Q.I was wondering what this was I just bought a new San Pedro cactus from a nursery and I’m worried it may be fungus or something
to worry about. In photo. Cactus stands about a foot and a half tall. And maybe a few inches in diameter.

drtreelove
Answered on October 14, 2018
Yes the spots appear to be fungal infections, possibly initiated with wounding. If it's a recent purchase maybe talk to the nursery. See the section on physical damage in this cactiguide:
https://cactiguide.com/cactipests/
https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/fungal-lesions-on-cactus.htm
Was this answer useful?
00