Alan:

1. Stop fertilizing the tree. Completely. However, it's alright to mulch.
2. Prune only in late summer. That would ideally be sometime during the month of August in Alabama, although any time after mid-July would be O.K. If your tree is crowded with twigs and branches, make it a pretty heavy pruning. Try to open up the tree to light and air circulation. I don't know what your previous instructions on pruning were, but if they involved pruning during winter or anytime during the dormant season they are off the mark. Dormant pruning is a good way to grow trees, but not fruit.

Don Yellman, Great Falls, VA

Not all apple trees bear well in all areas of the country. Perhaps those five apple grafts were just wrong for your area. Were you able to keep all the grafts alive and growing? Do you know the names of the varieties that set fruit?
I bought a five in one cherry tree from Starks. Over a five to ten year period, one graft grew into the main tree, and the other four were left as small, single branches. Two graft branches died over the years. The tree bloomed, but none ever set fruit. I finally replaced it with a cherry tree that does set fruit here, and never regretted it. Most apples are much more adaptable to different climates than cherry trees, but it sounds like those five are just wrong for you. You might think about the "four trees in a box" intensive planting, if you want a variety of apples. That planting is a little easier to keep going than grafts, and you can pick your favorite varieties of apples, rather than Gurneys.

Here is a link that might be useful: Backyard Orchard Culture

I pruned the tree about 3 months ago so this year (for the first time) maybe I hit the right time. Thanks, I did not know that pruning while dormant would hurt the fruit production. In previous years, I have pruned the tree while dormant (Dec. or Jan.)I hope this year will make a difference although it was purely accidental.
Alabama is not a good apple growing state. The tree was one of those "experiments" one does just to see if it was possible. And, the 5 in 1 variety was chosen mostly for a conversation piece. But, it's still a beautiful tree and is shading my deck. The birds sure like it too. Actual apples would be a bonus.

Alan:

The timing of your last pruning might turn out to be a happy kind of accident. I am convinced beyond any doubt that my switch to summer pruning about 5 years ago has been responsible for turning the orchard from a light producer to a level that even using most of the apples for cidermaking leaves me with a large surplus. I now realize that several trees I took out because of their busy, bushy growth and low productivity could have been turned around by summer pruning. You should begin to see the difference next spring.

I forgot to ask whether your tree had many blossoms, but I assume it did not or you would have more apples. I also assumed that your 10-year tree is probably on the semi-dwarfing M-7 rootstock, and is about 12 feet tall with equivalent spread. That would be about right on M-7. There is nothing wrong with planting a multi-grafted tree, aside from the fact that 2 or 3 (or even one) variety can come to dominate the others, but you can control these differences to some extent by balancing the pruning. I guess at least all 5 of your varieties have survived. Alabama should be just fine for growing a wide range of apple varieties, if you can control early insects like the plum curculio. I bag my apples in ziplock sandwich bags after thinning to one per cluster to frustrate the insects and eliminate spraying with insecticides, although I also dormant spray with oil about 2 weeks before bud break.

As to your specific question about applying lime to your slightly acidic soil, it is almost never a bad idea to put down 5-10 pounds of pelletized or ground lime around an apple tree, since apples need calcium. Whether the trees can actually utilize the calcium from lime is another question, but I tend to believe they can to some extent. Every other year, I also apply boron in the form of ordinary 20-mule team borax around the apple trees, using a full box spread around 30 trees, which works out to a little less than one cup per tree spread out to the dripline. Do not overapply borax or it can become toxic in the soil, as it is highly alkaline, and do not apply it on a windy day or it will blow all over the place. I believe the boron helps blossom bud development and fruit set, but again, don't overdo it as boron is a trace element not a fertilizer.

Don Yellman, Great Falls, VA

We had an almost tornado here. It blew over a 20 year old apple tree. Half of a 50+ year old pear tree. Many limbs on other.

This year we got no apples and no pears. Quite a few chestnuts.

I believe the pear and apple production was totally caused by the wind. I've noticed in other years when we had high wind that production was way off.

Here in Britain I see lots of apple trees in fruit. Most people just leave them to their own business and they fruit by themselves. I sometimes pick a few apples on my way around, such as a branch covered in apples that protudes over the owner of the trees fence and over the pavement.