The combination of dwarf leaves and peeling bark at the base sounds like it could be the dreaded root rot. I suddenly lost a vigorous apricot to this. Usually you can see some form of the fungus growing where the bark came off.

Thanks nyRockFarmer for your response. I checked for fungus and I don't think there's any...I imagine it would be pretty obvious?
I called up the NOFA office today and they figure it's because the tree is exhausted from producing so many peaches last year. I'm going to wait and see what happens.

My guess would be winter cold injury. How cold did it get last winter? Could also be bacterial canker or poor soil drainage.

It's not from producing too much last year.

Is your picture recent? Your tree looks very stressed. I saw the picture of the trunk on another post. It looks like winter injury and/or canker.

I am in the Worcester County. Where are you in the Berkshire?

How wet is your soil? How are your other fruit trees? At this time, peaches in my area are full of leaves.

Yes, the picture is only a day old. I am in Petersham, not far at all from Worcester.

The soil isn't wet at all...in fact it was planted in rather sandy soil. There's another peach tree about 20 feet from it in the same soil and it seems fine (though no peaches). The rest of the fruit trees look great (we have 17 trees total).

Fruitnut - we had an incredible amount of snow this past winter, and most of the time the temperatures were below freezing. I looked for a bacterial canker, but I'm not sure what a canker looks like. The area around the trunk where the cracks are (in picture) looks permanently wet, but is this a sure sign of a canker?

I think you are in zone 5 b. I'm in 6 a but this past winter we were like 5 a.

What variety is this peach tree? Just wonder how cold hardy it is. This year there are so reports of fruit trees damaged or killed by the extremely cold weather. My peach fruit buds got killed anywhere from 20-80%. And I am in a warmer area than yours.

It's possible that the area of the trunk in the picture may got frozen and cracked. Once there is an open wound, any disease could move in.

It is said that keeping a tree healthy will allow that tree to heal from canker (if it's not too bad).

Hope it will recover.

It's most likely cold injury. Your tree looks better than a dozen others that have had the same question in the last month. But it's unlikely to recover fully. Better start looking for a replacement with some cold hardiness. Adams County Nursery has a very good chart in their catalog rating color, size, firmness, cold hardiness, and bacterial leaf spot resistance for peaches and nectarines.

This is a July Elberta. The leaves are still dropping off, unfortunately, and I'm wondering how a leafless peach tree is going to survive at all.
Nonetheless, it's a relief to know that this is probably a case of winter damage. I was afraid it might be a disease or pest. Thank you VERY much for your invaluable advice!
I went to the Adams County Nursery page but couldn't find the chart.
God bless you all for taking the time to help!