Irradiated and Grafted
I have recently bought a cactus plant from market. Its a grafted cactus. You may see the attached photos. Could you please tell me what type of cactus is it? Secondly, the spikes/spines of the top yellow part is getting dark brown. Is it normal? I have just noticed a big brown spot on the lower part of the cactus. Could you please tell me if my cactus is ok or suffering from any disease? What should i do in this regard? Can i repot it with new potting soil in a bigger pot?
What you have is probably an irradiated echinopsis without chlorophyll grafted onto a hylocereus base to provide nutrients. These generally are not long-lived. There’s not much you can do, but if you want to try, repot the whole thing into fresh fast draining soil, and hope for the best. Don’t overwater.
[Have you noticed that when Hap answers questions, he goes into great detail, trying to help people save plants, while I tend to be more pessimistic telling people that it’s hopeless? I wonder what that’s all about?]