What is it ans how it can be countered?

[Snowcat]

Hello, everyone.

Please take a look at this G. Ferox.



What is it in the lower part of the cactus? Some kind of fungi? It was free from it like a year ago. Now I see this "thing" consuming it. I cannot understand what is it. I cannot see any insects (in the soil also)... I've applied some fungicide on it and all others...

I've had another cactus (Echinopsis) that was comsumed by such change completely (I had to throw it away). Other ones standing near this one are completely free from this "thing"...

Maybe it is a natural process triggered by some conditions? Water for example? What can be done to prevent such change in future/to other cacti?

Thanks in advance!

[keith]

Maybe it is a natural process triggered by some conditions? ' Not sure what to do about it I can get it also on certain cactus that grow too slow and cork up.

[Snowcat]

Well, gymnocaliciums are not fast growers at all...

Yet I've had an Echinopsis, which grew quite fast and it was almost COMPLETELY consumed by such corking... That scared me...

[anttisepp]

Maybe this plant was very long time in the same pot same soil and "bonsaied"? Years ago I had the same problem with some of my indoor plants when repotting was deIayed for many years... I shouldn't exclude probable mite invasion or fungi infection. If this one isn't repotted yet I'd repot in larger pot and use as miticide as fungicide. Remember you promised to give them sun and fresh air in your balcony greenhouse next year.

[hegar]

Hello Snowcap,
I am kind of baffled by the image you posted. One thing I can say with a pretty high degree of confidence: This is not a pathogen produced condition.
It does look more like it could be the result of doing something wrong as far as cultivating the plant. One thing I would consider is perhaps the growth of some kind of alga, but that would be a longshot. It does look more like corking and may well be it.
I assume, that the discoloration is evenly spread around the stem of the plant and only present toward the base. The top does seem to be healthy.
How long did it take from when the discoloration first appeared until it moved up the stem to the point shown in the picture?

Harald

[Snowcat]

How long did it take from when the discoloration first appeared until it moved up the stem to the point shown in the picture?

It took quite long... I've acquired this cactus in this very pot (seller told me it could live without repotting for several years). Originally it had quite small amount of corking in very close to the soil. It took like a year and a half. For like fist 7-8 month of this time it lived on an north-eastern window (I've had no other options). Then It was moved to southern windows (I've changed the flat I live in). Can corking intensify because of lack of sunlight? This does not look logical, but...

The other thing that have changed for this plant is water. I use tap water, while originally this plant was grown in a greenhouse with a HUGE collection of cacti and there it was "fed" with rainwater when available and tap water was used only occasionally, when no rain water was available. Hardness of my tap water is medium, it is not soft but also not very hard (hard = high DH).

[hegar]

Hello Snowcat,
most likely what your plant is showing is the physiological condition called corking.
I do not know what causes this change on the cactus body. I do have some plants, which are pretty old and do not show any sign of it, while some do exhibit this condition. As long as the top of the plant continues to be green and growing, I shall have to accept it.
I just went out to my front yard and took two images of my large clump of Echinopsis eyriesii. Some of the stems do show corking quite well, while some neighboring ones do not to the same extent.
The reason must be some kind of environmental effect. Also, there seems to be genetics involved, which would explain, why some cactus genera do not show this condition, while others do.
You can take a look at the two images and will notice, that stems of the same age and size of exactly the same genetics (they are all derived from one initial stem) do appear different as far as corking is concerened.

Harald

Corking1.JPG (153.66 KiB) Viewed 1498 times

Corking2.JPG (129.56 KiB) Viewed 1498 times

[Snowcat]

Thanks, Harald, your images are very informative indeed! Maybe I should not worry THAT much about that...

[7george]

I have similar Gymno with the same amount but more brownish corking, still growing spines on the top.

IMG_0016g.JPG (98.59 KiB) Viewed 1449 times

So what is wrong with this one?

Have a Matucana being almost fully white corked wile grafted. It became green on the top after degrafting. "Miracles" happen. If no pests are seen better not to worry about.

Mat_5987.JPG (76.07 KiB) Viewed 1471 times

[Snowcat]

Thank you very much, everyone! Now I am much more reluctant about this then I was before! I was very afraid that it is some kind of fungi infection. Now I am sure it is just natural corking...