Canary Date Palm Fungal?

[jkell]

Any idea what type of fungus is this on my canary date? I just trimmed today and noticed all over. This palm is located in Southern California close to the ocean. Anything I can use to treat it ? The tree is about 40 ft tall so not easy to spray consistently.

[kinzyjr]

Looks like graphiola leaf spot.  Phoenix species (canariensis, dactylifera and theophrasti in particular) get this in more humid climates.  You don't typically see it in more Mediterranean climates, but your proximity to the coast must be elevating humidity levels to the point where it is an issue.  Here in Florida, it is almost unavoidable.

http://idtools.org/id/palms/symptoms/factsheet.php?name=Graphiola+Leaf+Spot

[jkell]

Thanks  you are right! Do you treat it or just let it be? 

[kinzyjr]

6 minutes ago, jkell said:

Thanks  you are right! Do you treat it or just let it be? 

I remember trying to treat one of my date palms as an experiment by spraying one frond on my smallest Phoenix dactylifera with a product that was supposed to stop the sporing process, but that frond browned up and died almost immediately.  At that point, I reserved myself to living with the cosmetic damage.  If anyone else has a suggestion for treatment, I welcome their suggestions as well.

[Fusca]

4 hours ago, jkell said:

Any idea what type of fungus is this on my canary date? I just trimmed today and noticed all over. This palm is located in Southern California close to the ocean. Anything I can use to treat it ? The tree is about 40 ft tall so not easy to spray consistently.

Graphiola usually just affects the older lower leaves and causes individual leaves to die off a bit sooner than they normally would.  I hate it but don't know of any effective treatment for it.  My Phoenix theophrasti has a bad case of it and I just noticed some on a Phoenix silvestris  quite a distance away.  Not really that noticeable from a distance but up close looks really bad as your pics show.  Take care removing infected fronds to limit spreading the spores.  Your pics shows them at various stages of maturity - the most mature being ones with the fiber-like "tails".

[kinzyjr]

The information on this thread I started about some new leaf spot that was primarily affecting Phoenix theophrastii may help.  @Merlyn2220 had suggested Banrot at the time.  It had slipped my memory that I wanted to try it.  I had a few theophrasti succumb to this weird leaf spot, and a few others that were either not touched or barely touched.  The remaining palms seem to have some level of immunity to this disease.  I guess it couldn't hurt to try Banrot on graphiola as well unless @Fusca has already tried it with no luck.

https://www.palmtalk.org/forum/index.php?/topic/60388-phoenix-theophrasti-leaf-spot-disease/

[Merlyn]

I dosed my Phoenix Canariensis with Banrot not too long after planting it in April 2018.  All the new fronds grew out with no spots, and I think there is still one "original frond" on there from when I purchased it.  Mine had more of the black spots instead of the raised bumps.  I've seen CIDP in local nurseries with just the raised bumps and no black lesions on the leaves.  So I'm not sure that the two diseases are the same, they may be independent or just opportunistic infections that just happened to show up at the same time.  I had good luck with Banrot on that palm and have continued to use it on others with good success against common fungal infections.

Banrot is definitely a soil-based systemic and should not be applied to the foliage.  As I found out by accident, you can kill a seedling overnight with a squirt bottle of Banrot if you forget to rinse it off the leaves.  I squirted a few potted seedlings and accidentally hit the leaves on a Dictyosperma Rubrum.  I got busy with other stuff and forgot to rinse it off the leaves...the next morning it was brown and dessicated.

[Kris]

Even our date palm had this problem,kept trimming those fronds often. And stopped watering that palm.Immediately from spring season when these palms start flushing new fronds,there was no such problem.

i.e stop watering the infected palm and feed fertz only during intermittent rains. you will see the difference.

But initially that palm needs a hair cut!

Love,

Kris.

[jkell]

Great thanks for all the advice!