[TEPaul]

What is it specifically?

Is it some old agronomic nemeses masquerading under a new name or has it been around with that name for a while?

I've heard more than a few times it may be the next big problem bent grass managers may have to deal with in the future.

If so, what is the latest thinking out there right now about how to deal with it or better yet prevent it?

And lastly, what sort of conditions seem to promote it if anyone has even thought that far yet?

[Tom_Doak]

Tom P:

If I remember correctly, "bacterial wilt" was what they called it when the cultivar known as Toronto creeping bent, or C-15, started going away on golf courses in the midwest in 1985-86.

The cure was to re-grass with a variety other than C-15 ... I don't think they ever solved the "bacterial wilt" problem, whatever it is.  So, if you are hearing the term come up again, you can expect a bunch of courses to be reseeding or even rebuilding their greens this fall.

[Ronald Montesano]

Odd, from my recollection, it had to do with a certain basketball player with a penchant for spreading his love disease...

[TEPaul]

Ronald:

THAT is beautiful. I wish you could've seen me when I first read that. Well, then, whatever Bacterial Wilt is let's hope it f...s the turf of something less than 10,000 golf courses which is my recollection of the number of woman Chamberlain said he nailed when he wrote that.

I mean, Jeez, just do the math; did the man ever sleep or were his lies about as out-sized as he was?

I remember seeing him bellying up (in his case kneeing up) to the check-in counter at Skipol Airport in Amsterdam. All the Dutch were whispering and giggling with stuff like "Look at that Shvartz" (or whatever it is they call black people). I've gotta admit he was definitely the tallest human being I ever saw in my life, and by a lot.

[Ronald Montesano]

They didn't call him the human vuvuzela for nothing!

[Roger Wolfe]

And I quote the USGA (I think):

"The #1 fungicide on the market today is a fan."

[Ian Larson]

It's been a recognized disease since like the 60's or 70's I think. It's one that just like other diseases will pop up when the strain of bacteria is present, wet conditions and high temperatures. I've seen it in college while working in South Carolina but never since. If it's made it's way up to the northeast just like the southern weather conditions did I'm sure there are some cases where Bacterial Wilt is one of the culprits. Tom is right, it did go after a certain bentgrass years ago and I don't think they have been successful in isolating the strain of bacteria that causes it so they can formulate appropriate fungicides. I'm sure there are some than are effective and on the market but the best defense against Bacterial wilt is keeping your greens dry and not giving it a chance to innoculate the grass plants.

Rogers post is spot on. When nature goes crazy with the rains and temperatures the only thing to do is try to use technology to gain back some control...like the fans and SubAir sytems. Keeping the greens cool and dry is the biggest thing.

[TEPaul]

Ronald:

Are you saying that Bacteria Wilt is the agronomic vuvuzela of our future?

I don't care if you answer that or not because if anyone asks me what Bacterial Wilt is I'm gonna tell them it's this agronomic vuvuzela which  is quite terrifying to behold and consider. If they ask me what the hell an agronomic vuvuzela is I'll just tell them to visualize a giant black disease that can f.... about 20 golf courses all in the very same night and can even dunk basketballs with amazing ease.

Look, Ronald, will you just shut up and stop making me laugh as well as making me make posts like this? This might be serious business for the future of the turf of our golf courses. 

[Ronald Montesano]

I'm done...I use comedy to mask ignorance, which is why most of my posts are so damned funny.  By all means, Roger, Tom, et al., continue this discussion, as it is really interesting to me.

[Bradley Anderson]

The bentgrasses that were selected from samples of the best south german bent greens in America, and planted in the USDA gardens, were subsequently cloned for commercial propogation. They were wonderful grasses because they were so uniform - each plant being an exact genetic progeny of the original mother plant.

But those species had no genetic variation in them, and they were the perfect host for bacterial wilt. Once the bacteria infected a small section of the green, it spread from plant to plant with no resistance. Much in the same manner that Dutch Elm disease worked - the American Elms were cloned too.

The bacteria filled the vascular system of the plant, choking the supply of water from the roots to the leaves, and the plants died from wilt. C-15 was especially vulnerable.

Whenever you cut C-15 at an 1/8th of an inch or lower it became especially vulnerable to attack from the bacteria.

The newer varieties of bent are bred from as many as 20 parent plants, so there isn't much possibility that a bacteria will ever take those plants out.

[Bradley Anderson]

We had dinner with Dr. Vargas last week and he talked briefly about bacterial wilt in reference to the issue of planting more than one variety of grass on greens.

Dr. Vargas was the one who isolated the bacteria from infected leaves at Butler National - the first major club that was attacked. Anyways, he stated that the newer bents should never be in danger of a pathogen like bacterial wilt because they have so much genetic diversity bred in to them. And there you have it - planting more than one variety of bent on a green isn't necessary from a bacterial wilt resistant stand point. However, there are many other pathogens that could attack one specific variety more so than another, so it might be a good idea to plant more than one variety.

[TEPaul]

Guys, particularly you supers out there, this is good stuff you're putting on here. I was just speaking with Donnie Beck (Fishers Island) about this, and I mentioned to him for you guys to please appreciate how much some of us on here are real agronomic laymen when it comes to the business and science of what you guys know and do.

For instance, I don't even really know the difference between fungi and bacteria.

Could you guys please back up and explain some of those fundamentals and basics to some of us before you go on with the more scientific and technical explanations if most not in the business on here are as much the uninformed layman with agronomics as such as I am?

Thanks.

PS:
I don't know how you guys in the golf grass business do what you do with all that's going on out there these days from every direction. I, for one, have a lot of admiration for you people in your line of work.

[TEPaul]

"Anyways, he stated that the newer bents should never be in danger of a pathogen like bacterial wilt because they have so much genetic diversity bred in to them."



Bradley:

Please explain to us laymen what genetic diversity actually means to a plant's ability to withstand various problems, perhaps even including what has happened to some courses this summer that seems to be called not Bacterial Wilt but Wet Wilt.

[Donnie Beck]

A couple of good links.

http://www.umassvegetable.org/soil_crop_pest_mgt/crops/documents/BacterialWiltFactsheet.pdf
 
http://www.golfdom.com/turfgrass-maintenance/disease-control/dealing-with-bacterial-wilt-poa
 
http://www.turf.uconn.edu/pdf/research/factsheets/Disease_Bacterial_Wilt.pdf

I will try to post more later.

[Bradley Anderson]

Tom,

Wet wilt is not a pathogen, rather a physical phenomena of submerged plants that can't cool themselves because the root systems have been oxygen deprived for so long that they loose their ability to take up water. I'm not aware of any turf breeder that has bred plants specifically for that situation.

Technically speaking, I'm not sure if bacteria wilt can be classified as pathogenic. Pathogenic organisms are fungal, whereas bacteria are - - - nasty little microscopic critters. Basically bacterial wilt is like clogging of the arteries. Once those critters set up shop in the vascular system of the plant they begin to multiply so quickly that they fill the entire artery until water can't pass through.

Now this issue of turf genetics is critical to our understanding because, as I have said on here before, you cannot coax a plant into performing beyond its inherant genetic attributes. There are those who think that depriving a plant of water and nutrients will somehow help it evolve into a stronger species. I think that is very naive to expect that.

It can happen like this with Poa annua, but that's about an 80 year process of natural selection. Poa has dominate and recessive genes. If 2% of the annual seed crop bares the recessive traits of the genes, and if by chance those plants just happen to prefer being cut lower than the mother plant can tolerate being cut, then those seeds have a chance of germinating and growing up to produce more seeds and more plants that like being cut short. But even for all this to happen there has to be a deliberate environmental conditioning taking place. This is why we have some remarkable Poa annua greens on the older golf courses. But they didn’t get that way overnight.

[Bradley Anderson]

The older bents were selected for their ability to produce a uniform putting surface at 3/8's of an inch cut. As it turns out they were remarkably adapted to being cut much lower than that, but only to a point.

At 3/8's those bents had 5-7 leaves per shoot. At 2/8's they had 3-5 leaves per shoot. But at an 1/8th they can only set 2 or maybe 3 leaves per shoot. And that's why they lost the battle with Poa annua. They couldn't produce enough carbohydrates to compete because they lost so much vital leaf surface.

 

[Doug Siebert]

Bradley,

How feasible would it be to transplant those naturally selected poa annua strains with the 80+ years of breeding and conditioning?  Given that poa plants produce seed heads rather quickly, it sounds like closing a course for a day or two would be enough to have all the greens producing seeds.  Could you collect those and use them as a starting point to create a strain that would allow a course to seed new/rebuilt greens with quality poa, without enduring 80 years of crappy afternoon play waiting to evolve your own grass?  Perhaps they'd be rather specific to the area, so a strain originating in Monteray may be worthless in Oregon, but still...

[Bradley Anderson]

Doug,

I'll tell you in 3 or 4 years. 

There is a nursery outside of Pittsburgh that sells a product called Oakmont sod. It has been developed from aeration plugs that were taken from the greens at Oakmont.

I have a nursery growing now that is built out of Oakmont sod. I have been catching clippings when it seeds and scattering them on greens. I figure it can't hurt anything.

[TEPaul]

"The older bents were selected for their ability to produce a uniform putting surface at 3/8's of an inch cut. As it turns out they were remarkably adapted to being cut much lower than that, but only to a point.

At 3/8's those bents had 5-7 leaves per shoot. At 2/8's they had 3-5 leaves per shoot. But at an 1/8th they can only set 2 or maybe 3 leaves per shoot. And that's why they lost the battle with Poa annua. They couldn't produce enough carbohydrates to compete because they lost so much vital leaf surface."



Bradley:

Isn't that essentially the primary reason that is driving this train toward more and greater train wrecks-----eg the ever shorter mow heights in the name of increased speed or whatever?

Are you saying that if this factor (mow heights) alone could be globally pulled back some that THEN the grasses we know and use would have a far better chance of withstanding on their own these complex natural weather occurences that gets thrown at them with a mid-summer like this one being one of the best examples in memory?

To me there is a sort of poetic natural irony going on here, because as I said to you last night, given the recent consistently acheivable greenspeeds like 11-13 (basically never really done before from club to club as now), we really are in a realm of physics that takes playability to a far more complex factor----eg probably far too much really.

The irony is even if the surfaces we play on were not natural but artifical an actual stimp measure of 11-13+ would be too much for reasonable golf "playability" anyway given the slopes and contours of the kind of surfaces we really do enjoy most!

[Ian Larson]

I don't think height of cut has anything to do with greens being more susceptible to it because they are mowed lower. The perfect disease trifecta is presence of pathogen, moisture and the correct environmental conditions. Height of cut is not included in that. Although one exception is with anthracnose. A grass plant could be innoculated with bacterial wilt, wet wilt or pythium if it were at 6". It's just the perfect storm with the disease triangle and if a certain grassplant is susceptible to whatever pathogen is lurking around.

[TEPaul]

But Ian, given what you just said about mow height, what do you make of what Bradley said---ie:

"At 3/8's those bents had 5-7 leaves per shoot. At 2/8's they had 3-5 leaves per shoot. But at an 1/8th they can only set 2 or maybe 3 leaves per shoot. And that's why they lost the battle with Poa annua. They couldn't produce enough carbohydrates to compete because they lost so much vital leaf surface."


Doesn't the significantly reduced vital leaf surface make those bents far more susceptible to some kind of lack of endurance for various reasons----eg disease, natural conditions like this wet wilt thing that may've been the initial problem with HVGC's recent turf situation?

[Bradley Anderson]

Tom,

My reference was to C-15 and the relationship between it and bacterial wilt. C-15 was one of the original USDA Garden grasses that was bred to be maintained much higher than 1/8th. But when you dropped the mowers below that it would become vulnerable to  attack from these bacteria.

Now that was just that one species of grass. I don't think it is fair to say that low mowing is the causal factor behind bacterial wilt effecting other grasses. It could be other factors.

When the C-15 greens at Silver Lake were hit with bacterial wilt, an enterprising young superintendent drove his pick up overe there and harvested the sod right off the greens and laid it on his tees. At the higher tee cut the C-15 actually rebounded from bacterial wilt and it did jsut fine. Pretty ballsy. Those were some of the finest tees anywhere. By the way, that young superintendent eventually went on to Shoreacres to make it one of the best clubs in the cournty. 

[TEPaul]

Bradley:

By the way, when do you think the first C-15 was developed by the USDA?

[Bradley Anderson]

Tom,

In 1936 it was selected from a green at the Toronto Golf Club in Ontario and taken to be grown at the Arlington Turf Garden. I have always been told that the "C" and the "15" represent the section of the garden where it was grown under observation. There were 30,000 sq. ft. of plots being maintained like putting greens.

The development of the gardens in 1916 was provoked by the problems that CBM had establishing turf at NGLA - though I am not certain how much influence he had over getting it all started, and especially by the lack of quality bent seed coming out of Germany - the principle supplier of the best creeping bent. The war created shortages that could not keep up with demand here, and the seed brokers overseas were diluting the supply with Red Top. So they decided to cultivate it vegatatively.

The first really great variety to come out of that was Washington. Another one was Metropolitan. If you ever see some patches of purple bentgrass on really old greens after a hard frost, those are probably Washington bent.

[Alan FitzGerald CGCS MG]

I don't think height of cut has anything to do with greens being more susceptible to it because they are mowed lower. The perfect disease trifecta is presence of pathogen, moisture and the correct environmental conditions. Height of cut is not included in that. Although one exception is with anthracnose. A grass plant could be innoculated with bacterial wilt, wet wilt or pythium if it were at 6". It's just the perfect storm with the disease triangle and if a certain grassplant is susceptible to whatever pathogen is lurking around.

Ian,

firstly a plant can't be innoculated with wet wilt....

Secondly you're correct that height of cut is not specifically spelled out as part of the disease triangle, but isn't it an envirnomantal factor? and you admit yourself it is a factor in anthracnose however it is a factor in all diseases; Maybe hoc is not a direct cause but a plant at 6" (to use your example) is going to be way more capable of fighting/warding off a disease than one at .1" or less.

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