Astrophytum Seedling rust/mold?

[Panda91]

Hello,

Should i be concerned about these orange marks on my seedlings?

Could this be rust?

ive noticed it on quite a few seedlings from different batches of seeds in different pots so not sure if i should be worried.

I am also noticing a white fuzz on the surface in some of my pots.

I pre soaked the seeds in diluted hydrogen peroxide before sowing and sterilized the soil and pots etc.

Thank you

g9an7l83n0961.jpg (70.3 KiB) Viewed 1199 times

seedlings 1cc.png (237.79 KiB) Viewed 1199 times

seedlings 2cc.png (258.35 KiB) Viewed 1199 times

[Jangaudi]

The third picture clearly shows mold. It's important to get the molded seedlings out as soon as possible, and take out as many empty seedcaps as you can, as they cause the molding in the first place.

[MikeInOz]

You have two kinds (at least) of things going on here. The seedling has been attacked by some plant pathogen. Probably pythium or phytophthora. These can kill seedlings overnight. These organisms do not form mycelium. That is caused by different fungi. Most probably growing on the seed husks. It is usually harmless to living plants but not always.
Both issues can be easily avoided by using a well matured biologically active compost as part component of the mix.