Turfgrass Management Agriphone for June 7, 2010

Past weather and the forecast for the upcoming week

Last week we saw a break in the hot and dry weather.  The rain last week was desperately needed as the non-irrigated turf was drying out and wilting in many areas. The turf did not come out of that hot, dry spell unscathed.  It appears that dry, hot conditions at this time of year (spring) cause more damage to turf than they do in the summer.  The turf did not have a chance to acclimatize to the heat or the dry conditions.  Turf that was dry was starting to go into dormancy and was turning brown.  There are symptoms of direct heat injury from mower tires, golf cart tires, etc. driving on wilted turf.  The rain has left behind large areas of yellow turf, streaked yellow turf (from tire tracks) and small yellow spots where these dry areas and heat injured areas were.  These have been misdiagnosed as disease (Pythiumblight), localized dry spots and insect damage.  What isn’t clear, is how much recovery there will be.  My gut feeling is that with all the recent rain there is more than sufficient soil moisture now and most of these areas will slowly come back, but it may take longer than expected.  If the direct heat injury was severe, there may be some areas that don’t come back.  Only time will tell which of the areas were the most severely hit.

It is a chilly start to the week.  It is 13ºC in Guelph right now. Temperatures and humidity will start climbing and it is forecast to be in the high 20’s by the end of the week.  The first half of the week will be ideal temperatures for growing turf, but the later part of the week and the steamy weekend will put some stress back on the turf.

Disease activity 

Dollar spot did arrive, but it hasn’t had a big flare up yet.  I think the weather was just right, then too hot and now it is too cold.  There have also been some reports of anthracnose foliar blight during the hot spell.  It will have stalled at the moment with the cool temperatures.  One thing that we are seeing a lot of at the moment on golf greens are mushrooms.  After the rain, there has been an incredible flush of mushrooms coming out of the aeration holes on the greens here at GTI.  The GTI Turf Diagnostics has received samples with Pythium root dysfunction, some samples with runner hyphae showing very early infection from summer patch, but no symptoms yet, and Waitea patch over the last week.  If you are encountering diseases that you can not diagnose, please send a sample to the GTI Turf Diagnostics.  You can email them at  diagnostics@guelphturfgrass.ca or telephone them at (519) 824-4120 x 58873.

Annual bluegrass weevil, BTA and other things insect-like

We are approaching the period where you may see damage from annual bluegrass weevil.  There were definitely two waves of adult migration this spring and damage from the first wave of adult migration should be showing up soon.

Still lots of turfgrass ant activity.  Research has shown that treating the periphery of the green and a 10m swath just outside the green is an effective spot treatment for greens that have an ant problem.  Dr. Harry Niemczyk has a good article on the turfgrass ant behaviour and its control.  Be aware, however, that many of products that he recommends are not available to us in Canada at this time.

After all the rain this week, the starlings are having a field day feeding on leatherjackets.

Grubs are showing signs of pupating.  I haven’t seen as many June beetles this week.  Just a reminder that currently, there are no insecticides registered for control of June beetles in Ontario.

For products registered to control insects on turf in Ontario refer to OMAFRA Publication 384, Turfgrass Management Recommendations.

Weed control products 

Fiesta™, the new iron chelate has been available for several weeks now.  I have had a chance to do some weed counts this spring on plots that were treated with Fiesta™ last fall.  It appears for the dandelions and black medick, that there is considerable re-growth of these weed species, back to similar levels before treatment.  In the fall, Fiesta™ was only applied once to the plots and it may be that at that time of year, two applications are necessary.  There are more research trials being conducted this spring at GTI to try to get a handle on the re-growth of broadleaf weeds after treatment with Fiesta™.

More Sarritor is being applied now. If it was applied late last week, the weather has been cooperating with all of the rain and cool temperatures this weekend giving the ideal conditions for Sarritor.

Fertilizer applications

We are still in the ideal window for that first spring applied fertilizer application.  Remember that fertilizer is one important tool in your tool box now that we have fewer choices of herbicides.

– See more at: https://lawnsavers.com/turf-hotline-2010/turfgrass-management-agriphone-for-june-7-2010.html#sthash.51d7uWBN.dpuf