pear tree leaf disease?

Hi, I have two pear trees growing in my backyard, one is doing much better
than the other. I am wondering if the black leaf tips on the weaker one (see attached) are
indicative of some kind of disease?
Thanks for any help,
-matt

Yes, that sort of yellow to black discoloration is not normal. I do not know specifically what is causing it. I would suggest you deep soak, flood the root zone in an attempt to leach out of the soil whatever might be doing this.
Follow up with a mild dose of a complete fertilizer, unless your soil tests and water tests show that the soil or water already supplies certain minerals enough for the plant.

General concept: If the plant is in soil that is too salty ( not just sodium chloride, but any of many different materials, often fertilizers) then the leaves will show it by turning black at the tips and edges. Other elements in excess like boron or certain other minerals needed in small amounts may be toxic in larger amounts. What you are seeing MIGHT be something like that. A soil test and a water test might help.

General concept: If there are herbicides causing problems the leaves might turn like this, or in other patterns, depending on the herbicide. Some herbicides tend to accumulate in the leaves so that one dose, perhaps months ago, can continue to make the leaves look worse and worse.

General concept: A lack of fertilizer, or any one element that the plants need will produce effects on the leaves that are pretty consistent from one plant to another. This does not look like a fertilizer deficiency to me.

When one plant is showing symptoms and a nearby plant, same species is not then the problem is not usually related to temperature, wind or similar problem, since both plants are exposed to essentially the same conditions.
It might be different watering, or perhaps there is something in the soil under or near one plant and not the other.

Try to think of any difference between the plants.
Check the irrigation. Are both plants getting a deep, thorough soaking as needed?

Thanks Diana, that is very helpful. The trees are both on drip irrigation, so they do get thoroughly soaked on a scheduled basis. They also both get fertilized on the same
schedule.

The problem tree is probably in a slightly rockier/more clay area of the yard, from what I remember digging the holes. So, I could see that the roots might be impacted and causing this, although I was hoping it was something else. This is it's second year. It started off pretty weak the first year, but had a growth spurt this year and was looking better, but now towards the end of the growing season, it started having this problem. So I will probably need to transplant to another part of the yard, unless something else could be causing this.

thanks,
-Matt

Part of the way to help clay soils is with organic matter.
Mulch well with almost any kind of compost, soil conditioner, bark and similar materials. As they break down they will improve the soil.

Drip irrigation can do a really good job of irrigating if you leave it on long enough.
I leave mine on all night long.