Ugh, doesn't look good, does it? Do you know what kind it is? If you don't, a closer shot of some leaves and the bark would be really helpful.

How often and how long (in terms of minutes or hours) have you been watering it? Are the leaves turning yellow and falling off, or did they all of a sudden get crispy and brown, but stayed on the tree? Have you had any - or many - instances of high winds in that area? Does it look like there's anything out of the ordinary on the leaves or on the affected branches?

Sorry for all of the questions, but it's a little tough to tell anything without a bit more info.... I'm sure others might want even more!

Thanks for the quick reply. I'll include additional photos this evening. To answer your questions...

1. I've been giving it a decent watering once every 10-14 days or so, but I must admit there was a two month period right after I moved in that it received little water and who knows how long it had been since it was last watered while the house was vacant. Right now though, I leave the hose on low to medium flow for about 75 minutes.

2. I never noticed the leaves turn yellow. I just noticed them kind of dull/crispy and far less of them, but only limbs coming off one or two particular branches - primarily the lowest one in the photo coming off the left side of the tree.

3. There haven't been any cases of high wind since I've been here. Although it appears the middle of the tree last part of the canopy in the past - I would imagine because of wind.

4. I haven't noticed anything on the leaves or branches that would seem out of the ordinary or be blatantly representative of disease.

JdBAZ

I can't tell, either, what kind of tree it is so maybe a closeup of foliage would help. However, it appears that someone topped the tree, i.e., cut off the trunk at the top. Looking at your photo, I don't see a main trunk past the point where the branches Y out. Topping is a nasty practice, usually done by nurseries who are more than willing to sell you a tree completely wrong for your yard by assuring you that its size can be managed by topping. Not. The tree usually develops 'issues', doesn't grow true and the wound at the topknot can let in pests and disease.

Here is a link that might be useful: Topping trees - a BAD practice

Sorry about the Sad Tree. No fun. :(

The shape of the trunk and the growth habit make me think it's a "Chinese elm" tree (sometimes called "evergreen elm" though I can't understand why as they drop their leaves in winter).

If the leaves turned brown and stuck to the tree, I'd be worried it has Texas Root Rot. Although like you mentioned, if it went a long period without water it could be a delayed reaction to that. Your current watering sounds pretty good to me, although slower/longer wouldn't hurt. Here's a quick little article on Chinese elms and Texas root rot.

I'm sure others will chime in too, but it sure looks like a Chinese elm struggling with root rot to me. If you keep up your current watering regime and it doesn't get better, I'd rip it out in autumn and replace it with a rot resistant tree.

Super good luck and do keep us posted.
Take care,
Grant

Here is a link that might be useful: Chinese Elm and Texas Root Rot in Arizona

I thought it looked like a Chinese Elm, too - but I was looking for fireblight - isn't that the one where the leaves just turn brown and crispy overnight? - but it didn't look like the CEs were susceptible to that. Then there's fusarium wilt.... I still need to refresh myself on all of this stuff.

But I concur with Grant, & even if you are able to arrest the problem, you're going to have a tough time getting the crown to ever round out (if that's important to you) so replacement is probably in your future. And assuming that it's a problem in the soil (likely) you'll have to find a tree that isn't susceptible, so it's important to figure out what exactly is wrong. Unfortunately, that seems to be the best cure for some of these diseases.

Ulmus parvifolia for sure. Texas root rot hits hard and fast, might or might not be the problem. Pay attention to continued decline. Check for borer holes on that sad branch. Watering should be longer than 75 min on that tree in my opinion. Be sure to water out to the drip line and to a depth of at least 3ft.

See if you can get a branch of the sick area, strip the bark below the cambium and take a picture of that.

I think a 2 week period of neglect would show througout the whole tree and not a localized limb.

I have noticed this limb on other tree's in the valley.

From what I'm reading, it almost certainly is Texas root rot - of course, the only sure way to find out is to get an arborist who really knows their stuff out to confirm it, or have someone test the roots of the tree as you bring it down.

There is a general .pdf with specifics about TRR (see link below,) and there are good suggestions about what is less susceptible to the condition:

' Fruit and nut trees such as wine grapes,
figs, apples, loquat, peaches and apricots are extremely susceptible;
landscape trees such as ash, elms, bottle tree, silk oak, pepper tree and
African sumac are considered very susceptible. Many shrubs including
pomegranate, xylosma, cassia, Mexican bird of paradise, oleander,
and roses also are very susceptible. Citrus, eucalyptus, live
oak and pine are considered more tolerant, but Texas root rot has been
confirmed on all of these trees. Others, including evergreens such as
Arizona and Italian cypress, mesquites, palo verde, Atriplex species,
hackberry, jojoba, and cacti are very tolerant.

All monocots, such as palms, yuccas, agaves and grasses are
immune and are good choices to plant anywhere that Texas root rot has
been observed.'
-Mary Olsen, Ph.D., Plant Pathology Extension Specialist, Department of Plant Sciences, University of Arizona

Here is a link that might be useful: Article on TRR

We were all so concerned about your tree, we'd like to know what's happened - or happening. Have you come to any conclusion and/or a solution?

Did it happy recently after the rains. I've heard that happens a lot to some plants/trees because a lot of salt accumulates over the years from poor watering practices by not watering deep and infrequently. Then, when there is a rain, the plant takes up a lot of salt and dies.

I'm thinking root girdling. The roots on the dying side are slowly strangling the tree.