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Bacterial Wilt of Bentgrass...

I am posting this an "emergency post" since we are all getting a lot of phone calls about it. This message is from Dr. Nathaniel Mitkowski at the University of Rhode Island. Dr. Mitkowski is an expert in bacterial wilt of annual bluegrass.

Bacterial Wilt of Bentgrasses (by Nathaniel Mitkowski, Ph.D.)

The first time bacterial wilt was identified from bentgrass was in the 1970’s. The pathogen, Xanthomonas translucens pv. graminis, only seemed to infect the Toronto C15 variety. This variety was planted primarily around the Chicago area and could rapidly kill turf. Since then, this bacterial species had been sporadically identified but has not been observed causing much damage. In 2003 I found the pathogen in Pawtucket, Rhode Island but it was essentially nonsymptomatic.

In June of 2009, a new bacterial wilt was identified on Penn G2 greens at [Golf Course name removed for confidentiality} North Carolina. The pathogen caused severe etiolation of leaf blades. The isolated bacteria was identified by Dr. Joseph Vargas at Michigan State as Acidovorax avenae subsp. avenae and resulted in wilting and senescence of plants when inoculated in the laboratory. Reports from [golf course] this summer indicate that the bacterium is still causing problems and some turf is being lost. The first report of the pathogen can be found here:

Bacterial Wilt on bentgrass from Dr. Vargas

In the past week, bacterial wilt of bentgrass has been identified at the URI Disease Diagnostic Laboratory at least a dozen times. The bacterium has been identified on L-93, SR1119, and velvet bentgrass. Reports of the pathogen on A4 have also come in. The disease will likely go to any variety of bentgrass. Symptoms include: etiolation, small to medium sized patches of weak turf, turf with excessive senescence and dead plants.

While etiolated turf has been identified from New England golf courses in the past, I have never been able to isolate bacteria from previous samples. The samples I am observing this year are full of bacteria at levels that I have not seen in the past. It seems highly probable that this bacterium requires extended high temperatures and humidity, weather common to the Southeast and similar to the weather pattern experienced in New England over the past 2 months. Superintendents who described seeing this disease in previous years mention that it often goes away completely when daytime temperatures drop into the 70 degree range. It does not appear that a break in the weather is imminent but if it occurs, plant recovery should follow.

14 Responses to “Bacterial Wilt of Bentgrass...”

Anonymous said...

I'd be curious to know how many cases of bacterial wilt have you found in the southeast? I've only heard of the one in Charlotte but it would be nice to know if there are more?

John Kaminski said...

To my knowledge, I have only heard of one case and the report from the Northeast may be creating more fear than needed. Again, this is all new to us and I am still not convinced that this bacterium is the primary cause of all of the may just be a contributing factor.

My understanding is that it is NOT widespread in the South, but perhaps Lane or Brandon could address what they are seeing.

These types of findings always come with about a million people thinking that they now have the problem when in fact it could just be something else like physiological, mechanical or stress-related problems.

Sorry for striking fear in so many with the post, my intention was to at least get the information out there.

Joey Young said...

That is a very interesting post. Do you have any pictures of the symptoms seen with the bacterial wilt? Keep up the good work!

Jerry Kershasky said...

As of yet no bacterial wilt on our 2 year old Penn A-1. When I had Toronto C-15 I would have out-breaks on and off throughout the summer, worst being right after a hot humid period when high pressure moved in with a sunny sky and low dew point the lack of functioning roots really showed.
Brookfield, Wisconsin

Anonymous said...

A golf course in the Southwest has just had its greens diagnosed with bacterial wilt. It first appeared only 10 days ago and has quickly spread resulting in a temporary closure of the course to attempt to alleviate the situation.

Lane said...

Seeing bacteria in bentgrass is a lot like seeing an anthracnose spore on Poa or a Curvularia spore on bermudagrass. There is always a lot of it there on stressed or dead turf.

Unless someone has identified the bacteria that is present in your sample and demonstrated it to be pathogenic to bentgrass, then a diagnosis of bacterial wilt is meaningless.

Anonymous said...

It has recently been published that at least a dozen courses in the Southeast have had this issue, and probably some unreported. I have seen this issue first hand. I suggest John Kaminski do a little research before dismissing the idea that there may be something he does not know about, or believe!

Anonymous said...

Published where?

John Kaminski said...

It's always great when we have "Anonymous" people who are willing to call me out from behind the curtain of anonymity.

To address the comment, however, it is again not my belief that this isn't a potential problem, but I am not willing to jump on a bacteria bandwagon without concrete evidence.

There is a protocol for determining this and despite some people dealing with these symptoms for several years now, no one appears to be able to get a handle on the cause. Have I seen bacteria associated with these symptoms? Yes, but only in a handful of the samples and not in all of the symptomatic tissues exhibiting symptoms. So again, I say that yes there could be an association but I'm still not ready to call it a cause and effect.

If you don't like my opinion, then you don't have to listen to me. Trust me, you won't hurt my feelings.


Anonymous said...

I me the hard evidence. I have been in the turf business for 27 years. If it is going to be science I expect it to be proven before everyone starts making all encompassing claims that that is the reason their turf is dying.

easternshore said...

The U of Maryland has recently diagnosed Bacteria Wilt on the greens at The Easton Club golf course in Easton, MD (a Uof MD Foundation owned course). We have been told it has to "run its course". Is that true and what can prevent this condition in the future, or once there - always there? Greens are really unplayable.

cindy said...

I was hoping you could answer Easternshore's question. Also can it be transferred on shoes?

I have been diagnosed with bacteria wilt 2 weeks ago in NW Missouri with a soil sample I sent to U of Missouri. Things have started to decline with temps over 100 for the past 8 days and 2 more to fo before we expect a cool down ( low 90's ). Last week I applied ZeroTol at 12 oz per 1000 on 3 greens. This was 3 applied 3 days in a row right after we cut. Today is day 4 since 1st app. I do see things getting better but I'm waiting till Monday to apply to rest of the greens. This morning I'm applying Dac action and Signature at high rates. Dr Miller from UofM was here yesterday and recommended this combo if fungicides.
Things that have helped out for me. Mowing at night is a must. If you mow in the morning it spreads throughout the green and even to other greens. Also raising the height ( I'm at .180 ) and mowing every other day helps also. Green speed is slow but slow greens are better then dead greens.
If a case is only on a green or a few greens, designate a mower for those greens only. Also use a 10% bleach solution on the reels after you now each green. This prevents spread to other greens.
In the Chicago are reports have said Primo is not helping things. In some cases its caused bad problems with the bacteria. Todays application will have no primo for me. Also taking out the N and adding FE to the mix. Feel free to email me ,, if you have any questions. I have a lot of pics if you wanna see what it looks like.

Anonymous said...

Id like to see some pictures.

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