrass industry.
Publisher
Leading Edge Communications, LLC
206 Bridge St. | Franklin, TN 37064
Phone: (615) 790-3718 | Fax: (615) 794-4524
info@leadingedgecommunications.com
OTF Officers
President
Joe Enciso
Midwest Turf Consultants
Hilliard, OH
Vice President
Doug Gallant
The Cincinnati Reds
Cincinnati, OH
Treasurer
Kim Kellogg
Grasshopper Prop. Maint.
Millersburg, OH
Past President
Dan Walter
Blue Ash Golf Course
Blue Ash, OH
Trustees
Mike Dietrich
John Deere Landscapes
Huron, OH
Jim Dillard
Century Equipment
Toledo, OH
Todd Dodge
Brown’s Run Country Club
Middletown, OH
Kyle Frederick
Rattlesnake Ridge G.C.
Sunbury, OH
Ryan Gregoire
Agricultural Design, Inc.
Westfield Center, OH
Don Lawrence
Midwest Turf
Worthington, OH
Jason Straka
Hurdzan/Fry
Columbus, OH
Executive Director
Kevin Thompson
Offinger Management Co.
Zanesville, OH | (888) 683-3445, ext. 3151
kthompson@offinger.com
Director of Education
John Street, Ph.D.
The Ohio State University
Columbus, OH | (614) 292-9091
street.1@osu.edu
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
5
M E S S AG E F R O M T H E P R E S I D E N T
Joe Enciso
2010 OTF President
WIIFM…
What’s In It For Me?
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
WIIFM… argh, not another acronym! I learned
this one a while ago in a sales seminar that had
me (a sales professional) answering customers’
questions like, “Why would I buy your product?”
In other words, “What’s In It For Me?” Seems
kind of selfish at first sound, but if you will allow
me to dig a little deeper, I think this applies to
the current times, as we look at how we (your
officers and board of trustees) make OTF a
foundation that truly serves its members.
As your current OTF president, I find that
the answer to that question is pretty simple for
me. It is personally and professionally rewarding
to be involved with an organization whose sole
purpose is to give back to the industry I choose
to make my living in. It seems like a way of paying forward (Wayne Woodrow Hayes).
If you’re an OTF member, WIIFM? Each of
you has to figure this one out for yourself. If
you take a few minutes, the answer will be (we
hope) the value you get from your membership
— the educational events held and sponsored by
OTF, the Annual Conference & Show, Spring
Tee Off, regional seminars, OSU Field Days,
articles in our magazine and more. Also, the networking that comes whenever we get together is
probably the most valuable time any of us spend.
A single idea gained from a fellow member could
change the way you manage a situation.
I also believe that you will “get out” of anything you do that which you “put in.” Sometimes
you get back many times over. If you have the
chance to support an OTF event, please do your
best to do so. If you go and interact with the
6
TURF N E W S • March/April 2010
other members of our organization, you will be
paid back for your time spent. It is also noticed
and appreciated by the other members.
So go ahead and ask — what’s in it for me?
Come up with your answer. OTF needs our
members to be engaged by giving us your needs
and advice to assist us with the stewardship of
OTF. You have a board that is diverse and excited
about the future of OTF.
For prospective members, WIIFM? The benefits are the same as any existing member. The
question, though, still must be answered individually. I believe that we are currently reaching half
of our current golf operations and less than 10%
of our sports and municipal operations. This also
does not include the lawn care industry. These
are groups that either have not been exposed to
OTF or have decided not to join. With some
research, we know that most have not been
exposed to OTF. It is our job to make sure that
every non-member, at a minimum is exposed to
OTF so they can decide WIIFM!
I would like to thank our immediate past
president, Dan Walter, for his time and effort
over the past year. He will be missed as president,
but he is still very involved as past president.
Please keep in your thoughts and prayers the
members who have passed away over the past
year and their families.
Respectfully yours,
Joe Enciso
2010 OTF President
N E W S F R O M OT F
Don’t Let Your
MEMBER BENEFITS EXPIRE!
It’s
time to renew your membership to OTF (unless, of
course, you’ve already done so!). OTF membership
runs from February 1 through January 31, and renewal
invoices for 2010 have already been mailed out.
Please renew your membership immediately. If OTF does not receive
your renewal before May 1, valuable member services and benefits —
including our new and improved Ohio Turf News magazine — will expire.
If you did not receive your renewal invoice, or if you have questions
about your membership, please call OTF at 888-683-3445. Also, if you
have a co-worker or professional acquaintance who is interested in joining
OTF, feel free to copy the Membership Application form on the inside
back cover of this issue. Dues and the OTF mailing address (for sending
in the application) are all conveniently on the application. The Ohio Tur fgrass Foundation Magazine • TURF N E W S
7
C OV E R S TO RY
8
TURF N E W S • March/April 2010
By David J. Shetlar, Ph.D., Professor of Urban Landscape Entomology,
The Ohio State University, OSU Extension & OARDC
G
olf course superintendents
have continually struggled to
deal with cutworms, armyworms and sod webworms on their
short-cut putting greens and tees. Most
cool-season zones have five to six common species of these caterpillars. Each
caterpillar species has a different life
cycle strategy, which can make it appear
that there is no time that greens and
tees can be completely protected from
their attack!
This has been especially true when
our primary caterpillar-killing insecticides (e.g., pyrethroids, Dursban, Sevin,
Conserve and Provaunt) have relatively
short residual activities of 7 to 20 days.
And, the new neonicotinoids (e.g.,
Merit, Meridian and Arena) either have
no activity on caterpillars or, at best,
only short action. In years where caterpillar pressure is high, this often causes
superintendents to apply an insecticide
every three weeks to protect the surfaces.
In this article, the life cycles and habits of these caterpillars will be fully discussed so that you can better target the
times that will control the maximum
number of caterpillars for the longest
period. The new insecticide, Acelepryn,
has been found to be a superior caterpillar insecticide, with a single application eliminating virtually all caterpillar
activities for several months, basically
for the entire season! Timing of application and rates are keys to achieving
this level of season-long control.
The caterpillar complex
In Ohio, as well as most surrounding
cool-season turf states, three types of
caterpillars cause most of the problems on putting greens and tees —
black cutworm, fall armyworm and
sod webworm.
Both the black cutworm and fall
armyworm are semi-tropical species
that cannot survive our low winter
extremes. The common armyworm
(which is in a different genus than the
fall armyworm) does survive in northern states, but this species rarely causes
problems on greens.
About a dozen species of cool-season
sod webworms infest turf, but only
about three of these commonly show
up on golf greens and tees. These
sod webworms break down into two
groups, single generation per year and
multiple generations per year, though
all overwinter as partially mature larvae.
Black cutworms and fall armyworms
can be very mobile caterpillars. They
often stay in one spot for several nights,
and then wander off in search of a new
place to burrow into the soil or thatch
to feed on surrounding grass blades. Sod
webworms are much more sedentary.
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
9
C OV E R S TO RY
•
Continued
Black cutworm life stages: egg, larval instars, pupa and adult.
Once a caterpillar finds a suitable place
to feed, it constructs a permanent, silklined burrow into the soil and thatch.
From this burrow, the caterpillars extend
their bodies out at night to feed on
grass blades.
Black cutworms
Dr. Chris Williamson (University of
Wisconsin) has illuminated the life history of black cutworms in turf more
than any other scientist. From midMarch through early May, black cutworm adults (moths) often ride storm
fronts from Gulf States to Ohio and
surrounding states. Upon arrival, these
adults feed on nectar from flowers and
quickly seek places to lay eggs. They
may infest field crops, especially corn,
or turf. In field crops, the adults lay
clusters of eggs on broadleaf weeds, but
in turf, the female moth attaches single
eggs to the tips of grass blades.
It appears that most of the adults
that arrive in March and early April
produce larvae in turf that most likely
get killed by late freezes, but by late
April, the soil has warmed sufficiently
for larvae to survive. Since it usually
takes about 50 to 60 days for the caterpillars to complete their development;
this means that large black cutworms
can be found in late May into mid-
10
TURF N E W S • March/April 2010
June. Therefore, if a golf course superintendent claims that he has cutworm
damage in early to mid-May, it is most
likely activity from sod webworms,
not cutworms!
Mature black cutworm larvae pupate
in the upper soil/lower thatch zone, and
adults emerge 10 to 14 days later. These
adults mate, feed on flower nectar and
begin a second generation. This second generation of larvae often appear
on golf greens and tees in mid-July
through August.
Strangely, there is rarely a third generation of black cutworm larvae in coolseason turf. We’re not sure where the
adult moths that emerge in August go,
but they rarely lay eggs in turf. However,
the fall armyworm does lay eggs on turf
in August, and since their activities and
feeding damage are nearly identical to
the black cutworm, this pest is often
mistaken for cutworms.
Williamson studied other important
activities of the black cutworm. Since
the eggs are usually attached to grass
blade tips, most are mowed off the
morning after being laid. He found out
that over 90% of the eggs are removed,
and over 80% of these survive this
treatment. So, where do they go? You
guessed it — in the clipping pile adjacent to the greens and tees!
When black cutworm larvae emerge,
they feed on grass blade surfaces. This
feeding is done primarily at night, and
the larvae hide in the upper thatch during the day. For the first three instars,
the larvae leave each other alone, and
they are content in just munching grass
leaves. However, when they reach the
fourth instar (about 5/8" to 3/4" long),
they become aggressive and cannibalistic
— if a large larva runs into a smaller
larva, the smaller one often gets eaten.
Because of this behavior, the fourth
instar larvae begin to disperse from
areas of high numbers to areas of lower
numbers. Larger black cutworm larvae
can easily crawl 50 to 100 feet in a
night before settling down in a temporary burrow.
Once settled, the larva feeds for one
to several days on the grass blades surrounding the burrow. On short-cut
surfaces, this produces the characteristic
“pock-marks” or sunken areas. In the
high-cut turf of fairways, surrounds
and roughs, cutworm-feeding damage
is rarely visible. Thus, it is the damage
on short-cut surfaces that cannot be
tolerated by a superintendent. This
also helps explain why a green or tee
can be treated today, and in 10 to 14
days (after the insecticide residues have
disappeared), the cutworms are back
Continued •
C OV E R S TO RY
again. In actually, the insecticide killed
the ones that were on the green, but
cutworms in surrounding turf move
back onto the surface.
Fall armyworm
Fall armyworms arrive later in the season. Adults often are first detected in
late May into mid-June. This is about
the time that corn is getting large
enough to be an attractive crop, and it
appears that most of the eggs are laid
on this crop. This first generation finishes its development by late July, and
the summer generation of adults commonly lay eggs on corn ears, but they
will also lay eggs around turf.
Fall armyworms lay masses of eggs,
usually on broad, flat leaf surfaces. This
means that in turf, the eggs are usually
laid on greens flags, tree leaves that overhang turf and on other structures (e.g.,
greens markers, cart-path ropes, ballcleaning stands, etc.). Upon hatching,
the larvae drop to the turf where they
feed on grass blades.
While fall armyworm larvae are
rarely aggressive or cannibalistic, they
are active crawlers, especially as larger
larvae. When there are large numbers,
they can mow down the turf or thin it
out so that it looks like summer drought
stress or some leaf-thinning disease. On
greens and tees, the larger larvae make
temporary burrows from which to feed
on surrounding grass blades. This also
causes pockmarks. These larvae can rapidly invade a green or tee 10 to 14 days
after a surface insecticide application
has been made.
Black cutworm or
fall armyworm?
Black cutworm larvae are usually a dark
olive-green color with a broad, lighter
stripe down the back. The head capsule
is a dark, mottled brown.
At right: Top – These “pockmarks” in
short-cut bent were made by a black
cutworm larva, but the fall webworm can
make the same marks. Middle – Mature
fall armyworm larva, showing distinctive
stripe and inverted Y-mark on head.
Bottom – Fall armyworm egg mass
on tree leaf overhanging turf.
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
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C OV E R S TO RY
•
Continued
worm larvae. This foraging by birds is
often mistaken for cutworm searching.
All sod webworm species overwinter
as partially mature larvae within silklined chambers in the soil. In May, these
larvae finish feeding (and leaving marks
on the surface), pupate and emerge as
adults, usually in early to mid-June.
These adults mate in the first day of
emergence and lay eggs by merely dropping them into the turf canopy at night.
Egg-laying is usually finished in three
to seven days. These summer-generation larvae usually finish development
by mid- to late July, and the second
flush of adults fly in August. The larvae
produced by these adults usually overwinter, but in long summers, a partial
third flush of adults can occur in September into early October.
Sampling caterpillars
Typical sod webworm larva and green frass pellets (in high-cut turf).
Armyworm larvae have distinctive
stripes, usually with a white to creamcolored stripe down each side. Fall
armyworm larvae usually have a nearly
black head with a white, inverted Yshaped mark.
Both species will make pockmarks,
and both will come to the surface rapidly when the turf is flushed with soapy
water (see below).
Sod webworms
Adult sod webworms are commonly
called lawn moths or snout moths; these
are the tiny moths that constantly pop
up and fly in front of carts or mowers
during the summer months. They are
brown, tan or gray in color, and different species can have accent markings
of black, white or gold on the wings.
They roll the wings around the body,
12
TURF N E W S • March/April 2010
and the head sports a distinctive snout.
Sod webworm larvae are usually
small (1" long or shorter), light colored
(cream, tan or slightly greenish from
consumed food showing through the
body) and typically covered with rows
of dark, squared spots. Most also have
a light-brown head capsule with no
distinctive markings.
Sod webworm larvae make permanent, silk-lined burrows that extend
from the soil to the turf surface. On
putting greens, these silk borrows run
laterally, just below the mow line, and
they appear as light-brown crescent
marks or streaks that are usually no
more than 1/2" to 1" in length. These
marks don’t interfere with ball roll, but
foraging birds know that there may be a
“treat” below, and they are likely to pull
up tufts of turf in search of the sod web-
While the pockmarks from cutworms
and fall armyworms are pretty easy to
spot, the more subtle damage caused by
sod webworms can go unnoticed until
birds forage. For this reason, I often
recommend flushing with a detergent
solution in May, early July and September to determine if you have sufficient
sod webworms to warrant an insecticide application.
Simply mix two tablespoons of Joy
Ultra, Dawn Ultra or Ivory Clear in two
gallons of water (a standard bucket), and
pour this mix over an approximate
one-square-yard area of turf. Cutworms
and armyworms come to the surface
within minutes, as do earthworms,
spiders, ground beetles and black turfgrass ataenius adults.
Mark the corners where you flushed,
and recheck the spot in 15 minutes,
as sod webworms often take 15 to 20
minutes to surface. It has been our experience that if you get 10 to 15 sod webworm larvae per flushing, you are at
high risk of being hit by foraging birds!
Controls
The standard insecticides that have been
used for years to quickly knock down
caterpillars on greens and tees are still
very effective. Chlorpyrifos (watch
your annual limits!), carbaryl and the
pyrethroids (beta-cyfluthrin, bifenthrin,
cyfluthrin, deltamethrin, and lambdacyhalothrin) at their lower rates have
Continued •
C OV E R S TO RY
been excellent performers. The new
Provaunt insecticide has also been
yielding excellent results.
Remember that when you apply
these insecticides, the idea is for the
caterpillars to ingest the toxin that
remains on the leaf surfaces. Therefore, post-application irrigation is not
recommended (but may be required
on some labels).
If you are dealing with cutworms
and/or armyworms, we also recommend treating the turf that surrounds
the greens and tees. Generally, two
sprayer-boom widths or 20 to 30 feet
are sufficient to keep caterpillars from
surrounding turf from moving back
onto the green as soon as effective
residues have dissipated.
We have tested the neonicotinoids,
and most seem to have little effect on
caterpillars. However, the combination
products — e.g., Allectus (imidacloprid
plus bifenthrin) and Aloft (clothianidin
plus bifenthrin) — have performed
very well.
By far, the most interesting new
insecticide has been chlorantraniliprole
(Acelepryn). We have applied this product at rates ranging from 0.05 to 0.2
pounds of active ingredient per acre,
and all rates have provided excellent
caterpillar control. At the 0.1 lb. rate,
caterpillar control continued for four
to six weeks, but at the 0.2 lb. rate,
caterpillar control (cutworms, armyworms AND sod webworms) had lasted
from mid-May (when the application
was made) through mid-September!
Several superintendents tried this in
2009, and virtually all have claimed
that they had no caterpillar problems
for the entire season.
So, is season-long caterpillar control
possible? Definitely, but be sure that you
use the higher rate in order to achieve
this long action. At right: Top – Sod webworm larvae
make small brown streaks or crescent
marks at the mow line on golf putting
greens and tees. Middle – Larger sod
webworm adult in typical resting position. Bottom – In our field evaluations
of insecticides to kill turf caterpillars, we
use a large tank of detergent water to
flush up the insects.
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
13
S PORTS TU R F TI PS
By Pamela Sherratt, Dr. John R. Street and
Arly Drake, The Ohio State University
S
ince many schools and parks
and rec. fields in Ohio are
used 24/7, with little or no
down time, one of the goals of our
Sports Turf Extension Program is to
find ways to help sports turf managers
get their fields ready for play in the
shortest time possible. The ideal time
to do any kind of renovation is in the
fall (August 15 to September 15), when
soils are warm, there is a good chance
of rain, and weed pressure is low.
There are other times, though, when
renovation can be done. For example,
some fields are used February through
May, and then there is some down time
in June and July before fall sports
resume in August. Renovating fields
in June and July, however, is far from
ideal. Unfavorable weather conditions
and tremendous pressure from weeds
(like crabgrass, goosegrass and nutsedge)
make it almost impossible to get coolseason grasses established, especially
slow-growing species like Kentucky
bluegrass. One option, of course, is to
use sod, not only because sod gives
instant turf cover, but also because it
offers field managers a great way to get
Kentucky bluegrass back onto the playing surface, after perhaps years of
overseeding with rye.
14
TURF N E W S • March/April 2010
Seed to Play Study
2008–2009
If there is time to seed and, more
importantly, someone available to nurture the newly established seed, then it
is possible to seed successfully in June
and July in Ohio. In a study conducted
at the OTF Research & Education
Facility in both 2008 and 2009, coolseason grasses were seeded in June or
early July to determine the best practices to achieve 100% grass cover in the
shortest period of time, with little or no
interference from weeds. The study area
was native soil (silt clay loam), and there
was supplemental irrigation via an inground system.
Seedbed
preparation
In June 2008, the seedbed area was prepared with minimal soil disturbance: the
existing ground cover was killed with
a non-selective herbicide, then mowed
short to remove as much ground cover
as possible. Prior to seeding, a heavyduty scarifier was used to create shallow
slits and grooves on the soil surface,
so that seed-to-soil contact would be
achieved. The end result of this particular seedbed preparation was minimal
soil disturbance, and therefore minimal
weed competition, with less than 30%
weed cover, which was easily controlled
with a postemergence herbicide (Drive/
quinclorac) once the new grass seedlings
were a month old.
In 2009, the seedbed was prepared
the textbook way — it was tilled to a
depth of 4" and raked to produce a tilth
suitable for seeds. Two seedbeds were
prepared this way: one seedbed was
sprayed with Tenacity (mesotrione)
herbicide the day of seeding, and one
was not. The seedbed that was sprayed
with Tenacity resulted in a clean, weedfree seedbed. The seedbed without
Tenacity resulted in greater than 90%
weed cover, namely crabgrass, yellow
nutsedge and goosegrass (Figure 1).
The conclusion here is two-fold: try
not to disturb the soil, in order to avoid
bringing weed seeds to the surface, and
if the soil is disturbed, use Tenacity
herbicide at the time of seeding to prevent weed seed germination.
The fungicide effect?
During previous studies, some evidence
suggested that fungicides could have
a beneficial, non-target effect on turf
health, particularly during the establishment period.
Figure 1. The seedbed at left was prepared the traditional way, with tilling, resulting in about 90% weed cover. The seedbed at
right was also tilled, but Tenacity (mesotrione) herbicide was applied at time of seeding, resulting in a clean seedbed.
Subdue Applied
No Subdue Applied
Subdue Applied
No Subdue Applied
Figure 2. Applying a fungicide at seeding can have a dramatically positive effect on establishment success.
In 2008, newly seeded perennial ryegrass turf that had been treated with
granular Subdue Maxx (mefenoxam)
fungicide at the time of seeding showed
improved color, density, biomass, sward
height and overall establishment quality,
compared to perennial ryegrass that had
had no Subdue applied. The Subduetreated turf also contained greater
(0.5%) tissue nitrogen compared to
the non-treated. Neither of the grasses
showed symptoms of disease, so the
fungicide appeared to have a non-target
effect on turf health (Figure 2).
In 2009, both granular Heritage
(azoxystrobin) and granular Subdue
Maxx were applied at time of seeding.
Results were similar to those seen in
2008, in that fungicide-treated turf
provided better quality and quicker
establishment. Mid-way through the
study, however, the untreated and Subdue-treated turf got infected with rust
(Puccinia), and so the non-target effect
was lost. The Heritage treated-turf was
not affected by rust.
Cultural practices and
seeding rates
To expedite rapid establishment, seeding rates were slightly higher than
normal. The following cultivars were
selected for quick establishment:
• Kentucky bluegrass — 50:50
blend of Barari and Barimpala,
seeded at 4 lbs./1,000 sq. ft.
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
15
S PORTS TU R F TI PS
•
Continued
6 Weeks After Seeding
PRG 4 WAS
Figure 3. Perennial ryegrass treated with a fungicide at seeding shown above (at left) at 4 weeks after seeding, and (at right)
perennial ryegrass, Kentucky bluegrass and tall fescue at 6 weeks after seeding.
• Perennial ryegrass — 50:50 blend
of Barlennium and Bar LP 7613,
seeded at 10 lbs./1,000 sq. ft.
• Tall fescue — 50:50 blend of
Barrobusto and Bravado, seeded
at 8 lbs./1,000 sq. ft.
Starter fertilizer (12-24-8) was
applied at 1 lb. N/1,000 sq. ft. at time
of seeding, then at 0.5 lb. N/1,000
sq. ft. at 14 and 28 days after seeding.
Irrigation was set up on a syringing
cycle, for 5 minutes each cycle, at 8
a.m., 11 a.m., 2 p.m. and 5 p.m. each
day until full germination, and then
reduced to twice daily. Once grass was
fully established, irrigation was used
only to replenish ET.
A critical part of seedling establishment is mowing. As soon as the seedlings reach 3" tall, they should be
mowed with a rotary mower, daily if
possible. Regular mowing promotes
tillers, thereby increasing turf density
and percent ground cover. If daily mowing is out of the question, mowing at
least three times a week in the establishment phase is essential to the turf being
ready for play. Mowing once a week will
not produce dense turf quickly enough.
Results
As expected, the first grass to germinate
was perennial ryegrass (3 days), followed
by tall fescue (5 days) and Kentucky
bluegrass (6 days). Percent ground cover
16
TURF N E W S • March/April 2010
was determined by both visual rating
and by point quadrant, whereby actual
plants in a given area are counted (just
the kind of job a turf student likes to
take on!).
At four weeks after seeding (WAS),
perennial ryegrass with Heritage was at
98% ground cover, with Subdue at 94%
cover and untreated at 88% cover. At
six WAS, Kentucky bluegrass with Heritage was at 85% ground cover, with
Subdue at 77% cover and untreated at
71% cover (Table 1). Note: At 6 WAS,
all treatments that had not treated with
Heritage had rust.
Measuring
“playing quality”
There are several criteria for determining
when turf is “playable,” notably percent
ground cover and shear strength. The
shear strength component is typically
measured by two pieces of equipment:
(1) rotational shear equipment that
mimics a foot rotating on turf (developed by Canaway in 1975) and (2)
lateral shear equipment that mimics a
foot digging into the turf and pushing
out a divot (developed by Clegg).
At four WAS, all perennial ryegrass
treatments were determined to be playable, with shear strengths that exceeded
recommendations and ground cover at
or around 90%. At six WAS, all treatments displayed acceptable shear
strengths. Kentucky bluegrass treated
with Heritage at time of seeding was
at 85% ground cover, with tall fescue
at 81% ground cover (Table 2 and
Figure 3). It should be noted that soil
moisture was about 25% at time of
testing. Saturated native soils may have
given lower shear-strength results.
Conclusions from
the Study
• A clean seedbed is possible by
creating minimal soil disturbance
or by applying Tenacity herbicide
at time of seeding.
• Perennial ryegrass was playable
four weeks after seeding.
• Kentucky bluegrass and tall fescue
treated with Heritage were playable
six weeks after seeding. Untreated
tall fescue may also be playable
in six weeks.
• Fungicides have a non-target
effect on turfgrass health and
could possibly be used to
enhance establishment.
• This is not a low-maintenance
plan. For this program to work,
there must be supplemental irrigation (syringing at first), applications
of starter fertilizer and frequent
mowing as soon as possible.
Thanks to the study sponsors:
Syngenta, Barenbrug and The
Ohio Turfgrass Foundation. Continued •
S PORTS TU R F TI PS
Table 1: Establishment Rate (Percent Ground Cover) of Three Cool-Season Grasses, Determined by Point Quadrant. (DAS = days after seeding)
Treatment
July 22
(5 DAS)
July 28
(11 DAS)
August 4
(18 DAS)
August 11
(4 WAS)
August 18
(5 WAS)
August 25
(6 WAS)
PRG + Subdue
60%
71%
83%
94%
90%
92%
KBG + Subdue
0%
23%
46%
64%
67%
77%
TF + Subdue
4%
42%
63%
65%
71%
71%
PRG + Heritage
54%
60%
94%
98%
98%
100%
KBG + Heritage
2%
31%
58%
52%
79%
85%
TF + Heritage
5%
42%
69%
73%
65%
81%
PRG
67%
75%
69%
88%
85%
94%
KBG
<1%
27%
48%
50%
58%
71%
TF
<1%
44%
52%
60%
65%
81%
LSD (0.05)
17%
14%
25%
19%
18%
11%
Table 2: Playing Quality at Six WAS, Determined by % Ground Cover and Shear Strength
Treatment
Percent Cover
(Point Quadrant)
Rotational Shear*
Strength (Nm)
Lateral Shear**
Strength (Nm)
PRG + Subdue
92%
64.6
117.7
KBG + Subdue
77%
59.8
113.1
TF + Subdue
71%
61.2
125.2
PRG + Heritage
100%
69.8
115.7
KBG + Heritage
85%
55.4
102.0
TF + Heritage
81%
60.7
118.2
PRG
94%
60.2
106.0
KBG
71%
53.4
89.3
TF
81%
56.8
115.3
LSD (0.05)
11%
6.0
24.4
* STRI recommendation (Canaway, 1990, McClements and Baker, 1994b) is >25 Nm for soccer and >35 Nm for rugby
** Mature, dense Kentucky bluegrass ~ 90Nm (Sherratt et.al., 2005)
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
17
L AW N CA R E
18
TURF N E W S • March/April 2010
By David J. Shetlar, Ph.D., Professor of Urban Landscape Entomology,
The Ohio State University, OSU Extension & OARDC
WHY
control pests without pesticides? I can answer
this with two words — customer perceptions!
Many people are questioning the value of picture-perfect lawns with absolutely no blemishes (no weeds or discoloration caused
by insects or diseases). In fact, some cities and provinces in Canada have recently
banned the use of all “cosmetic” pesticides (i.e., pesticides used to maintain urban
landscapes), and they have severely limited the types and amount of fertilizers.
Environmental activists in the United States are also heavily involved with this
chemical-reduction effort. These are usually the same folks that propose using only
native plants and turning your yard into a wildlife habitat or a vegetable garden.
Obviously, the majority of your customers do not really want this kind of
lifestyle, but an ever-increasing number
ARE asking for less-radical alternatives.
In this two-part article (don’t miss the
May/June issue of Ohio Turf News for
part two!), I want to cover what we
know works, and what doesn’t work,
to manage insects that commonly
attack our lawns.
The important insects
In general, Ohio lawns are often severely
damaged by only three pests — white
grubs, billbugs and hairy chinch bug. In
the 25 years I’ve been working in turf,
I have seen only a couple of lawns that
were damaged by caterpillars (a rare
occurrence). Even in these cases, a little
irrigation after the defoliation allowed
the lawn to recover rapidly. Grubs, billbugs and chinch bugs, however, can kill
turf roots and/or stems, which leads to
weed emergence and the need to renovate the lawn.
Cultural insect controls
Cultural control simply means making the environment less suitable for
a pest to thrive. This option can also
Opposite Page: Kentucky bluegrass
lawn killed by the bluegrass billbug and
drought. Notice the green patches, which
are endophytic perennial ryegrass that
were also in the lawn!
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
19
L AW N CA R E
•
Continued
Life stages of the bluegrass billbug: egg, larval instars, pupa and adult. An adult billbug is 3/8" long.
include mechanical control (crushing,
grinding, spiking, etc.) and using grass
species or cultivars that are less susceptible or resistant to pests.
Endophyte-enhanced turf
In my opinion, the first cultural control
that should be considered for all lawns
is the use of endophyte-enhanced turf.
Endophytes are symbiotic fungi that
live within the plant’s tissues where the
fungus receives nutrients and water.
In turn, the fungus produces a set of
chemicals that are toxic to insects, as
well as other chemicals that seem to
help the plants survive extremes of
heat and drought.
Fescues and ryegrasses are the only
turf species that contain endophytes.
Turf-type tall fescue and perennial ryegrass cultivars are often sold with claims
of containing high levels of endophytes.
Although fine fescues also contain endophytes, these species do not perform
well in sunny lawns.
A turf stand with about 40% of
endophyte stems is sufficient to knock
out billbugs, chinch bugs and sod webworms. This level can be easily achieved
by slit-seeding high-endophyte seed
into an existing stand of non-endophyte
turf, such as Kentucky bluegrass. Since
tall fescue cultivars usually have the
same shade of green as Kentucky bluegrass, this is probably the best selection.
Many of the newer perennial ryegrass
20
TURF N E W S • March/April 2010
cultivars are darker green, and these
will segregate out into visible patches
of lighter and darker grass.
So, if a lawn is repeatedly being
attacked by billbugs or chinch bugs,
slit-seed in some endophytic turf seed
for a long-term elimination of these
pests. It usually takes two seasons for
the endophyte level to reach effective
suppression of the pest populations.
Unfortunately, these endophytic
grasses do not translocate their toxins
to the roots where grubs feed. However,
we now have good research that shows
that tall fescue cultivars can tolerate
more grubs per square foot than Kentucky bluegrass or perennial ryegrass.
Resistant cultivars
Some turfgrass cultivars have been
evaluated for their resistance to some
insects, primarily billbugs. It appears
that very fine-textured (thin-stemmed)
Kentucky bluegrasses are not easily used
by billbugs. The thin stems apparently
hinder egg-laying (thick seed stems are
preferred), and the larvae have a difficult
time burrowing down the thin stems to
the crowns. Many of the first improved
Kentucky bluegrass cultivars (e.g.,
Marion and Glen) had very thick stems,
making them highly preferred by billbugs. Be sure to ask your seed provider
for any data on insect resistance associated with the cultivars used in their
seed blends.
Thatch reduction and
aerification
Regular thatch reduction and/or intensive core aerification seems to help
reduce the chances of getting high grub
populations. A large study of lawns in
Rochester, NY, found that newly established lawns didn’t get damaging grub
populations for the first three to five
years, but then grub populations often
had significant outbreaks. White grubs
eat organic matter, and it usually takes
three to five years to build up sufficient
organic matter in the top inch of soil
and thatch to support white grubs.
In an Ohio State study (on bentgrass) where compost was added to the
turf on a regular basis, white grub populations did not increase and actually
may have decreased! Why? It appears
that compost, while organic, contains
little useful organic carbon that can
be used by the grubs for food. Also,
this compost improved the color and
growth of the turf and may have
actually decreased the formation of
thatch layers.
Intensive coring, especially in late
summer, can also physically kill many
white grubs. Even just small nicks
in the exoskeleton can be lethal to
white grubs.
Therefore, practices that reduce
thatch development — using compost
as a top dressing and/or minimal fertilizer, regular coring or even dethatch-
Continued •
L AW N CA R E
Life stages of the hairy chinch bug: egg, five nymphal instars, full-winged adult and short-winged adult. An adult is 3/16" long.
Life stages of the Japanese beetle: egg, three larval instars, pupa and adult. An adult is 1/2" long.
ing operations — may reduce the risk
of white grub outbreaks.
Mowing high
Mowing high (we normally recommend 2.5" to 3" for Ohio lawns) tends
to increase the depth and amount of
roots. While this can increase the
organic matter in the upper soil level,
turf plants with deep and extensive root
systems can tolerate more grubs per
square foot than shallow-rooted turf.
Irrigation strategies
Irrigation can have a significant effect
on the expression of insect pest damage,
and it can even suppress certain pests.
Billbugs appear to be omnipresent in
Ohio lawns, but we usually don’t see
their damage except when we get a
significant drought that begins in early
to mid-June. If you have irrigation
(or we receive normal or above normal
rainfall at this time), billbug damage
is simply not evident.
On the other hand, our white grub
species lay dehydrated eggs that must
absorb moisture within 36 to 48 hours
after being laid or they won’t develop.
This is why lawns that are irrigated in
July into early August are often damaged by white grubs, but lawns that
are allowed to go dormant during this
period rarely have damaging numbers
of white grubs.
Our recent studies on hairy chinch
bug also indicated that the summer
populations crash when the lawn goes
dormant, but they thrive if the turf is
kept growing. So, keep the lawn green
through June, but allow it to go dormant in July and August. Coming next issue…
In the May/June issue of Ohio
Turf News, I will cover the various
options of biological controls of
lawn turf insects, including predators, parasites and pathogens.
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
21
GOLF COU R S E TI PS
22
TURF N E W S • March/April 2010
By Gerald Huseman, Ohio Sales Specialist,
BASF Professional Turf & Ornamentals
In
an industry pressured for
cost savings, superintendents are considering every
option, including going natural. These
areas, called by many names (including
native, natural and naturalized), can also
help make a golf course more marketable during these difficult economic
times, by providing increased aesthetic
interest for golfers.
Naturalized areas help create a contrast to intensely managed turf, and
they improve wildlife habitat. While an
aesthetic case for naturalized areas can
be easily made, many superintendents
are converting intensely managed turf
to naturalized landscapes to cut their
input costs related to fuel, fertilizer,
irrigation, pesticides and labor. The
deep root systems of these naturalized
areas, for example, are more tolerant
to environmental stresses and require
less irrigation. Properly going natural,
however, should not be confused with
letting Nature take over.
Naturalized areas left to grow at
nature’s will are bound to become large
weed patches and over-grown eye sores
that can become a no-man’s land for
irretrievable golf balls. Unlike turf and
groomed landscapes, a naturalized area’s
success relies on a different type of plant
management and a low-maintenance,
but methodical, approach that includes
both preemergence and postemergence herbicides.
Choosing plants and
planning maintenance
The types of indigenous or non-native
plants that you choose for naturalized
areas have a significant impact on
maintenance needs.
Monostands or mixes of fescues, lovegrass, bluestems, broomsedge, wheat-
grass, indiangrass and others can provide
a clean contrast to playable turf and
require minimal maintenance inputs.
They are great for sloped areas prone
to erosion, and some varieties even
have natural weed defenses.
Native flowers and wildflowers add
color to a course’s greenscape, but they
require more care to ensure seasonal
blooms and growth succession over
invasive, aggressive weeds. When grown
from seed, wildflowers may take up
to three years to provide the impact
desired. Some of the most popular
choices for golf courses include cosmos,
yarrow, baby’s breath, black-eyed susan,
primrose, poppy and Shasta daisy, to
name a few.
Controlling weeds in a naturalized
area inhabited by wildflowers can be a
challenge for superintendents. Herbicides meant to knock down broadleaf
weeds may also kill wildflowers, which
are categorized as broadleaf species.
As a result, these wildflower areas may
require hand-weeding and spot spraying to remove unsightly broadleaf weeds.
Grassy weeds, however, can be controlled with selective herbicides. If
planting wildflowers, superintendents
should consider the size of the planting
area, realizing that these areas will
require some hand-weeding to achieve
the full benefits.
Getting started on
going natural
Establishing strong, healthy plants is
key for weed management in low-maintenance, naturalized areas. When beginning a new area, use a non-selective
chemical treatment to eliminate weeds,
and then lightly till. Then use a low
seed rate per acre to avoid thick stands
of vegetation. Be sure to time seeding
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
23
GOLF COU R S E TI PS
•
Continued
with seasonal rains to minimize the
need for irrigation. With new areas, it
is important to communicate progress
to members, because plants may take
years to develop and achieve the
desired effect.
One way to avoid waiting for the
area to develop is to use established
plants, if available. Plant them in the
fall to make the most of favorable soil
temperatures and decreased weed
pressure. Superintendents could also cut
costs by building an out-of-sight nursery to grow native varieties until they’re
ready for planting. Mature plants should
be spaced apart so players have room
to walk in and play a missed shot back
onto a fairway. A number of grass
options — including lovegrass, fescues,
broomsedge and bluestem — work
well in these areas.
Managing weeds and
promoting healthy,
playable growth
Seasonal thinning, trimming, mowing
and spraying naturalized areas should be
included in a golf course’s routine main-
tenance in order to sustain the integrity
and playability of the course landscape.
A management plan should start
with an inventory of current herbicides
in the chemical-storage building. Categorize your existing herbicides by application timing, use areas and weeds
controlled (see chart). Note preemergence and postemergence herbicides,
whether use sites are appropriate for
wildflower areas and native grass areas,
and their control of broadleaf weeds,
sedges and grassy weeds.
While many herbicide products
labeled for golf course use do not list
native grasses and wildflowers specifically, language on the label usually allows
you to evaluate the herbicide on your
particular species. You should test the
product on a small area to determine
tolerance before making applications to
larger areas. In addition, many product
labels include native grasses and wildflowers that are tolerant to a particular
herbicide in the ornamental section of
the label.
Preemergence herbicides should be
the pillar of any naturalized-area maintenance plan. Most preemergence herb-
Consider mowing naturalized areas twice a year — once in the spring to provide for a
clean, fresh growing season and then again in the fall before plants go into dormancy.
24
TURF N E W S • March/April 2010
icides labeled for golf course use evolved
from crop applications, which typically
control tall and unsightly weeds commonly found in naturalized areas. These
include grassy weeds such as barnyardgrass, foxtail, johnsongrass, panicum
and witchgrass, as well as broadleaf
weeds like lambsquarter, pigweed,
spurge and smartweed. Since most
preemergence herbicides affect only the
roots of germinating weed seeds, they
are generally labeled for use on mature
grasses with a well-established root system. Using herbicides to preventatively
control weeds will be the most costeffective strategy. If you can prevent
outbreaks with one product application, you’ll save yourself the time and
expense of applying multiple products
on multiple weed varieties.
Superintendents should apply herbicides annually as part of their routine
maintenance. Other strategies, such as
mowing and thinning the vegetation,
will promote healthy growth and keep
the area playable.
Consider mowing naturalized areas
twice a year — once in the spring to
provide for a clean, fresh growing season and then again in the fall before
plants go into dormancy. Spring and
fall are ideal times to apply a preemergence herbicide to control weeds.
After an area has been established for
a few years, consider getting a permit
for a controlled burn of the area. Scheduling an annual burn during the early
spring months will encourage hearty
growth and renew the soil.
Once new growth appears, apply a
preemergence herbicide before grassy
A naturalized area’s success relies on
a low-maintenance, but methodical,
approach that includes both preemergence and postemergence herbicides.
Continued •
GOLF COU R S E TI PS
Inventory Your Herbicides and Categorize Their Use in These Areas
* Recommendations complied by BASF Professional Turf & Ornamentals’ technical staff. Disclaimer: Consult individual product labels to determine
individual species tolerance. Most product labels allow users to evaluate species not on the label. User assumes all risk. This is a partial list of
products and is provided as a guide.
Company
Name
Product
Name
Active
Ingredient
Preemergence — Grasses and broadleaves
Application Timing
Preemergence
Postemergence
Use Areas
Weeds Controlled
Native
Grasses
Wildflowers
Grasses
Broadleaves
BASF
Pendulum herbicide
Pendimethalin
x
x
x
x
x
Syngenta
Barricade
Prodiamine
x
x
x
x
x
Dow AgroSciences
Dimension
Dithiopyr
x
x
x
x
x
United Phosphorus Inc.
Surfian
Oryzalin
x
x
x
x
x
Amvac Chemical Corp.
Dacthal
DCPA
x
x
x
x
x
Sedges
Postemergence — Non-selective
Bayer
Finale
Gulfosinate-ammonium
x
x
x
x
x
Monsanto
Roundup
Glyphosate
x
x
x
x
x
x**
Postemergence — Sedges
BASF
Basagran herbicide
Sodium Bentazon
x
x
x
Gowan
Sedgehammer
Halosulfuron methyl
x
x
x
Postemergence — Grasses
BASF
Drive XLR8 herbicide
Quinclorac
x
x
x
Bayer
Acclaim Extra
Fenoxaprop-P-ethyl
x
x
x
x
BASF
Segment herbicide
Sethoxydim
x
x*
x
x
Syngenta
Fusilade II
Fluazifop-P-butyl
x
x
x
x
Postemergence — Broadleaves
Dow AgroSciences
Turflon
Triclopyr
x
x
x
Dow AgroSciences
Lontrel
Clopyralid
x
x
x
Multiple mfgs.
Various
2, 4-D
x
x
x
Multiple mfgs.
Various
Dicamba
x
x
x
PBI Gordon
Trimec Classic
2, 4-D + MCPP + Dicamba
x
x
x
LESCO
Three Way
Dicamba + 2, 4-D + MCPP-P
Carfentrazone-ethyl + 2, 4-D
x
x
x
PBI Gordon
SpeedZone
+ Mecoprop-p + Dicamba
x
x
x
Dow AgroSciences
Confront
Triclopyr + Clopyralid
x
x
x
Chart Guide: x* May be used in fine fescue x** Suppression
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
25
GOLF COU R S E TI PS
•
Continued
This naturalized area features a monostand of ‘Aurora’ hard fescue, providing a visually pleasing textural and color contrast.
and broadleaf weeds invade the area.
Postemergence broadleaf herbicides are
effective on naturalized grass areas, but
eliminating unsightly grassy weeds can
be more challenging. There are several
postemergence grass herbicides that can
be used, but study product labels closely
to determine if your stand is tolerant
to the herbicide.
Naturalized areas on golf courses
continue to be a developing trend. And
while they are not maintenance free,
naturalized areas can reduce the amount
of management required on the overall
course and increase aesthetics. Properly
managed naturalized areas can be mutually beneficial to superintendent budgets
and player expectations. And when created and managed methodically, naturalized areas can give the golf course a
visually appealing contrast to the manicured playing areas. 26
TURF N E W S • March/April 2010
Maintenance Schedule Breakdown
1. Mow in the spring and apply a
preemergence herbicide.
2. Monitor the amount of wildlife
living in the naturalized area. If
animals or insects have become
pests to players, decrease the
amount of food- and sheltergiving plants.
3. Spot-spray and hand-weed as
needed if weed pressure increases
during summer months.
4. Mow in the fall and apply a preemergence herbicide before
dormancy hits.
5. If allowed, consider burning to
clean out debris and vegetation
to promote new growth.
6. If desired, label the indigenous
grasses and flowers to both educate players and help remind
maintenance crews which plants
are intentional.
The Ohio Tur fgrass Foundation Magazine • TURF N E W S
27
T U R F TA L K
By David S. Gardner, Ph.D., Dept. of Horticulture and Crop Science, Ohio State University
M
ost of the weeds that we
encounter in turfgrass are
either summer annuals
(which germinate in spring, grow and
set seed in summer, then die in the fall)
or perennials (which persist for multiple seasons). There are, however, a few
winter annual weeds in turfgrass, such
as annual bluegrass, common chickweed and henbit. Less-common winter
annual weeds in turf include shepard’s
purse, veronica and purple deadnettle.
During the month of March and perhaps the first couple of weeks of April,
these weeds can be very noticeable
in turf.
In some years, these weeds may warrant control, and understanding the
ecology and life cycle of these weeds can
help you determine appropriate control
strategies. Winter annuals germinate in
the fall and bloom and set seed in the
spring. Like summer annual weeds, they
spread by seed, not vegetatively like
ground ivy or other perennial weeds.
Properly identifying a weedy species
is the first step to determining the best
control strategy. Use the information
in the photo captions to identify common chickweed and henbit, which are
the two most common winter annual
weeds in turf in Ohio (Figure 1). Also,
a few perennial weeds are more visible
28
TURF N E W S • March/April 2010
in late winter or early spring, such as
wild onion, wild garlic and Star-ofBethlehem (Figure 2).
Henbit and common
chickweed
Both are highly competitive in thin or
dormant turf or in newly seeded areas.
However, a vigorous lawn will tend to
out-compete them. So, the best defense
against henbit and common chickweed
is to properly maintain your turfgrass.
This includes selecting the right species
for the location and usage, as well as
proper cultural practices (proper mowing, fertility, irrigation and aeration).
Best control of henbit and chickweed with postemergence herbicides
is achieved if applications are made
in the fall to actively growing plants.
Ideally, henbit and chickweed can be
controlled with the same fall application that targets dandelions and other
perennial broadleaf weeds. Remember
to read and follow the manufacturer’s
directions and recommendations on
the label.
If an early spring herbicide is
required, the application’s timing is
very important for optimal control.
The chief concern is that a dense mat
of winter annual weeds, after they die
in the spring, will open a bare spot in
the turf that may be filled in by crabgrass and other summer annual weeds.
It is best to hit these weeds early, before
they flower. That way, you prevent seed
set and give the turfgrass some time to
fill in.
You must use extra caution with
spring-applied herbicides, since newly
emerging leaves of ornamentals are
extra sensitive to broadleaf herbicides.
Avoid applications when temperatures
are above 80°F or when it is windy.
Wild garlic and wild
onion (Allium sp.),
and Star of Bethlehem
(Ornithogalum sp.)
These species become quite noticeable
in turf in late winter or early spring
because they green up and grow a few
weeks before the turf does. As a result,
they tend to be visible as clumps of
foliage up to 12" in height in otherwise
still dormant turf. Like our grasses, they
are monocots, but they are not grasses.
Just as sedges are a different species
than grasses, so to are the Allium and
Ornithogalum species. In fact, these are
more closely related to amaryllis and
daffodils. And there in lies the problem
— there are not scads of research dol-
Figure 1. Winter Annual Broadleaf Weeds
Common Chickweed — Stellaria media
(Glabrous leaves are rounded at the base and pointed at the
tip. The small white flowers have deeply notched petals.)
Henbit — Lamium amplexicaule
(Square stems. Terminal leaves attached directly to main stem.
Lower leaves on short branches.)
Figure 2. Monocotyledonous Weeds of Late Winter
Wild Garlic — Allium vineale
Wild Onion — A. canadense
(Garlic has hollow leaves; onion has flat leaves.)
lars being devoted to develop herbicides that effectively control daffodils or
related species. Thus, dedicated selective
controls for these weeds do not exist.
If you have a serious problem with
these weeds, you can attempt to treat
them with the three-way postemergence broadleaf herbicide of your
choice, but with the caveat that the
herbicides are not specifically designed
to control these weeds and, therefore,
Star of Bethlehem — Ornithogalum umbellatum
(The white flowers have six petals. Leaves have a distinct,
grooved midrib.)
your results may be variable. 2,4-D
alone is also a good choice.
Your best option may be to keep
them cut short, either by mowing or
with hand shears. As bulbs, they persist
vegetatively for a period after flowering and then the foliage dies back for
the season. If you mow or otherwise
defoliate them early, you weaken the
plant and diminish its ability to develop
next year.
Final thoughts
Winter annual weeds are usually not
our most serious weeds in turf. However, they can, on occasion, become
quite noticeable. The key is to recognize the uniqueness of each weed’s life
cycle, and target your herbicide application for the right time of year. The Ohio Tur fgrass Foundation Magazine • TURF N E W S
29
CA L E N DA R O F E V E N T S
June 17
August 11
Northeast Ohio Lawn Care Seminar
(Ohio Lawn Care Association)
Wooster, OH
OSU Turfgrass Research Field Day
Columbus, OH
October 28–30
July 10
ANLA One-Day Landscape Tour
(American Nursery & Landscape Assn.)
Columbus, OH
Green Industry & Equipment Expo
Kentucky Exposition Center
Louisville, KY
December 6–9
July 26–30
TPI Summer Convention
& Field Days
(Turfgrass Producers International)
Sheraton New York Hotel
New York, NY
OSU TU R FG RASS SCI E NCE TEAM
Horticulture &
Crop Science
Entomology,
Continued
Dr. Karl Danneberger
danneberger.1@osu.edu
Dr. David Gardner
gardner.254@osu.edu
Dr. Ray Miller
miller.5@osu.edu
Dr. John Street
street.1@osu.edu
Ms. Pamela Sherratt
sherratt.1@osu.edu
Ms. Deborah Holdren
holdren.27@osu.edu
Mr. Matt Williams
williams.1278@osu.edu
Ms. JoAnne Kick-Raack
kick-raack.1@osu.edu
Mr. Kevin Power
power.1@osu.edu
Entomology
Dr. Parwinder Grewal
grewal.4@osu.edu
Dr. Dave Shetlar
shetlar.1@osu.edu
ADVE RTI S E R I N D EX
Ag. Tech. Institute
Dr. Daniel Voltz
voltz.5@osu.edu
Mr. David Willoughby
willoughby.18@osu.edu
Athletics
Plant Pathology
Dr. Michael Boehm
boehm.1@osu.edu
Mr. Todd Hicks
hicks.19@osu.edu
Mr. Joseph Rimelspach
rimelspach.1@osu.edu
School of Natural
Resources
Ohio Turfgrass Conference and Show
Greater Columbus Convention Center
Columbus, OH
Mr. Dennis Bowsher
bowsher.33@osu.edu
Mr. Brian Gimbel
gimbel.1@osu.edu
International
Programs
Barenbrug USA . . . . . . . . . . . . . . Back Cover
www.BarUSA.com
Kurtz Brothers Landscape Supply . . . . . . . . 5
www.Kurtz-Bros.com
Massey Fergason — Witmer’s . . . . . . . . . . . 3
Medina Sod Fams, Inc. . . . . . . . . . . . . . . . . 5
www.MedinaSodFarms.com
Quali-Pro . . . . . . . . . . . . . Inside Front Cover
www.Quali-Pro.com
Texas Sod Leasing . . . . . . . . . . . . . . . . . . . . 7
www.TexasSod.com
Wehrkamp Enterprises, Inc. . . . . . . . . . . . 27
www.WehrkampEnterprises.com
Mr. Mike O’Keeffe
okeeffe.1@osu.edu
Dr. Ed McCoy
mccoy.13@osu.edu
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TURF N E W S • March/April 2010