I don't use chemical pesticides, fungicides, or fertilizers unless they are USDA organic approved. Unfortunately that can make growing things challenging, especially when you live in an area plagued by endless diseases and pests. The technique I use for growing organic apples is called "bagging" (shout out to the good folks at gardenweb fruit forum where I first read about bagging, especially Don "Jellyman" Yellman).
In simple terms, this just means putting bags over your apples and pears (I'm told soft fruits like peaches require footies). The bag acts as a barrier preventing nearly all insect pests and some diseases from damaging your fruit.
The above picture shows the typical differences between bagged and unbagged organic apples. The one in the middle was not bagged while the others were. Bagging is probably the best current method of growing organic apples and pears in the Northeast where plum curculio (destructive beetle) thrives. The apple spends its entire growing life inside a zip lock bag. Yes, it looks ridiculous but it works!
So how exactly is this done, what kind of bags should you use, how much does it cost, and how much time does it take?
This is how I do it... first determine how many fruits you expect to have and how many you would like to bag and go buy the appropriate number of bags. You can do this during the winter months or wait until the last minute when you can actually see the blossoms and get a better idea of how many you'll need. It is best to prepare the bags ahead of time, trust me on this, it will take much longer if you prepare the bags "in the field". While you are relaxing, perhaps watching a little TV, you can prepare all of the bags, even better if you get the whole family involved. To get started I recommend doing them one at a time, take each zip lock sandwich bag, using sharp scissors (they need to be sharp) clip the bottom corners off, enough so that water can easily drain out the bottom of the bag when it is zipped shut at the top later. Cut these corners off diagonally, about a centimeter or 1/4 inch up from the corner (some people just cut SLITS at the corner instead of cutting anything OFF), then pull the zip lock open just a little bit (1-2 inches) in the middle (if you don't open them first, they are hard to open after you cut the top off), then take the scissors and cut off the heavy plastic pull tabs above the zip lock, you can do this by starting a cut and then just pulling the bag - it should come right off almost instantly in one quick tug. Cutting the tops off makes the bags lighter and prevents water from accumulating at the tops of the bags, both are important.
Now that you have your bags ready to go, wait until after blossom and petal fall. Put them over the newly forming apples as soon as they show anything a bag can hold to, they can be tiny and still hold the bags. It is important to get the apples bagged before any plum curculio damage.
I like to center my bags around each fruit and slide the zip lock shut as far as possible from both sides, right up against the stem as shown above.
Some people staple their bags, this seems like an unnecessary waste of time and resources to me, from my experience the zip locks will stay on even in severe winds and thunderstorms (perhaps some brands are better than others). A few of the bagged apples are going to fall off, but again from experience the apple was always still in the bag, in other words, the zip locks have never fallen off my fruit, so I do not staple the bags.
For a small scale home orchard, there is no question in my mind that bagging is the way to go. I've considered alternatives like the clay/barrier sprays such as Surround, but bagging seems easier compared to repeated sprayings, and bagging is also less expensive and more effective. I especially love the idea of "one and done" that comes with bagging, you do it once and that's it for the whole season. In most cases the home orchardist is going to hand thin their fruit anyway, so why not do the bagging at the same time, you won't really add much to your existing routine. I know of one person that has over 60 mature trees and he bags them all. Of course you could always only bag a few trees and expand from there in the future if you think its worthwhile. You could also just bag some of the fruit on any given tree, no one said you had to bag every single fruit. Another idea I had was that if you had so many trees that you could not handle it all yourself, and you give away a lot of the fruit anyway, you could offer an "adopt a fruit tree" program on craigslist for example, where someone local that was interested could bag some of your fruit for you in exchange for say half of the crop - this actually seems like a great idea to me, get other people to do all of the work but still benefit from getting at least half of the produce in the end, plus you will know that all of the fruit is being fully appreciated, you will have a chance to teach others, and make a few new friends. This could be just the sort of unique opportunity someone (or even some organization) in your community is looking for.
Here is one final pictorial showing the full sequence of before and after, this is how you thin and bag a cluster of apples:
Note: the apples only stand upright like that (pictures above) when they initially form, after they grow a little they will flop over and hang down, and the zip on the zip lock bag will be on top (with any rain water draining out of the clipped off corners of the bag that will then be at the bottom - imagine the above picture turned upside down). Also, as you can see in the picture, I start bagging as soon as there is anything to bag, the flower petals haven't even completely fallen off some of the apples! The tree may even still be partially in bloom.
I use the standard "sandwich" size bags, approximately six inches square. Larger apples can and will 'explode' the bag eventually, but its typically so close to harvest that it doesn't matter. Larger bags would generally be heavier and more expensive, with little extra benefit.
Note that after harvest, you can actually store the apples in their bags, this keeps humidity levels up slightly around the apple which reduces shriveling. I don't reuse my bags for a second season due to the deterioration that typically occurs after a full season out in the sun.
Give bagging a try and see what you think!
Some people take an additional step in preparing their bags, they snip the middle of the zip part so that when you put it on the apple stem it hugs it tighter. I think this is an interesting idea but the bag might be more likely to tear and then fall off if you compromise the strong zip parts. It is difficult to cut the zip without cutting past it, and this adds considerable time to preparing the bags. To me it just doesn't seem worth it but others think its better so I thought I would mention it.
One final concern is that some people have reported some black rot on apples inside the bags. I've seen this on some of mine as well, it is a fungal disease, but I'm not sure if it is made better or worse by bagging -- I've seen the same thing on unbagged apples. I think a very early (bloom/petal fall) pre-bagging spray of organic fungicide (Greencure) might help - obviously don't spray while the bees are active. Some think this may also be improved with increased ventilation (bigger cuts on the bottom of the bags) but I seriously doubt it.
I also want to note that bagging may save your fruit, but you may still have to take action to save the rest of the tree! You won't have to spray your fruit, but you may need/want to spray the leaves on an as needed or preventive basis. One organic option is the previously mentioned product, "Greencure" which can be used to control cedar apple rust, scab, powdery mildew, and many other common fruit tree diseases, and it's safe enough to eat (although I wouldn't recommend that :). I generally have a nice balance between pest and beneficial insects, with tons of lady bugs, but if aphids ever get out of control, a few drops of liquid dish soap per gallon of water sprayed directly on them is very effective. You should also learn to identify beneficials and more importantly, their EGGS so that you never harm them! Beneficials include lady bugs, green lacewings, parasitic wasps, etc. You can find pictures of any insect and its eggs by doing google image searches. Also learn to find pest insects and their eggs so you can eliminate them before they become a problem. You also need to be able to identify fire blight so you can cut it out of your tree as soon as you notice it.
Finally, don't use round up or common chemical weed killers on your lawn or around your trees, these products are extremely harmful to toads which otherwise will eat grubs and other pest insects that harm your trees. But the biggest mistake novices make is not keeping the space under their trees weed and grass free. Your tree will be much more susceptible to disease and other damage if it is not healthy, and the best way to keep it healthy, vigorous, and strong is by keeping it free of competition, and properly watered. There is once again a very simple organic solution to this problem: Just put down corrugated cardboard all around your trees (you can get it for free from any cardboard recycling bin, check small appliance stores, trash pick up areas, etc). You can cardboard RIGHT UP TO THE TRUNK, and you want to go as far out away from the trunk as the furthest branch tip (this is known as the drip line). After putting down the cardboard, you should dump a little compost on top so it looks nice. Boom, no more weeds. The trees love it, water passes though it, its free, the worms LOVE it, it keeps the roots of the tree from drying out, its all natural (the glue in most corrugated cardboard is nothing more than corn starch, even the dye is generally derived from soy, the paper is pine, it all breaks down over a two year period when you can redo it (this process even feeds the tree a bit). By the way, you can use the same exact method for simple weed free gardening too, just cut holes where you want to plant seeds and you won't have to pull a weed all season. I recommend at least two layers for a serious weed barrier.
You might be interested in this little "News 10" apple bagging video but please note that the method shown is NOT the way to go (he should cut the tops off of the bag and drop the unnecessary stapling as I describe above, you also want to prep those bags ahead of time instead of in the field if you have a lot of apples to bag).