Medjool Trunks Snapping

[Susie's Garden]

We had 2 Medjool trunks fail in one area of town about 10 feet up off the ground during yesterday's storm.  We had another one fail at about the same height on the 23rd in another subdivision. Previous freeze damage? Insects? All came back negative for Texas Date Palm Decline. No odor of rot or other obvious signs or symptoms.

[Kim]

I wouldn't know much about this. In San Diego we are losing a lot of Phoenix canariensis to red palm weevil, but this looks different. Anyone?

[Matthew92]

I saw the exact same thing happen in Pensacola. Check this post I made about it. Pensacola Date Palm Disaster - FREEZE DAMAGE DATA - PalmTalk

[Merlyn]

On 1/1/2021 at 1:57 PM, Susie's Garden said:

We had 2 Medjool trunks fail in one area of town about 10 feet up off the ground during yesterday's storm.  We had another one fail at about the same height on the 23rd in another subdivision. Previous freeze damage? Insects? All came back negative for Texas Date Palm Decline. No odor of rot or other obvious signs or symptoms.

 

These three photos make me think Thielaviopsis, though I didn't see any of the "bleeding trunk" marks on the other pictures.  Thielaviopsis rots the soft fibers in between the hard, stringy ones, starting from the outside of the trunk inwards.  It is frequently carried from palm to palm by woodpeckers, supposedly.  One of the symptoms is soft dark brown material around the stringy fibers.  As the rot works it's way inward the trunk loses strength, and sudden crown collapse is common.  The cross-section of the trunk has an area around the bottom perimeter that looks brown and squishy, like it is rotted away.

If it's Thielavopsis there is no cure, but products like Banrot claim to work.  Here's more info about it:

https://idtools.org/id/palms/symptoms/factsheet.php?name=Thielaviopsis+Trunk+Rot

[NOT A TA]

Based on what I see in the OP pics I'd concur with @Merlyn on a probability of Thielaviopsis. I've seen similar wind events snap off Queens with it here which seem a bit more prone to be infected with it than other palms. The bleeding doesn't necessarily show up on all cases and some varieties rarely show the symptom. I had a nice Green Malayan Dwarf coconut I lost to it last year that was infected at a point where woodpecker had made holes. On the coconut there was bleeding observed.

While the disease can enter any fresh wounded tissue I believe the woodpeckers may be spreading it here. If they poke some holes in a palm and then return to others that they made holes in previously to collect bugs feeding in the holes which have the disease they can then move the disease to new trees. So it's not that random spores floating in the air find their way to a little woodpecker hole but that the birds are transporting the disease in the same way that uncleaned trimmers tools transfer diseases. In the case of the queens here, perhaps our local woodpeckers like the queens more than some other varieties so they are infected more often.

[96720]

In some strong storms in Phoenix we also loose some date palms but I never thought of it as something but microburst. This is very interesting I will have to look closer next time one breaks.