GOLF: What preemergent herbicide do you apply to creeping bentgrass greens for annual grass control (not Poa)?

Dithiopyr (i.e. Dimension)
Bensulide (i.e. Bensumec)
Pendimethalin (i.e. Pendulum)

Update (5/21/2013)

Rhizattackin' both warm and cool season grasses

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Higher temperatures and a significant storm over MO in the last 7 days.

Most areas in Missouri received 1.5 – 2 inches of rain from the catastrophic storm that originated over Oklahoma, with some locally heavy rain amounts such as St. Charles, MO that received 2.5 - 3 inches.  There are some incredible videos on the web of the tornado, but this satellite imagery of how fast the storm gathered just seems incredible.  Condolences and prayers go to all those involved. 
Areas that missed the locally heavy downpours have near normal precipitation for May, except for the Bootheel, which is once again dry and 2-3 inches below normal.  Warm temperatures showed their face for a 7 day span to precede the storm, and soil temperatures are currently at their highest of 2013.  Temperatures are forecasted to go mild again, and only max in the 70’s over mid Missouri going into next week.  There is some chance for scattered storms over the weekend though, which hopefully will hold off for John Cunningham, staff, and volunteers at Bellerive Country Club as they host the Senior PGA Championship.  The course and facility looked fantastic last week during my visit, and should provide a great test for my old favorites Larry Mize, Curtis Strange, Hale Irwin, Tom Kite, Tom Watson, etc etc…  

Soil temperatures are at their highest levels in 2013.

Quick Hits

  • The Survey Says…  You may notice above a short radio button survey regarding pre-emergent herbicide choice on golf greens.  I’ll be changing this survey for each report in an effort to gather information on common maintenance practices, and perhaps identify areas to pursue in future research.  The questions will rotate between golf, sports turf, and lawn focus areas, and don’t worry the answers are anonymous (I’m not the IRS you know).  I appreciate your participation, and the live results should also allow you a glimpse into what others may be doing.  Hopefully making it a win-win…  If you have any survey questions you’d like to see, feel free to submit them to me.  

    First symptoms of brown patch in tall fescue.
  • As reported last time, large patch is still firing throughout the state (just had a report from Springfield MO yesterday).  With this brief uptick in temperature, large patch’s counterpart on the cool side, brown patch, is now joining in on the fun.  In a scouting run yesterday around the MU turf farm, characteristic tan lesions with dark brown margins were easily found in our stands of tall fescue (see above).  Full decline of patches, which is observed as straw colored areas 1-3 feet in diameter, is not apparent yet, but the lesions are an indication that the monster has been awoken.  Cool temperatures this week should suppress activity of the brown patch pathogen (i.e. natural fungicide), but the next warm-up could really launch this disease into high gear.  Do not fertilize higher-cut cool season grasses now, unless you really want to bring out this beast.    

    First symptoms of dollar spot in inoculated areas of MU turf farm.
  • Last Friday, the first initial infection centers of dollar spot on creeping bentgrass were noticed.  Yesterday, they were confirmed, and today they are growing in number.  These outbreaks are on both greens and fairway height areas being utilized for fungicide evaluation trials that were artificially inoculated on 5.13 - so the background inoculum load is high.  However, this does show that the environment is conducive for dollar spot development, and preventive measures should be taken.  If anyone else in the region is noticing dollar spot activity, please send a quick email and give me a heads up.   

    Spring dead spot symptoms very apparent now that bermuda is greening up.

  • Bermudagrass is greening up around the farm, which is making spring dead spot painfully apparent.  This soilborne pathogen takes advantage of bermudagrass when it goes into fall dormancy, and infects roots, rhizomes and stolons.  As the above picture shows, encroachment by cool season broadleaves or annuals (like Poa) can be a significant problem in the opened up patches.  The bermudagrass eventually recovers slowly by late June or early July, but the unsightly areas on sports fields can disrupt uniformity and raise injury potential.  This summer, Dr. Brad Fresenburg and I will be installing a new NTEP trial evaluating the newest bermudagrass varieties (like ‘Latitude 36’ shown greening up early above).  Unique to this study and our location, however, we are being allowed to inoculate these varieties with the spring dead spot pathogen after they are established.  Currently, there is a paucity of information on spring dead spot resistance in bermudagrass varieties, and we hope to shed some more light on the topic over the course of the study. 

MU Graduates & A Taste of Sports Turf

Preparation for 2013 softball regional tournament

Dr. Fresenburg and the MU athletic fields crew of Josh McPherson and Jerry Cummings invited me to help with preparing the softball field for the 2012 and this current 2013 set of softball regionals.  I’ve had very little previous experience with field preparation, and this experience has opened my eyes to the wonders of infield clay and pitching mound reconstruction.  Jerry and the softball crew do an amazing job, and the field looked great for the ESPN cameras and played great for our Mizzou softball team…  who advanced to play the Washington Huskies in the Super Regionals this Thursday and Friday. 

The experience also gives me the chance to interact more with our students who are interning with the fields crew, and see them in action.  I knew that Dr. Fresenburg had built a strong STM program, and it’s readily apparent when you observe them work as a team.  Three current students are on their way to high profile internships at Fenway Park – Red Sox (Garrett Maxey), Miller Park – Brewers (Jonathan Palmer) and Ralph Dean Stadium – Jupiter, FL (Alex Politte).  We wish them luck this summer as they build their careers.

I’d also like to take a moment to congratulate and recognize our outgoing Turfgrass Science graduates Ben Kraemer, Stephanie Kincannon, Sam Fairchild, and Erin Casey.  Ben and Sam have been regular interns on the sports turf crew, Stephanie is a previous Lobenstein Scholarship Award winner, and both Ben and Erin will be going on to pursue their Masters degree.  It’s a great graduating class - I’m glad to know them, and I’m certain they will be successful.         

Field Day, July 30th – Save the Date.

The previous article is a great segway to mention field day again, as one of three prime afternoon tours will be visiting with Josh McPherson to discuss the ongoing and upcoming changes to the MU athletic facilities.   Exhibitor/vendor registration is now open, and attendee registration will be open soon.  Hope to see you there. 

Field day talks include wetting agents, tree care, lawn care, and disease updates.


Have a good week. 

Lee Miller
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Extension Turfgrass Pathologist
University of Missouri