Numerous hatchet cuts in avocado trunk bark for phosphoric acid application to control Phytophthora canker and collar rot, caused by <I>Phytophthora citricola.</I>.
Numerous hatchet cuts in avocado trunk bark for phosphoric acid application to control Phytophthora canker and collar rot, caused by Phytophthora citricola..
Credit: David Rosen