Spraying CAN-17 (Calcium Ammonium Nitrate) for the peaches

It's more for adding Nitrogen to the soil although it contains calcium carbonate.

CAN 17 fertilizer contains 8% calcium and 17% nitrogen. The nitrogen is one-third ammonic form and two-thirds nitrate form. This has two advantages:

• Fast acting nitrate form (nitrate-nitrogen) is available immediately to trees. 
• Long lasting ammonic form (ammonium-nitrogen) is held in reserve for later use.

The calcium in CAN 17 is water soluble and readily available to plants. Calcium assists in formation of new cells. If I am not mistaken, calcium also increases fruit quality (bright color, sweetness and shelf life).

Another cool use of CAN:

• Its dissolution in water is endothermic, so it's widely used in instant cold packs.

Not-so-cool use of CAN:

• It's used in explosive making. In fact, it is found in 80% of explosives in North America.