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This is an abbreviated edition of the IPM Update for Illinois golf courses, for the last weekend of July 2000.
Cool and dry weather has continued for the past few days, so very little disease activity has been noted.
We are definitely starting to dry down surface zones of soil/thatch however, so keep an eye out for localized dry spot development or other signs of drought stress.
Some of you may actually have to run some irrigation cycles - hope there are no new leaks!!!
Weather Update
Forecasts for Sunday and Monday show hot and humid air entering northern Illinois for the first time (in earnest) in the year 2000.
A little different than last year mis amigos, eh???
(There were no recorded days of high temps over 90 degrees at O'Hare Station in June.)
We actually caught a nice break Thursday and Friday (and hopefully today) as a weak front dropped down from the north, which brought dryer air, cool temps and no rain to most of the already wet region.
The cool weather break was greatly appreciated by Ken Lapp and Frank Jemsek at Cog Hill.
The Western / Advil/ Tiger Open is in full swing, the course looks fabulous, is playing even more fabulous, and I encourage everyone to stop out and see the show.
Diseases
With the return of some humidity and daily high temperatures staying in the low to mid 80s, dollar spot will remain the disease du jour for the time being.
Hopefully, you have most of the symptoms under suppression for now.
I am sure we will have some significant problems going into late August and September.
If you are having trouble with dollar spot control after application of DMI fungicides, please let me know.
I will probably do some screening for increased fungicide tolerance in the lab this fall.
Anthracnose seems to be picking up as Poa annua and Poa trivialis head into summer stress periods.
If you start to see small, scattered spots of Poa turning off color (yellow to orange to reddish colors are possible) in distinct patches, look for signs of the anthracnose pathogen and fruiting bodies at the stem base or along the stem, or on leaf sheaths just above the crown.
Like dollar spot, anthracnose is favored by low N fertility, and the activity of fungicides can be improved by tank mixing some soluble N with a fungicide.
Also, I have seen anthracnose picking on patches of Poa triv, same as we have seen previously with dollar spot? Poa triv is pretty worthless, looks like to me?.
Unless you are overseeding bermuda greens down south?
Insects
Some damage from sod webworms continues to be reported, and feeding by Japanese beetle adults continues in infested areas.
I saw a very unusual insect problem this week in central IL.
An area of rough height grass between a green and the next tee (half an acre or more) was loaded with nests and adults of cicada-killer wasps, which were flying around in this location as thick as Japanese beetles.
These are really big and scary looking wasps, but they rarely sting humans (they sting cicadas!).
Needless to say, the lady golfers at this course wanted those bad-boys outta-there!
Weeds
With the cool and wet weather, I have seen lots of white clover (flowering no less - who spilled the popcorn on the fairways?), chickweed, and plenty of buckhorn and other plantains.
My yard is full of creeping charley (ground ivy) again, too.
Hope the weather stays sweet and we coast right into fall!!
Please let me know if disease activity picks up again first week of August?
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