Two plants in question

[HP22B]

Hi,

The first of which is a Loph seedling that developed this white "crust" on the top. Is this sunburn or something more serious? It developed from normal looking tissue to this in about a month.



The next is this columnar that seems to be growing some weird lump. I would normally think it's an offset however it isn't coming out of an areole but the center of a rib towards the base.


Thanks!

[jfabiao]

The photo of your Lophophora is not very clear, but it appears to be sunburn. Other options may be red spider mite damage, although it tends to be produce a more straw-coloured scab, or damage from something you may have applied to the plant (have you?).
The other looks like a Trichocereus bridgesii, and if it's the case it is probably producing roots - they do that occasionally. Don't know if other species of the genus do it, but I would guess so.

[adetheproducer]

The white crust looks like salt build up from hard water. You may want to re pot it as the soil looks covered too. A few of my lophs had similar white coverings when I bought them but it clear away with new growt I do only use rain water for my plants to prevent the salts depositing when the soil dries out.

[HP22B]

I ruled out salt build up because I have a nearly identical seedling right next to it with healthy color that receives the same water and soil and everything. They are currently in my propagator tank for the winter so it would be a bit odd that the light is intense enough to burn but it does look this way. They have not been sprayed with anything.

I thought the growth on the columnar cactus might be a root too but I wasn't sure if roots could come out of anything but areoles or inner tissue directly (like from a cutting).

I've attached another photo of the seedling, hopefully this one is a bit clearer.



The soil mix I have it in is 1:2:2 commercial soil mix:pumice:limestone mix

[adetheproducer]

Yeah that picture is better, no it does not look like salt. Might just be a particularly pruinose. I have one a similar sizes which is similar but not as extreme.

[jfabiao]

I ruled out salt build up because I have a nearly identical seedling right next to it with healthy color that receives the same water and soil and everything. They are currently in my propagator tank for the winter so it would be a bit odd that the light is intense enough to burn but it does look this way. They have not been sprayed with anything.

I still think it seems like sunburn or RSM damage, and it happened some time ago because the plant is already growing out of it (the dark green tissue between ribs and around the apex is new, unaffected growth). Do not think "now" for what has caused this, think of what you may have done a few weeks ago.

[BarryRice]

I agree with all that Jfabiao said, but would add it is probably sunburn. If it was RSM, you'd still probably have them unless you took special effort to kill them.