Fungus, rot, or nothing to worry about?

[Msannic]

Hello,

I was gifted this prickly pear recently and I can’t tell if it is suffering from rot, fungus, or something else that I am unfamiliar with. The pot it has been growing in busted open and was duct taped back together, so I plan to repot it into something larger, but I want to figure out what I’m dealing with first. Should I be treating with a fungicide? Removing the healthy looking pads and starting over? It looks like it might also be trying to flower, which is a good sign, right? I’ve seen plants like this that were massive and covered in a similar pattern, so I’m not sure if this is normal for this kind. Should I just repot and hope for the best? Please help!

[hegar]

Hello Msannig,

your plant does not look like it is in immediate danger. It is actively growing. The brownish lesions are primarily present on the older stem segments (cladodes). Some of them would probably just be called "corking", which is rather normal with cacti. I do see a few darker grey spots on some of the lesions. Those are most likely of fungal origin. However, that does not necessarily mean, that your cactus is suffering from a major fungal disease.
The fungus could also be just a saprophyte or a weak pathogen.
I would not do any major cutting yet, but observe, whether or not the discolored spots grow or multiply. If you want to, you can also already go ahead and apply a fungicide, just in case the fungus is a bad one. There are some systemic kinds available if I am not mistaken. If there is a change visible and the lesions grow or multiply, I would cut off one or two healthy pads and root them. Opuntia spp. generally are easy to root.

Harald

[Msannic]

Thank you so much! I treated it with a fungicide yesterday and then woke up to a beautiful flower this morning (picture below)! Could have been a coincidence in timing but I’m going to credit your excellent advice. Once it’s done blooming I will repot it and give it more space to grow!

[hegar]

Well, your comment made me smile! Of course, I had absolutely nothing to do with your Opuntia opening up a flower. That flower bud was there quite a while ago.
As most likely already stated by me, prickly pear cacti are generally some of the easiest to grow. I am constantly thinning out the few I still have left, because they are taking over the whole yard. I have failed though, keeping one Opuntia alive. That was a beaver tail prickly pear (Opuntia basilaris).
A cactus club member from Las Cruces, New Mexico had given me one pad. I tried to root it and was hoping for establishing a healthy plant. However, the pad started to dry up from one side. After about two growing seasons, there was not much of it left. Then the cactus put out a weak new pad, which subsequently was killed by an early frost. Now I have another O. basilaris in the ground and hope, that that one will actually grow.

Harald

[mikethecactusguy]

This was on a slow death for 8 months. I finally treated it last month with Bayer Al in One. 30 days later it has rewarded me with all this growth.

IMG_20200522_152053.jpg (117.13 KiB) Viewed 668 times

IMG_20200522_152045.jpg (123.5 KiB) Viewed 668 times