CactiGuide.com

Hello everyone! Would just like to ask for your help in identifying what might be the cause of the discoloration in my small barrel cactus (golden barrel i think?). Please help, so I can respond accordingly to it's needs.

As you can see on one side it has yellow spots and even have brown spots all around.

PS: I water this cactus every saturday since I live in a tropical country.

PS: it has white spots around it's body which I just wiped with cotton and rubbing alcohol. i removed as much aas I can but I can't get it all. I'm still not sure if that's the cause of the problem.

I am not able to give you a good diagnosis for your cactus. The top does look a bit discolored, but I cannot see enough to tell, if this might be a problem. The lowest tubercle on image 2 seems to have a lesion of some kind. Keep an eye on that spot. If it either increases in size within a few days or if additional lesions show up, it would be indicative of the presence of a pathogen.
I also cannot figure out, what the white spots were, which you removed with alcohol. They could have been just dried plant sap. They also could be mealybugs or armored scale insects. You can go into the section here named "Pests and Diseases" and take a look at the images. Perhaps you will find something that matches what you saw on your plant.

Harald

Thank you so much. Will do.