Peach Tree Copper Fungicidal & Pruning

Our peach tress have been afflicted by the so called "leaf curl" so this year we decided to apply some copper fungicide to help them out. This is what we did:

1. On Feb 4th, we mixed about 15 teaspoons of Liqui-Cop Copper Fungicidal Garden Spray into a bucket with 3 gallons of water.
2. On the same day, we loaded the mixture into our garden sprayer and applied it to the two small peach trees in our garden -- about 4 loads of the spray (6 quarts), being careful to cover the whole surface of the trees
3. On Feb 6th, we pruned the big peach tree -- we mostly cut big branches shooting at the sky, but we left the small branches for later pruning, once we get some more buds.
4. On the same day, we loaded the remaining Liqui-cop mixture into our garden sprayer and applied it the large peach tree that we had just pruned.
5. On Feb 15th, we mixed another 15 teaspoons of Liqui-Cop Copper Fungicidal Garden Spray into a bucket with 3 gallons of water and repeated the whole process for the three peach trees. By now, the two small trees have many flowers and leaves (all appearing to be healthy), but the large trees hardly has any leaves (or flowers).

Our application of Liqui-Cop followed the instructions in what regards the concentration, but we applied much less of the mixture that what was recommended. According to the instructions, we should have applied 3 gallons to a small tree or bush, 6 gallons to a medium tree, and 9 gallons to a large tree. Instead, we applied 3+3 gallons to all our trees (2 small trees and medium tree). However, since we used a garden spray, our application was very targeted and we felt that we really covered the whole surface of the trees.