Madeline, Fertilizer brands tend to change by area but as long as it has the micro nutrients designed for fruit trees it will be fine. I just use a 10-10-10 but 8-8-8 is fine or 14-8-8 But again make sure it has the micro nutrients in it. What I do is look at the spread of the tree canopy and go with a pound of fertilizer per foot of canopy width. So if the canopy is 6 feet across you need 6 pounds of fertilizer which would be 12 cups. Some people use circumference of the tree to gauge the amount or age but my way is pretty simple and it does not need to be exact. You would fertilize 3 times a year...start like March then June then September roughly. But for your tree I would feed it about every 6 weeks until it gets all green and happy again. Spread the fertilizer starting 2 feet from the trunk (no closer) out to a foot beyond the dripline of the widest limbs as the dripline or just beyond is where most of the feeder roots are.

msk: It is possible, just possible, that your tree and your neighbor's as well, are suffering from a disease such as fireblight. Your description of leaves yellowing or browning does not really match fireblight, however, which usually turns the leaves black. I have some touches of fireblight on Asian pears this year for the first time, but it has not progressed much beyond a few smaller branches which I pruned off. Also have some touches of fireblight on my apple trees. But sometimes, when weather conditions are right, this disease can spread with a vengeance, and can kill a tree in one season. It might be worthwhile to Google "fireblight of pears" and find some illustrations to see if they are similar to what you are seeing on your tree. If not, you can eliminate this possibility, and good riddance. Aside from that, I am as puzzled as you about what could have caused this decline of your tree, and your neighbor's as well. Unless, as Bill suggests, you have had an awful lot of rainfall and are having some root rot due to poor drainage. Don Yellman, Great Falls, VA

I'm not an apple expert. I live too far south (Central Texas) for them to receive enough winter chilling. Most apple varieties do best in the northern third of the state where they can receive at least 800 hours of below 45º temperatures. All named varieties are clones (cuttings) grafted to hardier root stock intended for particular soil types. Buy trees from local nurseries rather than big box stores for better success in your soil. While the lichens on the older of the two trunks wouldn't be considered a problem for a large tree, I think they indicate this tree is struggling. The healthier looking sucker is also an indicator that the original tree wasn't doing well. Finally, most apples are self-sterile; they need another variety for pollination. I recommend you dig out this tree and plant two varieties somewhere else in your yard. This LINK is to a PDF for fruit tree varieties that do well in warmer and humid areas of Texas. HERE is a link to fruits recommended for North Central Texas.

Your 4th year may be the charm. I had several AP trees a few years ago but all were killed by "fire blight". It took about 4-5 years for some pears to be harvested (a couple of dozen, but the trees didn't last much longer for me). My reg pears suffered FB too but survived with many wounds/scares. footnote on the fire blight, for my trees it seemed to spread from bloom/clusters that didn't pollinate, usually from a late freeze here during bloom time. I wish I had learned this earlier to help save the trees, removing spent blossoms from the reg pears helps prevents the spread. Trimming off dying limbs didn't save the APs. Hope yours do well!