Cool August, Warm September??
Weather:
The weather pattern (heavy late August rains and fourth chilliest
August on record in northern Illinois) has broken temporarily
with the onset of September. Current highs in the mid 80's are
sparking 'warm' comments from forecasters especially with high
humidity pushing 'feels like' temperatures into the 90's . Remember
when real 90 degree temperatures, (which we've only had 3 days
of this year), were considered warm? Hurricane Frances is putting
a hold on weather pattern changes throughout the eastern half
of the country, so this warm and dry trend should stick around
for the next few days at least, meaning a warm & sultry
Labor Day weekend. Temperatures could break back to fall-like
by next week depending on the storm's path.
The August of 2004 was 4-5 degrees below normal on average for
northern Illinois, and the entire meteorological summer (June
- August) ran a full 2-3 degrees below normal making it the
16th coolest summer on record. So what does this mean for winter?
According to history… nothing. In a Tribune article, Tom Skilling
examined the last 6 Augusts that had temperatures as low as
this one and found that 3 winters were warmer and 3 winters
were cooler than normal. So, no clues as to when the snow will
fly…
Diseases:
The broken record continues to skip here in the disease section
as dollar spot persists as a weight around the neck of most
superintendents in northern Illinois (so much so that this section
could almost be copied and pasted from one newsletter to another).
The fall-like weather and conditions of August and all of summer
for that matter have been just perfect for dollar spot. Application
intervals for fungicides are being pinched to their limit, as
evidenced in our fungicide trials where the best treatments
are lasting 17-20 days at our most severe testing site. Skipping
sprays is nearly impossible, and the onset of September (when
dollar spot SHOULD be spiking) probably will not help matters
much.
In a year with this kind of severity, fungicide rotation should
be a priority (unless you are trying to go with chlorothalonil
alone on a tight schedule!). I am concerned that late season
fungicide resistance issues could develop, as fungicide use,
and therefore selection of resistant strains, has been necessary
for the entire course of the season. In some of our plots, we
are starting to observe fungicides that worked earlier starting
to break down as the season wears on, which could be due to
this selection process (since we apply the same fungicide over
and over again on 14 or 21 day schedules).
Limited outbreaks (only 3 reports) of Pythium were reportedduring
the warm, humid, and wet spell between August 24-26th , but
was quickly vanquished by a cool front. This labor day weekend
could produce these same kind of limited outbreaks especially
if nighttime temperatures stay in the high 60's, but if the
cool temperatures come back in early next week as expected then
severity should be minimal. Nice not having to really worry
about Pythium until September.
With the recent cool and wet weather in northern IL, it seems
that fairy ring problems have slacked off a bit (see
last newsletter), but have been replaced by the
resurgence of rings from Rhizoctonia species (most probably
zeae). So far, these reports have been few and far between,
but we have seen a few pop up here at Golf House. If this heat
doesn't persist, I would expect to see more as the month progresses.
We also have one suspected case of bentgrass dead
spot in Chicagoland, but we are still waiting for it to grow
out in culture to positively identify it. The reason this disease
is suspect is 1) it is occurring on two year old greens that
had been previously gassed with methyl bromide, 2) symptoms
of sunken collapsed spots about ball mark in size, and 3) it
falls in the typical timing of symptom expression which is the
late summer - early fall months. Fungicide options if this disease
is diagnosed include Daconil, Cleary's 3336, Emerald, Medallion,
and Insignia.
Lastly, early reports of zoysia or large patch came in late
August from several courses in the southern Illinois area, This
disease is a month ahead of schedule because the soil and thatch
temperatures have been more reminiscent of late September than
August. Soil temperatures have been teetering in the low 70's
- high 60's, and preventative applications are recommended when
thatch temperatures (which presumably could have been a little
lower than 2 inch soil temps) drop below 70. Recommended preventatives
include Heritage, Prostar, PCNB (for the brave souls in early
fall), and Bayleton.
Insects:
Grub and associated predator damage has been reported as far
north as Bloomington now, with extensive damage now occurring
in southern Illinois. The cool weather pattern does not seem
to have slowed down egg-laying or larval development, since
these reports are right about in line with normal timings of
outbreaks. While mowing, I did notice quite a few Black turfgrass
Ataenius beetles roaming around on our greens here this past
week, which could indicate their second generation egg laying
and potential to add to the annual white grub population later
this month. On a brighter note, cutworm activity seems to have
declined over the last week or so...
Stringy Poa and Moss:
One report came in late last week of symptoms of Poa that can
only be described as stringy or hairy (see pic above). Symptoms
include stem elongation or etiolation, and a slight curling
of the lower leaves. The cause is yet unknown, but it is just
unsightly and doesn't seem to cause any large amount of damage
to a turfgrass area. Last year we did see somewhat similar symptoms,
except last year's samples had a clear translucent margin on
the stem right above the crown, which is not present in this
case. We attributed symptoms to PGR bounce back then, but in
this instance we are not so sure it isn't biologically based
(some epiphytes or pathogens can produce a gibberelin which
can cause this kind of growth).
The mild, moist weather has caused many moss outbreaks on greens
throughout Chicagoland. Some success for moss problems has been
reported with fungicides such as Junction (copper hydroxide
and mancozeb), Daconil, Dithane, Fore, and Iron Sulfate, as
well as the baking soda and Dawn mixtures.. One notable tank
mix for moss control supplied by Wayne Otto (via Les Rutan@Crystal
Tree) is Spotrete @ 4.5 oz/1,000, Echo (90% A.I) @ 5.7 lbs/A,
& Dithane @ 4 oz/1,000 applied on a 2 week schedule. A lot
of chemical, but some guys swear by it.
+++++++++++++++++++++++
Thanks for your support of this, as well as all
of our research programs,
Randy
Kane
CDGA
Director of Turfgrass Programs
Midwest Golf House
11855 Archer Ave
Lemont, IL 60439
630-257-8126
Lee
Miller
CDGA
Manager of Turfgrass Research
Midwest Golf House
11855 Archer Ave
Lemont, IL 60439
630-257-2005 x.106
