With fireblight, the tip growth is bent into the shape of a shepherd's crook and the affected leaves are black as if scorched. Might also see droplets of bacterial ooze.

See info at the link, below, about fireblight --
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7414.html

In any event, you would be wise to remove that dead part.

It's not like the fireblight I get here, which starts from the tips and goes downward into the wood with oozing as it approaches green wood and obvious canker. It looks as though something killed the cambium at the base of the tree- perhaps a fungal infection.

I would take the matter to a U.C. Davis pathologist before planting another tree. For about $30 you can have them scope it and report what can actually be seen. Use your county cooperative extension.

I didn't think you could grow yellow delicious in southern CA- supposed to need the chill hours of at least Z8. Maybe dying is a blessing.

Granny Smith, Fuji and Pink Lady would probably work (and produce apples far superior to what you are likely to buy) but there are two standard varieties whose names escape me that are especially bred for that climate- Oh yeah, one of them is Dorsett. When I lived there 30 years ago the only apple anyone one grew was called Beverly Hills.

from above..
>>Just got the tree last year, and it bore fruit this summer and they were delicious although small. <<

Scott

In googling diseases that affect apples, along with fb another possibility might be canker. Still haven't found enough info with good photos on that though. I cut off about 3-4 feet from the tree, and will see how it does before I get rid of it. Thanks all.