Robin,

I've never managed a dwarf peach tree, but as no one else has ventured a comment, I'll offer some. In order of importance:

1. Have you done any fruit thinnning on this tree? I assume dwarfs still require the same amount of leaves to produce a fruit (around 30-35). It's the leaves that really feed the fruits. Too few leaves per fruit = small fruit with less sugar.

2. Adequate water during the fruit swell stage will produce bigger fruit.

3. Lastly, if the soil is extremely poor, a small amount of high nitrogen fertilizer, early in the season may improve fruit size.

As to your fruit not ripening, I've no clue. It may be they are infested with insect larva and drop before getting the opportunity to ripen.

In regard to a bum tree. It is possible you have a peach rootstock growing instead of a dessert quality peach tree. Some rootstocks will produce very small peaches. If this is the case, no measure of cultural practices will give you big peaches. Probably the best advice I can give you is to follow the above advice, and if you don't see any response, try different peach tree.

Genetic dwarfs are not reliable producers and the variety may not be matched for your area. Information needed, like where you are, what is the variety, is it a genetic dwarf as (opposed to a dwarfing rootstock which aren't often used for peaches), where was the tree purchased, etc.

Thin out your fruit, remove a few leafs directly around the peaches might help to ripen them. Check for small holes with clear goo coming out of them. This is OFM. There are sprays you can use. I was using Bonide Orchard spray So far I had a few peaches with bugs on them but it is a small percentage of the whole lot of them. I have also been picking the ones that look like the bugs are getting to them and cleaning the dropped leafs too. If anyone here has any suggestions or notices I am doing something wrong please let me know too!

Bonide link

I have a dwarf peach. This is its third year. It made a couple peaches last year. They never got big. My neighbor said it was because they needed sprayed, which he came over and did this year. Honestly, I don't know what he sprayed it with because I wasn't here when he did it. Anyway, has about twenty peaches. We'll see. Good luck!