Cyphostemma betiforme leaf issue

[MikeDom]

The leaves on my Cyphostemma betiforme have started to develop brown patches which I haven't seen before. They seem to be mostly all over and I don't think it is the leaves dying back for winter. At least not before the fruit has matured. It looks suspiciously like a fungal infection to me but I may be wrong. Has anyone else come across this issue please? Many thanks for your help.

[Ivan]

The leaves on my Cyphostemma betiforme have started to develop brown patches which I haven't seen before...

Interestingly enough it looks very similar to this. viewtopic.php?f=1&t=164995&hilit=pimple
I'd be curious enough to find out as well.

[Tina]

Could it be from water droplets that have got cold, if it was mine I'd get the scissors to it and chop off any brown areas .

[MikeDom]

Hi Tina, I think you're on the right tracks. At this point I wish to swear very loudly.

My research shows it to be brown spot, a fungus that causes the leaves to turn brown and drop off. The leaves never get water droplets on them which is the way it is carried and the ventilation is very good, in fact this plant stands about a foot from the door.

Closer photographs of the C. betiforme look like this, compared with images on the internet of brown spot it is identical.

I had a scout around, nothing else infected apart from the C. quinatum. My large plant is heavily infected, the 43 seedlings shown below also are. More swearing.

It isn't easy to spot. If you look at the top surface of the leaf of C. quinatum it looks like this with only small blemishes, the vast majority of leaves that are infected show no signs on the surface and yet are infected heavily below.

The underneath looks like this (2 examples). How many people go around looking at their plants from underneath?

These plants are only infected in a small area at the moment. Surprisingly, C. pachypus and C. woodii are not affected [yet]. Nor are any other leafy plants.

My strategy is to spray today with this highly effective fungicide which I used to control fusarium in Aloe polyphylla. It needs to be absorbed through leaves so if I remove them there is no surface to absorb the fungicide into the plant.

Tomorrow I will strip the leaves, mainly those that are infected. The two sets of infected Cyphostemmas are more than 10 feet apart so a little bit confused how it spread, possibly me, possibly the friendly robin that comes into the greenhouse and pulls Lithops out of the soil, and more recently baby Ferocacti. Not happy.