This indented area of this one pad on this Opuntia just appeared today. Is this a disease or a fungus or something to do with watering? Should I cut this off to prevent it from happening to the rest of the plant?
I wouldn't think so, but who knows. Would they be inside of the cactus? because it is not on the surface, but under it. Thanks for your input. :}
Hard to tell as the pic isn't fully in focus - is the damage surface material that has been eaten away from the outside, or interior material that has shrunken? If the latter, then it is diseased, and best remove that pad. Disinfect the pruners after use, just in case it is something infectious. Oh, and guessing that you probably don't need telling but just in case ;-) wear disposable gloves when handling so you don't get those glochids in your skin, they're nasty!
It is sunken interior material. Thanks for your insight on everything. It'll be quickly replaced, I'm certain, not too much to miss. As for the glochids, I have no idea why I have to, but anytime I have somebody over who is looking at the cacti, I have to warn them not to touch this cacti because of the glochids. ha. One time, I had pointed to this certain plant and told a fried not to touch it, and not more than a minute later, he had touched a cutting which was the same Opuntia plant. ha. I told him not to touch anything in the house so I wouldn't be stuck with the glochids later. Thank you very much for your insight. :}
Reminds me of a trip I did to Arizona . . . my local guide was telling me to be careful not to touch the Jumping Chollas, because the pads would stick, he also said that their really jumping was a myth. So then I asked him why he was the one with a pad stuck to his shoe, even though he'd not been within a metre of the plant . . . he went very silent ;-)
ha. We all get stuck by a cactus from time to time, especially those of us who have such high levels of cactus radiation surrounding us at all times.