These are just a few of my thoughts after reading all the suggestions and
Zootal's questions and replies.

Your links wouldn't come up for me so I'm just going on what I've read of
your descriptions and commentary.

All living things have a life span. You say your apple tree is now
approximately 100 years old. Because of a lifetime (the tree's, not
Zootal's) of insects, disease, neglect, ignorant maiming and now just plain
old age it's in death throws, why prolong the useless misery?

Putting netting over a 30 foot tree (that's about the height of a three
story building folks!) would be damned near impossible for the lone
homeowner to do unless they had a rocket launcher or helicopter. The mind
also boggles at just how large a piece of netting you'd need to get your
hands on to effectively cover that tree, never mind the cost and storage of
said netting. Then you need to get it back off the tree. Spraying that much
Diazanon, as it drifts over the neighborhood, your yard, garden, home, furry
and feathered animals, children, family and YOU is absolutely insane. WE
know better than that now!! Dormant oil sprays fall and spring should really
be the only thing you're spraying on your home fruit trees.

Get a nice, fresh, healthy, new tree. There is no law or moral mandate
chiseled in stone from The Mount that says you have to keep that tree. Why
anyone needs a 30-40 fruit in their home garden is beyond me. You aren't
getting descent apples, it's an ongoing PITA, you've put in hours of work
and worry with, so far, no return. Unless you really absolutely NEED the
shade what's the point? If you can't comfortably and safely pick the fruit
in your home garden without renting scaffolding or motorized equipment you
need to prune it lower. Use the wood for a fragrant winter fire, smoking or
grilling meat. Fruit wood is much sought after, if you don't want the wood
put an add on Craig's List.

Go to a GOOD local nursery and talk to them about what kind of apples you
want/like/desire, what they have that fills your desires, is disease
resistant and grows well in your area. Then ask about the care, feeding and
maintenance of your new tree and follow their advise. Learn about thining
apples to get the most productive crop. Learn how and why to prune. Seek the
advise of professionals, face to face visual contact is best. Hire a sherpa
to guide you to the nearest library. You'll find books with pictures, step
by step instructions and everything you need to guide you through an
ORGANIC, healthy relationship with your apple tree. If you find one book
with all the information you need and understand go buy it, keep it close,
read it often.

Pounding your head against a brick wall will only culminate in a bloody
head, no matter how sincere your warm & fuzzy, good intentions.

Val