Florida Lethal Bronzing Status in 2022.

[BlueMarlin226]

Anyone with knowledge about the subject able to provide a current status update and outlook for this terrible disease? Most of the articles I find are from 2019/2020, and don’t provide much useful info. I used to live in Lakeland and didn’t notice it until 2020, and in the past two years it seems to have gotten so much worse in the I-4 corridor. Apparently it’s been in the state since 2006, so why has it seemingly spread so much in the past few years? Is it likely to get much worse, or is there any reason to be optimistic? Thankfully it doesn’t seem to be too bad on the East Coast at this time, having lived in and near Jacksonville for the past year and traveling around a good bit from here to the Keys.

[Collectorpalms]

2 hours ago, BlueMarlin226 said:

Anyone with knowledge about the subject able to provide a current status update and outlook for this terrible disease? Most of the articles I find are from 2019/2020, and don’t provide much useful info. I used to live in Lakeland and didn’t notice it until 2020, and in the past two years it seems to have gotten so much worse in the I-4 corridor. Apparently it’s been in the state since 2006, so why has it seemingly spread so much in the past few years? Is it likely to get much worse, or is there any reason to be optimistic? Thankfully it doesn’t seem to be too bad on the East Coast at this time, having lived in and near Jacksonville for the past year and traveling around a good bit from here to the Keys.

While not too scientific, in google maps I go into palmy neighborhoods and look over the years. You can find interesting things. I usually find the established Phoenix palms, and follow them. One by one in neighborhoods you can see them decline and/or disappear.  Yards or streets with several you can see them in different states of decline.

I love Canaries, but they seem to get the most diseases of any palms.

Edited June 22, 2022 by Collectorpalms

[Jerry@TreeZoo]

I know on FDOT landscape contracts, some landscape companies refuse to plant Phoenix species specified and ask for species change.

[Bill H2DB]

Here is the first hit on a quick search .

https://gardeningsolutions.ifas.ufl.edu/care/pests-and-diseases/diseases/lethal-bronzing-disease.html

   It's just been a few years since a similar event virtually wiped out our great Bay Trees .

 

[BlueMarlin226]

8 hours ago, Collectorpalms said:

While not too scientific, in google maps I go into palmy neighborhoods and look over the years. You can find interesting things. I usually find the established Phoenix palms, and follow them. One by one in neighborhoods you can see them decline and/or disappear.  Yards or streets with several you can see them in different states of decline.

I love Canaries, but they seem to get the most diseases of any palms.

I love Canaries, too.

What concerns me even more is the effect on Sabal Palms. While Canaries are nice to look at, they’re pretty much a luxury item, being regal looking ornamental palms. Seeing the rapid decline of native Sabals in Central Florida is truly alarming.

[ChristianStAug]

I have come to think  that my Canary Island Date Palm likely originally began its decline from lethal bronzing which led to gandoderma. In the past year, 3 more CIDP have died in close proximity to my house. I live in St. Augustine, FL. I think this terrible disease has arrived here.

[Merlyn]

It is definitely in my area, just down the road there is a clump of Sabals dying in the LB manner.  Across the street are more Sabals that seem ok so far.  A 15' trunk Sylvester quickly died in an LB manner last fall, but another next to it still looks fine.  About 2 miles away a new apartment complex planted 6 Sylvesters that all died from apparent LB...and were replaced with 6 more that are all half dead from apparent LB.  Another across 46 just died, but it hasn't spread to the other 6 or so at the entrance to the complex.  I am also watching 3 more that are rapidly dying, one just lost the final green spear last week.

[BlueMarlin226]

On 6/23/2022 at 6:06 PM, ChristianStAug said:

I have come to think  that my Canary Island Date Palm likely originally began its decline from lethal bronzing which led to gandoderma. In the past year, 3 more CIDP have died in close proximity to my house. I live in St. Augustine, FL. I think this terrible disease has arrived here.

I sure hope it’s not the beginning of a terrible trend. I know fusarium is an issue in the area, and have seen CIDPs and Washingtonias dying, but for the most part they’ve been healthy in my neck of St. Johns County. I read that LB has been reported in the area for years, but it doesn’t seem to be wide spread thankfully. That said, I was in Gainesville today and was surprised at how bad it was there. Seeing it rampant so far north is very concerning, to say the least.

[Bigfish]

21 hours ago, BlueMarlin226 said:

I sure hope it’s not the beginning of a terrible trend. I know fusarium is an issue in the area, and have seen CIDPs and Washingtonias dying, but for the most part they’ve been healthy in my neck of St. Johns County. I read that LB has been reported in the area for years, but it doesn’t seem to be wide spread thankfully. That said, I was in Gainesville today and was surprised at how bad it was there. Seeing it rampant so far north is very concerning, to say the least.

There are parts of town where it looks pretty bad, and other parts where you don't notice it at all.  Sylvester Dates are pointless to plant anymore.  Seems like they are the first to go.  At the Quality Inn on Newberry Rd. and I-75, there are only 3-4 left out of at least a dozen that were planted years ago there.  The SE side of town seems hit the hardest.  I'm on the NW side, and it's not bad over here.  It's pretty easy to spot when you know what to look for too.  The disease seems to attack cultivated palmettos more readily than wild ones.  I don't think people are going to want to pay the biannual treatment of oxytetracycline to keep a palmetto alive in their landscape, let alone a Sylvester Date.  In hard-hit areas, I think it might be a good idea to look out for resistant palms and collect seeds from them. 

[BlueMarlin226]

4 hours ago, Bigfish said:

There are parts of town where it looks pretty bad, and other parts where you don't notice it at all.  Sylvester Dates are pointless to plant anymore.  Seems like they are the first to go.  At the Quality Inn on Newberry Rd. and I-75, there are only 3-4 left out of at least a dozen that were planted years ago there.  The SE side of town seems hit the hardest.  I'm on the NW side, and it's not bad over here.  It's pretty easy to spot when you know what to look for too.  The disease seems to attack cultivated palmettos more readily than wild ones.  I don't think people are going to want to pay the biannual treatment of oxytetracycline to keep a palmetto alive in their landscape, let alone a Sylvester Date.  In hard-hit areas, I think it might be a good idea to look out for resistant palms and collect seeds from them. 

Downtown was a complete bloodbath. Situation almost looked worse than in Lakeland. Seemed like every other street corner had a crispy yellow eyesore. Alachua was also noticeably affected, but definitely not quite as much as Gainesville. Drove in after visiting the springs in Gilchrist. Seemed to get progressively better up through Starke (Which is tough on the eyes regardless of the palms lol. Sorry to offend anyone from there.), and then pretty much disappeared in Jax.

Edited July 5, 2022 by BlueMarlin226

[kinzyjr]

4 minutes ago, BlueMarlin226 said:

Downtown was a complete bloodbath. Situation almost looked worse than in Lakeland. Seemed like every other street corner had a crispy yellow eyesore. Alachua was also noticeably affected, but definitely not quite as much as Gainesville. Seemed to get progressively better up through Starke (Which is tough on the eyes regardless of the palms lol. Sorry to offend anyone from there.), and then pretty much disappeared in Jax.

Yeah, we're even losing the very large date palms on South Florida Avenue now.  Trying to keep count of how many dead or dying Phoenix sylvestris there are on I-4 from Daytona to Tampa would be a tall task.

[BlueMarlin226]

1 minute ago, kinzyjr said:

Yeah, we're even losing the very large date palms on South Florida Avenue now.  Trying to keep count of how many dead or dying Phoenix sylvestris there are on I-4 from Daytona to Tampa would be a tall task.

That hurts my heart to hear. Really beautiful trees on that stretch of road. When I moved to Lakeland in 2017 I didn’t notice anything wrong at all. By the time I left in late 2020/early 2021 it was a complete disaster. It was definitely worst on the highways, but even seemed to decimate the natural palmetto scrub in and around the town. I never could foresee it getting so bad. For a bit of hope I looked at street view in Corpus Christi, TX, where it supposedly kicked off. Looks like there’s a still a metric ton of palms (including date palms), with none appearing to be declining. Hopefully we’re just going through a widespread rough patch, but it will eventually fizzle out like lethal yellowing.

[Merlyn]

Here is an example of one of the local Sylvestris dying.  I noticed these about 2 months ago, the center one was yellowing and browning (bronzing?  not really...) the lowest fronds fairly quickly.  So I took a couple of photos at the time, and every time I rode my bike nearby I'd take a new photo.  The center one is now dead, and the other two are showing more rapid loss of older fronds.  I spotted no other visible symptoms of Ganoderma, Fusarium (sp. Canariensis) or Thielaviopsis. 

[ChristianStAug]

On 7/3/2022 at 11:38 PM, BlueMarlin226 said:

I sure hope it’s not the beginning of a terrible trend. I know fusarium is an issue in the area, and have seen CIDPs and Washingtonias dying, but for the most part they’ve been healthy in my neck of St. Johns County. I read that LB has been reported in the area for years, but it doesn’t seem to be wide spread thankfully. That said, I was in Gainesville today and was surprised at how bad it was there. Seeing it rampant so far north is very concerning, to say the least.

It will be particularly sad making its way more north with these species some of the main contenders for landscaping in the northern part of the state.

[Bigfish]

5 hours ago, ChristianStAug said:

It will be particularly sad making its way more north with these species some of the main contenders for landscaping in the northern part of the state.

I have a friend in South Carolina that has (probably “had” by now) it in one of his palms.  I’ve also heard from a nurseryman in North Carolina who says that he’s seen it there as well.  Almost certainly it is being spread by people hauling Florida-grown palmettos into the Carolinas.

[BlueMarlin226]

On 7/5/2022 at 5:20 PM, ChristianStAug said:

It will be particularly sad making its way more north with these species some of the main contenders for landscaping in the northern part of the state.

Indeed.

Any loss of palm trees is a tragedy. CIDPs are such an important ornamental, and Sabals are in my opinion the keystone of the Florida landscape. I personally think Washingtonias are kinda ugly and remind me more of California than Florida, but I still don’t want them to go anywhere, either.

[BlueMarlin226]

On 7/5/2022 at 10:38 PM, Bigfish said:

I have a friend in South Carolina that has (probably “had” by now) it in one of his palms.  I’ve also heard from a nurseryman in North Carolina who says that he’s seen it there as well.  Almost certainly it is being spread by people hauling Florida-grown palmettos into the Carolinas.

I assume those are just one-offs? From what I understand the palm hoppers that spread it don’t go further north than Florida.

[Bigfish]

On 8/1/2022 at 10:07 PM, BlueMarlin226 said:

I assume those are just one-offs? From what I understand the palm hoppers that spread it don’t go further north than Florida.

I'm sure it's being spread in the Carolinas, since the insects are being transported there. 

[Merlyn]

I still have a hard time understanding the declaration that "this disease cannot be spread by infected pruning tools."  This is stated on the UFL fact page and several other locations for LB and LY,

• From the LB page: "The LB phytoplasma is limited to the phloem (sap) of the palm and cannot survive outside a plant or insect; therefore, it cannot be mechanically transmitted (e.g., by pruning tools or infected roots touching new roots)."
• From the LY page: "It is not known to survive outside either its plant or insect hosts."

This still seems like a logical fallacy called "proof by assertion."  Hitchen's Razor is plainly stated "what can be asserted without evidence can also be dismissed without evidence."  I mention this because I haven't been able to find any scientific study showing the assertion to be true.  Clearly plant phloem (sap) can end up on a pair of pruning loppers.  All you have to do is cut off a live frond and look at the blades.  To prove that it can or cannot be transmitted by a pruning lopper (or chainsaw, or hand saw, etc) you'd have to run a couple of scientific studies:

• Determine the cause of death of phytoplasma when taken from the plant tissue and exposed to the atmosphere.  Is it UV?  Desiccation? Oxidation? A combination?
• Does it matter if the phloem is directly exposed, or does the phytoplasma die if, for example, if trapped between the closed blades of a lopper?
• How long does it take for infected phloem to no longer have detectable levels of live infectious phytoplasma?  1 second?  30 seconds?  20 minutes?  Clearly researchers have taken samples and transported them to a lab for analysis, but it's not clear if they determined if the samples are infectious after transportation and testing.
• Experimentally take phloem from a infected palm and inject it into an uninfected palm, and determine how long it takes or if the new palm is infected.
• Experimentally cut off fronds from an infected palm and immediately cut off fronds from an uninfected palm, and determine if the new palm is infected.

As far as I can tell, none of these tests have been done.

The best collection of LY research I found is here: https://www.cabi.org/isc/datasheet/38647  There clearly is evidence that planthoppers are a transmission vector, with a study showing field experiments where they collected Haplaxiuscrudus from fields with lots of LY infections and then distributed them to uninfected palms in a different area.    Palms with planthoppers subsequently tested positive for LY, proving a causal relationship.  This 2015 paper asserts that "information is still missing on many aspects of some of these diseases, including insect vectors, phytoplasma-vector relationships, phytoplasma-host plant interactions, strain virulence, strain interference, host tolerance, host range, and impact of the infections on the growth and yield of affected plants."  https://www.jstor.org/stable/24579127  There's research showing that grafted plants can transmit phytoplasmas from root stock to graft and vice-versa.  But there's no research on transmission by pruning tools. 

Personally I'd treat any pruning tool as possibly infected, with no way of knowing if it has infected phloem on it, or how long it may or may not last exposed to air and sunlight.  I'd wipe down between palms like normal with rubbing alcohol, though obviously there's no way to know if rubbing alcohol or hydrogen peroxide actually kills a phytoplasma. 

[Keys6505]

Does anyone have any experience with oxytetracycline HCl as a preventative or is it snake oil?  Trying to help my dad out, he has/had 3 mature palms in his back yard (Villages FL) planted close enough together that the fronds touched Sylvestris/Queen/Sylvestris.  One Sylvestris got got by LB last year and it looks like the other just started showing symptoms.  I'd like to treat the queen before it bites the bullet too.