Weather review
The last two weeks of August have turned much warmer and
more humid, as hot air from the southern plains states was
finally allowed to move into the region. Although the dew
points have been high, little rain has fallen over the northern
two-thirds of the state during this hot spell. In fact the
Springfield area is reporting only a quarter to half an inch
of rain for the month. Cooler air is forecast to move into
the Midwest region by the weekend and into Labor Day, hopefully
some droughty regions will get some rain from passing thunderstorms.
We have had few reports of turf injury (eg Poa decline)
or significant disease activity, even though this weather
pattern can be tough on turf. Since the warm-up is coming
so late in the season, most turfs are relatively healthy and
coming through the stress in good shape. Also, soil temperatures
are relatively low and the shorter days should help keep extreme
soil temps from developing. There have been significant increases
in localized dry spot (or “hot spots”) and fairy ring activity,
so keep an eye out for these problems and be sure to syringe
or hand water areas that are going under stress.
Diseases
Dollar spot, and to a lesser extent Pythium blight and brown
patch, all have been reported to be active across the region.
Although in most cases these diseases have not reached damaging
levels, perhaps due to the late arrival of the warmer weather
pattern. Dollar spot outbreaks have been reported, but temperatures
in the mid to upper 90s often slow this disease down again.
Leaf spots and anthracnose also continue to cause problems.
As stated earlier, localized dry spot, type I fairy rings,
and Lycoperdon puffballs on greens have become a problem
for the first time in Chicagoland this season. . Chemical
control is difficult because these problems can be caused
by an estimated 40-60 different types of basidiomycete fungi;
some of which are not susceptible to fungicides at normal
use rates, while others may be too deep in the soil to be
affected by the fungicide. The most effective chemical control
thus far has been applications of flutolanil (ProStar) with
a wetting agent. The DMI and QoI (strobilurin) fungicides
have also been used with some degree of success. Unless stated
otherwise on the label, water the fungicides in after application
to deliver them into the soil/thatch layer. For alleviation
of severe symptoms, it may also be necessary to aerify, irrigate
more frequently, use wetting agents, or mask the symptoms
with additional fertility.
Insects
Japanese Beetle adult activity has peaked in most of the
state. It appears that JB populations have been much lighter
this year than in recent past, but some areas were still pretty
hard hit. Hopefully, like the beetle population, the white
grub population will also be less than normal this year. White
grub activity has not been reported yet, but should be expected
and scouted for in early September.
Cutworms and sod webworms remain active and will continue
to be a problem for a few more weeks (as are the feeding birds)
on untreated areas. Mound building ants are an ongoing problem
as well, and we still seem to be searching for an effective
treatment – especially on greens. Some of the newer bait products
appear to have a lot of potential for control, but spreading
bait on greens mowed daily at 1/8” presents a problem….
Weeds
With the approaching cooler weather in September, it is time
to start spraying broadleaf weeds again for autumn control.
Some examples of persistent problem weeds include: clover,
black medic, knotweed, spurge, purslane and chickweed. Moss
and algae reports continue to roll in. We have had some good
moss control results in small test areas with a “tank mix”
of 4 oz / gal of Ultra Dawn and a tablespoon of baking soda
(predissolved in warm water before mixing). We are going to
further adjust rates of both the soap and soda in the mix
to see if some potential tip burn on foliage can be avoided.
