Dear Falskers;

I wonder if any of you ran into this problem. It only seems to happen to paph or phrag flasks, I have not experienced it in any other genera, although I heard that stnahopeas will also do that occasionally.
A flask will be growing just fine for several months. Plants could as big as several cm in height, then all of a sudden, all the plants in the flask will turn yellow and die in a matter of couple of days. No evidence for contamination. It does not happen to all the flasks and seems to be random, but often enough to be a pain in the neck!
Any idea what is going on? How to avoid it?
Any help will be appreciated.

Best Regards,

Dear Falskers;

I wonder if any of you ran into this problem. It only seems to happen to paph or phrag flasks, I have not experienced it in any other genera, although I heard that stnahopeas will also do that occasionally.
A flask will be growing just fine for several months. Plants could as big as several cm in height, then all of a sudden, all the plants in the flask will turn yellow and die in a matter of couple of days. No evidence for contamination. It does not happen to all the flasks and seems to be random, but often enough to be a pain in the neck!
Any idea what is going on? How to avoid it?
Any help will be appreciated.

Best Regards,

Are your flasks vented? I've seen what you describe happen in unvented flasks. If they are vented, consider the possibility of mite infestation.

Haven't flasked in years, so what do I know?

Rob

It can happen sometimes when a flask contains a lot of plantlets, the media become saturated with metabolites, which eventually burns the roots.

The flaskes ARE vented, there is sub-micron filter, I doubt that any creature can get through! I very rarly get mold or bactrial contamination, so I am resonably sure that nothing except air gets in. How would mites get in? and from where? nothing else is grown in the cabinet except flasks.
Why does it happen to paphs and phrags only. I never experianced that for any other genenra.
No, the flasks are NOT crowded at all!

Adel

This can be genetic predisposition (unlikely) or that you needed to replate. As the plants live in the flask, they modify the pH by absorbing the nutrients. They may have been starved and burned themselves out with pH. Replate early and often.

That could be the case but:
1- I have flasks with much more plant mass that seem to continue to grow ok.
My experiance is that plant just stop growing and hold in place when they run out of nutrients.
2- I have other flasks from the same seed pod, same media patch ..... etc. that still thrive?
3- The ph could have been changed, I'll try to measure it on one of those falsks next time it happens.

Thanks for the input.

Adel