From Frost
to Boil Again!!
Weather:
Over the last two weeks we have continued to experience
typical spring conditions in northern and central Illinois -
cold fronts come through bringing (much needed) showers, then
it warms back up on the backside. We continue to run a pretty
significant rainfall deficit for '04, even though many areas
received some nice totals Apr 24-25 and Apr 30-May 2. At Midway
and O' Hare airports, only 35 and 20% of average precipitation
fell in April, and many sites were significantly below last
year's April rainfall total (see table below). The beginning
of May also brought record low temperatures at Rockford and
O' Hare, with some sites reporting lows in the mid '20s. Soil
temperatures remain fairly cool due to recent cold overnight
temperatures. Click
here to look at a current soil temperature map.
April Rainfall Totals
|
City
|
2003 April Rainfall (")
|
2004 April Rainfall (")
|
% difference
|
|
St. Louis
|
2.66
|
2.04
|
-23%
|
|
Peoria
|
3.41
|
2.12
|
-38%
|
|
Bloomington
|
3.27
|
1.54
|
-53%
|
|
Frankfort
|
5.25
|
3.86
|
-26%
|
|
Elmhurst
|
4.10
|
1.25
|
-70%
|
|
Libertyville
|
3.55
|
2.28
|
-36%
|
|
N. Barrington
|
2.24
|
1.80
|
-20%
|
Forecasts for the next few days show a significant
warm up, and possibly our first serious foray into high temps
(>85 F) and higher relative humidity. Keep an eye out for
the usual spring afflictions, including Rhizoctonia patches,
leaf spots, and maybe even some early dollar spot. Judging by
the record heat accumulating in the southwest (even LA and San
Diego), we could be in for a hot summer, depending on how the
jet stream/storm patterns setup in June and July. That is where
this weekend's heat is coming from by the way… So far, a hot
month of May seems to be in store for the area, but only average
conditions are predicted for the next 90 days in the upper Midwest.
Poa Update:
Northwest Illinois started seeing its first smatterings
of seedheads at the end of April, meaning most of Illinois should
be seeing seedheads by now. In the south and western suburbs
of Chicago, many Poa annua biotypes are starting to flower,
meaning seeding in central Illinois should be going full-bore
by now.
It appears as though some biotypes started the
seeding process fairly early this year, as we have seen evidence
and have had a few reports of limited (i.e. ineffective) seedhead
suppression with Proxy + Primo tank mixes. However, users should
keep in mind that Proxy is not meant to be a 100% control, and
we don't know how all biotypes of Poa are going to respond.
Plus we still don't know the best timing for treatments, or
whether the 3 oz rate on a shorter interval will be as effective
as the 5 oz rate. Early indications on our plots at Aurora CC
are good, and it looks like the Proxy/Primo tank mixes will
give us the usual 70-80+ % control (first treatments were applied
April 5). For those of you who think you have some "break-through,"
ask yourself what the treated area would look like without the
Proxy/Primo treatments, or what a check plot would look like
if you had left one… You may still be getting 50-70% control,
but that may not be what you expected (?)…
Diseases:
A few "subliminal" circular patches have been showing
up on bent/Poa fairways and greens. In most cases these are
probably caused by activity of some cool temperature tolerant
Rhizoctonia fungi, but could have other causes such as a localized
dry spot/fairy ring, an early take-all patch, or possibly some
Microdochium patch. Also, of 'patch interest' to the southern
Illinois zoysia growers, we have heard early sightings of zoysia
or large patch in St. Louis. This patch is caused by Rhizoctonia
solani that likes to prey on zoysia when it first comes
out of dormancy and is growing slowly.
There has been a lot of interest in early (well
before first symptom development) dollar spot applications,
and we have just established some plots at Golf House to test
the viability of this application. The thought originated from
some previous tests by Dr. Joe Vargas and Dan Dinelli that implicated
some long-term effects of hitting the pathogen early in its
inoculum phase. Our initial application took place yesterday
and we are going to see how long it lasts until we have to make
a subsequent application. Another idea is to 'bookend' the first
dollar spot pressure period with fungicide applications 30 days
apart, so we are testing that as well. Looking at the current
weather forecast, we may actually be a little late in our tests
with the early application but we will see... Dollar spot prediction
models will probably go to orange or red if temps this weekend
hit the mid to upper 80s; the model went red several times in
April already for courses in central and southern Illinois (perhaps
indicating of things to come...).
Another question/comment that we frequently hear this time of
year has to do with off color patches of bentgrass in greens
and fairways, which is often blamed on "leaf spot."
We do not believe leaf spots or other fungal diseases cause
these patches, but instead it is a response of certain bent
clones to adverse environmental conditions. The adverse conditions
usually involve a recent hard frost (such as we had mornings
of Apr 11-14, and May 3), especially if combined with an abrasive
topdressing just before the cold spell. The adverse conditions
could also involve a sudden hot and dry weather pattern, or
a dry and windy pattern (e.g. last week of April). Another possible
villain could be a borderline "safe" herbicide application
(don't forget bents are sensitive to phenoxy herbicides). In
any case, we have never found a true Helminthosporium type leaf
spot on these ugly bent patches in spring, although the injury
may lead to minor leaf fungi infecting weakened plants -- and
might explain why some relief is often observed after a Daconil
type application. Get more information here
at one of the past turf tips or here
at Ohio State's Superintendent Korner.
Weeds:
Spring emergent broadleaves are everywhere, including
dandelions, clover and all kinds of mustard and wild garlic
(yum yum). Our computer model to time applications for crabgrass
preemerge treatments has been triggered for central Illinois
north to the I-80 corridor, based on accumulated soil degree
days (base 50 F). Questions and comments about moss control
are starting to come in; when the complaints reach a crescendo
we will expand our reporting, especially if there is anything
new (CPR treatments?).
Insects:
With the coming warm-up, we expect to hear of
black cutworm moths starting to fly around central IL, and perhaps
working there way farther north. We have some cutworm pheromone
traps out here at golf house, and will keep an eye out for winged
intruders. Also, Black Turfgrass Ataenius (BTA) adults have
been observed cavorting on greens in the Chicago and Rockford
area, so keep an eye out for these little black beetles showing
up in the mower baskets. Interestingly BTA adults are one of
the very few beetles that overwinter as beetles and not in the
larval stage, so they are the first to show up in spring. Actual
damage from the 1st generation of grubs is not expected for
many degree days now (1100-1160) but as May starts turning into
June we may have to pay attention to these critters.
+++++++++++++++++++++++
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
