I have no experience with this specific disease. What I'd do is to spray the plant with diluted Physan 20 (or other fungicide) and keep an eye on it.

Thanks for getting back to my post Elliot. I will have a go at that. Fingers crossed I won't have to amputate!

If the environment is clean and air is flowing freely, it's not common to see fungus growing on the leaves of sans, unless there's physical damage or sunburn in the first place. So keep the leaves dry and make sure you don't overwater. Your media look like a peat/moss mix, which can cause root rot if you overwater. But that seems not of much concern for now since your sans look healthy and happy.

I'm not affiliated with Physan. According to its website: "Physan 20 is a broad range disinfectant, fungicide, virucide, and algaecide which effectively controls a wide variety of pathogens on hard surfaces and plants." It doesn't seem to burn leaves like bleach does, so I always spray some diluted Physan 20 if I suspect a fungal or viral infection. Cargo cult science? Maybe.

Use alcohol and a qtip to wipe the immediate area. Keep the leaves dry ( don't spray them with anything and protect from rain). Just keep a watch on it. Make sure you don't keep the soil too wet. It should be alright.

I'd remove the leaf completely, cut it at the soil line.

Also, what soil is that pls? Looks mossy & peaty & water retentive, not good for succulents or Sans. Stuff like that just invites rot & should be removed.

Karen brings up a good point- but I think the soil(less) is coir not peat in the picture, which drains better than peat.

Repotting would not hurt- if using a commercial blend mix in perlite to a ratio somewhere around 50%

Hi All,

Thanks for your help. Karen, In terms of removing the leaf, is that a knee-jerk reaction? Or will it simply halt the potential spread of the infection its as simple as that?

@Sans2014 I did put some anti-bac gel on the spots already, and whilst it dried them out. There have been more spots appearing on the inside of the leaf, so it hasn't helped much.

In terms of soil, @Sans2014 is right, its coir, so there's lots of drainage, and the pot sits on a bed of pebbles inside the outer pot, so its never sitting on a buildup of water at the bottom. I don't feel comfortable repotting currently, as the plant sits on my desk at work, so it would be quite a messy undertaking to perform in the office! But I will repot as soon as I can.

Thanks,

J

If the spots are spreading, I'd cut off the leaf too. Also you mentioned that it's in office, it would help the general health of the plant to let it get as much light and free flow air as possible.

Hi Karen,

I am new yes. Thanks for all of your advice. I will remove the pebble tray and resoil asap. I have removed the infected leaf now, so fingers crossed all is okay.

Many thanks for all of your help!

J