RUST DISEASE SHOWING UP IN NORTH CENTRAL IOWA

Nick Christians
September 24, 2012

Here are some pictures of rust disease on Kentucky bluegrass submitted by Damian Richardson, Landscape and Conservation Specialist from Alden, IA.  Rust is caused by fungi in the genus Puccinea.  It is common on Kentucky bluegrass and other grass species in Iowa, but there has not been a lot of it so far this year.  It usually begins to show up about the first of August.  This is the first report of it that I have received this year.  This one was on September 20.  These are some good closeups of the rust pustules on the individual blades of grass.  Thanks for submitting them Damian.

While there are several fungicides that will control rust, I usually do not recommend chemical treatment unless it is on a critical area.  It is usually a sign of relatively low nitrogen.  Just add a little nitrogen and mow regularly and the problem should run its course and disappear.  Some cultivars of Kentucky bluegrass are more susceptible that others.  If it is a continuous problem each year, you may want to kill the existing cultivars with Roundup and replace them with more tolerant varieties.  For information on which varieties show tolerance of rust, see the National Turfgrass Evaluation (NTEP) web site at  (http://www.ntep.org/).  They have data over several years on rust infestation of many cultivars of Kentucky bluegrass.

If anyone else is seeing a lot of rust, let me know.

MORE BERMUDAGRASS IN IOWA

Nick Christians

September 18, 2012

Since I put up the post on August 2 about bermudagrass in Iowa, I have had several other calls about bermudagrass invading lawns and sports fields.  These calls have come from Burlington, Council Bluffs, Des Moines, Keokuk, Davenport, and Red Oak.  I have also been getting samples to identify.  I have had more contacts on bermudagrass in the last 8 weeks than in the previous 33 years combined.  The mild winters and hot summers are resulting in this species becoming a significant problem in some regions.

The usual questions is, “How can I kill it?”.  There is no selective control in cool-season turf.  You have to kill it with Roundup.  It is very hard to kill.  It will likely take several repeat applications of Roundup, and even then, its extensive rhizome system results in regrowth.  Complete soil sterilization with methyl bromide may be the only sure way to remove it from critical areas like sports fields and sod fields.  Of course a couple of cold winters would also take it out.  That is the reason it was not here before.

Here are some pictures that I received from Eric Van Ginkel of the Iowa Cubs concerning the Dowling High School softball field.  The sodded this field just 5 years ago with Kentucky bluegrass and bermudagrass has spread extensively in the last couple of years.

If anyone else has a major infestation, send me some pictures and I'll get them up on the blog.

Figure 1.  The Dowling softball field.  This are the biggest patches of bermudagrass that I am aware of in Iowa.

Figures 2 and 3.  Eric wrote that these patches were discolored by an herbicide.  He did not say which herbicide, but it looks like tenacity.

Figure 4.  The extensive stolons of bermudagrass.  This is what makes it spread so fast.

AERATION AND ROOTING

Nick Christains
September 7, 2012

Here are a couple of pictures from Eric Van Ginkel, who works for the Iowa Cubs.  He also works on several other sports fields in the Des Moines area.

This was a field that had highly compacted soil following construction.  They sodded it last fall with Kentucky bluegrass, but the sod had shallow roots and grew slowly because of the compaction.   This spring, they deep-tined the area with solid tines.  The area improved.  They recently used hollow tines on the deep-tine unit to pull cores.  These pictures show the rooting into the holes from the solid tines in the spring in cores that were removed this fall.

This is something that I have observed as well on area that have been deep-tined with solid tines.  It is amazing how much root growth can occur in these aerification holes.  We will need to do a follow up in the spring and see how much rooting there is into the holes left by the hollow tines.

ANOTHER GRAY LEAF SPOT WARNING

Nick Christians
September 4, 2011

A year ago, on August 31, 2011, I put up a post warning about Gray Leaf Spot on perennial ryegrass.  This disease shows up rather infrequently in Iowa, but it does occur around Labor Day on years when temperatures are unusually high.  Last year's Labor Day temperatures were in the 90's and if you check the post from September 19, 2011, you will see that it did occur on several golf courses with perennial ryegrass fairways.

This disease is caused by the fungi Pyricularia grisea. It seems to selectively hit perennial ryegrass on intensely managed areas such as golf course fairways and sports fields. Under the right conditions, it can be more devastating than Pythium blight. When it hits, it can wipe out large areas of turf overnight.  Fungicides, such as Banner/Daconil will control it, but they must be applied before the outbreak.  Once the disease begins, it is too late to apply.

The reason I bring this up is that we are in the same weather pattern again this year.  The disease does not always occur when its hot around Labor Day, but it did last year and I would watch for it this year.

The pictures below were taken in 1998 on Willow Creek Golf Course in Des Moines and last year on Cedar Poine golf course in Boone. The dead grass is perennial rye and living grass is Kentucky bluegrass.

If anyone has an outbreak of Gray Leaf Sport this year, let me know and send some pictures. 

SPECIAL SPEAKER AT TURF CLUB WEDNESDAY AUGUST 29

Nick Christians

August 27, 2012

We have a special speaker at the turf club meeting this Wednesday, August 29 at 6 pm in room 118 Horticulture.  He is Mark Kuhn, who worked at the Wimbledon Tennis Tournament this summer.  He will be talking about that experience and about maintaining Iowa's only grass tennis court on his farm near Charles City.  Everyone is welcome.

The information below is a press release on the event.

Iowa State University
College of Agriculture and Life Sciences

8/22/12

Contacts:

Nick Christians, Horticulture, (515) 294-0036, nchris@iastate.edu

Melea Reicks Licht, Agriculture and Life Sciences Communications Service, (515) 294-8892, mreicks@iastate.edu

Owner of Iowa’s Only Grass Tennis Court to Speak at Iowa State Aug. 29 about Wimbledon Internship

AMES, Iowa – Mark Kuhn, a farmer and Iowa State University alum, will share his recent experience as a Wimbledon intern in a presentation on campus on Aug. 29.

Kuhn, of Charles City, is the owner and caretaker of Iowa’s only grass tennis court.  

He will present, “My Experience at Wimbledon” at 6 p.m. in room 118 Horticulture Hall at a meeting of Iowa State University’s Turfgrass Club.

  

Kuhn will discuss his recent internship working with the grounds staff at the All England Lawn Tennis Club. Kuhn spent eight days learning from the grounds staff prior to this year’s Wimbledon Championships. He will share pictures and behind-the-scenes stories about how the lawns of Wimbledon are prepared for championship play.

  

Kuhn and his family built Iowa's only grass tennis court in 2003, the All Iowa Lawn Tennis Club, on a cattle feedlot on their farm after consulting with Iowa State University horticulture professors Nick Christians and David Minner.  

Kuhn will discuss how he built and maintains the court, and the role the court played in his receiving an invitation to intern with the Wimbledon grounds staff.

  

Kuhn grows corn, beans and bentgrass on his family's farm near Charles City. He graduated from Iowa State University in 1973 with a degree in history. Kuhn served as a member of the Iowa House of Representatives from 1998-2010. He is currently a member of the Floyd County Board of Supervisors.

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Editor's Note: Photos of Mark Kuhn at Wimbledon and of his grass court near Charles City are available upon request. Contact Melea Reicks Licht at mreicks@iastate.edu, (515) 294-8892.  

On the Web: This and all other Iowa State University College of Agriculture and Life Sciences news releases and related photos are available at http://www.ag.iastate.edu/news/.

_______________________________________________
Iowa State University
College of Agriculture and Life Sciences
Communications Service
304 Curtiss Hall
Ames, IA 50011-1050
(515) 294-5616
Web: http://www.ag.iastate.edu
Facebook: http://www.facebook.com/IowaStateU.AgLifeSciences
Twitter: http://twitter.com/iastate_cals

Figure 1.  Mark at Wimbledon

 Figure 2 to 4.  Pictures from Mark's tennis court in Iowa.