Fusarium strikes...AAAAaaaaaaAAAAaaaa!!!

[Merlyn]

On Saturday Fusarium claimed it's first victim in my yard, a $60 Queen I planted around June 2018 from HD.  I was out working on my agave bed and my wife said, "Hey, why is half of that frond dead?"  It took me all of about 30 seconds to recognize the Fusarium symptoms.  Red-brown stripe on one half of each rachis & petiole, half of the leaflets dead in a red-brown manner, and dying so fast that they didn't even have time to droop.  The last time I remember looking at that palm was about a month ago and I didn't notice anything unusual.  Here's the big view:

Nothing looked dramatically wrong until you stand underneath it and look at each individual frond.  Here's the first one I lopped off:

Here's a cross-section of the trunk about 1 foot above ground, with a pretty big brown section in a sorta triangular shape.

The cross-section at ground level looked basically the same.  I cut it over in the driveway with a reciprocating saw to avoid spreading fungus.  Below are cross-sections of the fronds I cut off, almost all had the one-sided death but a couple were dual-sided and one had a central dead spot in the rachis but still dead leaves on only one side.  Odd...  The two on the right were the first ones I lopped off, and the whole end had started turning brown.  So the one sided death wasn't too obvious.

I hadn't trimmed anything off of this one in at least 3 months, so it's unlikely that it was transferred to that palm from cutting tools.  I haven't seen Fusarium kill any other palms nearby, so I really don't know where this came from.  The only thing I can think of is that I got a delivery of 8 yards of topsoil/potting soil, and it could be contaminated with Fusarium.  That would really suck, since I paid a lot for it and I've already spread it all over the yard.  Or it could just be airborne fungus that happened to attack this particular Queen. 

So I carefully lopped off the fronds and bagged them up to prevent random spread.  I used the recip saw to cut the trunk into 5 pieces, bagged those and collected all the dust and random leaflets.  They'll be picked up tomorrow morning with the trash.  Hopefully this will keep it from easily spreading from palm to palm.

What other palms should I be particularly concerned about?  Right next to the queen I have a Dypsis Pembana, Caryota Mitis, Dypsis Lutescens, Beccariophoenix Alfredii, two Hyophorbes, a Butia, a big Chamaerops Humilis cluster and a Phoenix Roebellini triple.  20 yards or so away I have a Copernicia, a Zombia hybrid, a Corypha, Attalea Cohune, Cambeyronia and a Mule.  The closest queen is on the other side of the house, about 50 feet away.  Should I give the nearby palms, other queens and the mule a dose of Thiophanate-Methyl as a preventative?  Or is Fusarium simply not a risk for the other nearby species, and only a concern for Queens, Mules and Mexican fan?

[greysrigging]

Fusariaum will definitely take out Queen Palms. I lost a mature one about 3 years ago. The other one is still hanging in there. Ptychosperma species just give up the ghost and cark it in my yard.... luckily they are a weed here and the regeneration is greater than what the Fusariaum takes out. At least 75% of Golden Cane palms have succumbed city wide in Darwin.... 99% of mine died off.... the 1 or 2 remaining are are robust and strong.  Carpentaria very susceptible as are Roystonia. 
Older palms that might be at the end of their lifespan are at risk, as are plants subject to growing conditions stress ie water or climate zone pushing.
Not seen any Caryotas affected. nor any fan type palm.

[PalmatierMeg]

I lost all my queens, mules & a Washy to wilt in 2014/2015. It was relentless. My condolences to you.

[NOT A TA]

15 hours ago, Merlyn2220 said:

Or is Fusarium simply not a risk for the other nearby species, and only a concern for Queens, Mules and Mexican fan?

The info I've seen from UF/IFAS papers say the common hosts are primarily Syagrus romanzoffiana and Washingtonia robusta with rare occurrences in CIDP & Mules.

Sorry you lost a nice palm but thanks for the great documentation. I would not trim a Queen for fear of infection from air borne spores.  I finally took down a tall one I had a few years ago because it was in the front yard and allowing the old fronds to hang looked messy. It was getting too big anyway so no big deal.

Don't plant a suseptable palm where the infected one was as chlamydospores may be present in the soil. Hopefully you removed it soon enough but better not to chance it as the chlamydospores may survive in the soil for years.

[Merlyn]

5 hours ago, NOT A TA said:

The info I've seen from UF/IFAS papers say the common hosts are primarily Syagrus romanzoffiana and Washingtonia robusta with rare occurrences in CIDP & Mules.

Yep, I found the original testing done in 2006-2011 at UFL, and read through the whole results section.  It looks like they tested cultured samples of Fusarium Oxysporum v. Palmarum and v. Canariensis on a variety of common palms.  The two types of v. Palmarum that are super-lethal (~3 months to death) in Syagrus Romanzoffiana and Washingtonia Robusta/Filifera did not affect Chamaerops Humilis, Dypsis Lutescens, Phoenix Roebellini, Phoenix Sylvestris, Adonidia Merrillii, Ravenea Rivularis, or Livistona Chinensis.  So that's good news and agrees with everyone's observations.  Of course Mules are just as susceptible as the parent Syagrus, but they didn't give a time-to-death on those.  Apparently Butia is not affected at all.

The other Phoenix species (Sylvestris, Reclinata, Dactylifera and Canariensis) were killed or put into decline by the two types of v. Palmarum.  They did not, however, always show the typical one-sided-death of fronds.  Samples of Fusarium v. Canariensis apparently did not show the one-sided-death on any Phoenix, but still caused severe decline.  This makes me wonder if some of the apparent TPPD/LB deaths could be just from a "non-typical" Fusarium v. Canariensis infection?

Here's the research up to 2011, though it may continue beyond this file:

https://reeis.usda.gov/web/crisprojectpages/0207036-fungal-diseases-of-ornamental-palms-in-florida.html

[NOT A TA]

I believe you are correct that a lot of palm deaths are wrongly blamed on Lethal Bronzing due to it getting news publicity the past couple years.  AND, it's an easy out for landscape maintenance companies who may have spread Fusarium of both types or Thielaviopsis because they don't clean pruning equipment.

I should have mentioned in my earlier post (for those reading to learn) that while the specific Fusarium that kills Queens and Washingtonias  Fusarium oxysporum f. sp. Palmarum  doesn't infect most other palms there is a closely related Fusarium called Fusarium oxysporum f. sp. Canariensis that infects primarily CIDP Phoenix dactylifera and rarely other Phoenix species. The symptoms and outcome are the same for both types of Fusarium but if one type kills in an area there's no big need to worry about species that are susceptible to the other type of Fusarium if caught early. The Palmarum has rarely been found in CIDP although they have purposely infected CIDP with it. At least that's my understanding.

Also, only molecular testing can confirm which Fusarium infected a CIDP .

[NOT A TA]

@Merlyn2220 Did you happen to inspect for woodpecker damage? I've wondered if some of these diseases are also being spread by sapsuckers or other woodpeckers that wouldn't be affected by the diseases themselves. Been thinking more about them as a vector since I lost a Coconut to Thielaviopsis paradoxa after noticing woodpecker damage where the first symptoms showed up shortly thereafter.

[Merlyn]

51 minutes ago, NOT A TA said:

@Merlyn2220 Did you happen to inspect for woodpecker damage?

No, I didn't think to check.  We do have a woody-woodpecker around here, actually a big Pileated one.  It was all over my old water oaks, probably due to the dead limbs and bugs in them.  I don't know if I've seen it on any of the palms, but I can check my other queens and see if it's been popping holes in them or not.

[NOT A TA]

12 minutes ago, Merlyn2220 said:

We do have a woody-woodpecker around here,

My Queen had rows of holes in it from woodpeckers when I took it down. So at least some woodpeckers (here sometime during the year) like them. No disease when removed though. Might be a yellow bellied sapsucker vacationing in your area got your queen, they are snow birds.... (Pun intended).