Q.Can Anyone Tell Me What Is Causing This At The Base Of One Of My Royal Palms
Can anyone tell me what is causing this at the base of one of my royal palms. The tree is very healthy and growing but the base looks bad. What should I do to cure it? Thank you in advance..

Certified GKH Gardening Expert
This is very good and important information! Herbicide damage is a very real possibility, since you are aware of its consistent use.
And yes, you can find your local extension in one of the links in previous conversation. It will give you a way to search out the closest to your area.

Certified GKH Gardening Expert
Sure. There are always chances of getting hit while trimming every time, or very over excessive use of weed killers. Typically, It would show symptoms right off, since it directly impacts living growths on the outside.
Possible damage from animals may be the case, or people pulling fronds off at the palm's young age. There are quite a few other possibilities!
It is simply the most common issue with palms, and I have seen many with this type of damage that turned out to be, but the best option for a definite answer would be your local extension service.
https://www.gardeningknowhow.com/extension-search
Other than that -which they can test for at the extension - technically, there is no definite way to know to confirm unless you see the fruiting bodies.

Certified GKH Gardening Expert
That appears to be a severe case of Ganoderma Butt Rot. Ganoderma species, though considered medicinal, are detrimental to many trees. This includes palms.
Whether you have seen the shelf mushrooms fruiting or not, this tree is on its way out, unfortunately. Replacement will be your only answer.
https://www.gardeningknowhow.com/ornamental/trees/palms-trees/ganoderma-in-palms.htm

you suggested I might contact our local extension service any suggestions who I would contact? Thank you for all you help thus far..

I was thinking I might build up soil to the point where the missing trunk starts and see if the root system might start to send out roots? I am pretty sure the reason the base looks like it does is the lawn guys always spray the area under the palms to kill the weeds. Could this have stopped the roots from trying to put down runers?

This has been the look for about 3 years and the palm is very healthy could it be something else?