Q.Oozing nectarine tree
It is mid-January here in Elgin, SE AZ, elevation 5,000. feet. We have been having freezing weather since early December. Our nectarine tree is 5 or 6 years old. Yesterday, while pruning, we noticed copious amounts of a clear jelly-like substance oozing from many places on the trunk and from a few branch crotches. Help!

This is a canker that is generally caused by environmental conditions or insects.
Here are articles that will help you pinpoint the cause.
https://www.gardeningknowhow.com/edible/fruits/nectarines/nectarine-fruit-oozing.htm
https://www.gardeningknowhow.com/edible/fruits/nectarines/growing-nectarine-fruit-trees.htm