Manufacturers still make wound treatments for fruit trees and landscape trees. The traditional types of tree wound treatments tend to be acrylic- or petroleum-based. An acrylic- or petroleum-based paste or paint is spread on the wounded area to seal off the tissue, prevent infections from forming and encourage the tree to create a callus over the area. You have the choice of using a commercial wound paste, or simply using black asphalt or white latex paint.
There are some newer, natural and environmentally friendly tree wound pastes on the market suitable for avocados and other types of fruit and landscape trees. These are made from substances like aloe vera gel, hydrogel and pectin. The natural nature of these new products can be compelling but, according to Chalker-Scott, there is no evidence to support that these products help wound healing.
Wounds and broken surfaces allow infections to enter a tree. In the past, many recommended applying a wound paste, after pruning or following damage, to prevent infections. Most professional horticulturalists no longer advocate applying wound dressings. If your avocado tree has a wound from pruning or damage, it might be best to let nature do what it does best.