Can someone tell me why my apple trees have not produced leaves yet?

Question:I did the scratch test and the treees are alive. They are now one year old and seemed to do very well prior to the winter.

Answers:
Not sure where you live but in my area (zone 7B) we had a frreze after some trees has started to come out of the winter slump. My fruit trees were just starting to leave and the freeze stopped it. Although I have "some" leaves, there are not near as many as usual. My trees are still alive but it doesn't look like I will have any fruit this year.