It looks like your tree has gummosis, which is oozing of sap caused by environmental stress, some type of injury or insects or a fungal infection (bacterial canker).  I cannot tell from your picture what is causing the gummosis.  If you see sawdust mixed in with the oozing sap, you may have some type of boring insect.  If you see signs of insect activity, you'll have to treat for the insects.  Since the gummosis is on the trunk, you can try to scrape away the diseased wood so the tree can heal.  Fungicides are usually ineffective on bacterial canker.   You can also consider contacting a certified arborist to see if they can determine the cause of the gummosis on your tree.  You can find a certified arborist in our area at Home | TreesAreGood.org,

Here is some information on gummosis.

Gummosis of Fruit Trees

Peach Diseases | Home & Garden Information Center

If you have additional questions, please contact us.