Dear Jakub, dear all,

many thanks for the info and I am sure that sub-optimally fertilised soil contributes to the stress. 
I am not convinced though that this is all. I would like to hear more about the GMI chamber that has exclusively fluorescent lamps installed but apparently houses plants without stress symptoms. What soil was used there?
As I mentioned to Jakub in an earlier email the plants in chamber #21 (relating to the picture) are still exposed to the light from the LEDs, though not directly. 
They are grown under fluorescent tubes, but are surrounded by LEDs.
Can I/we get some more systematic information on this please.

Many thanks and best regards,
Peter




On 28 Nov 2019, at 11:03, Jez,Jakub <jakub.jez@vbcf.ac.at> wrote:

Dear friends,
 
In the last weeks/months we have been investigating the plant stress issue, mainly focusing on the LED light spectrum.
Always comparing to the fluorescent tube standard.
Surprisingly, also the fluorescent tube setup shows same plant stress issues!
Which was not the case in the very beginning when we have tested and decided for the new type of soil.
 
See picture attached to this mail:
Phytotron: #21
Soil: Gramoflor2006; not sieved; with perlite
Light: Fluorescent tubes; LD
Watering: Flooding twice a week
Left side of the tray: WUXAL treated plants (once, after 1 month, 2ml/L)
Right side of the tray: untreated plants
 
Our new hypothesis focuses on the soil.
In particular, on the soil composition and the available nutrients.
From today’s point of view, it looks like the composition of the soil might have changed over the last months (without informing us); but this needs further investigation.
The automated watering system (flooding) also eventually contributes negatively to the problem by washing out nutrients; twice a week.
Also sieving might be suboptimal.
 
Red leaves are known to be a symptom for Phosphor/Phosphate deficiency.
 
We are in touch with the soil supplier and with APPN soil scientist from the BOKU to find a long-term solution.
 
As a quick fix
  • you can fertilize your plants with WUXAL fertilizer which is available in the Facility (once after ~1month; 2ml/L; watering from the top).
  • Use a long-term fertilizer (OSMOCOTE)
  • Use the old type of soil ED63
 
Please contact Anneliese in case of questions for the quick fix.
 
We will keep you posted on further steps and present you soon our final results and the long-term solution.
 
Looking forward to your valuable feedback on your quick-fix results.
 
Best wishes, yours PlantS Team
 
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Vienna BioCenter Core Facilities GmbH
Dr. Bohr-Gasse 3
1030 Vienna
Austria
www.vbcf.ac.at
 
Chair, Austrian Plant Phenotyping Network (APPN) and Support Group Member of ESFRI EMPHASIS project
 
Twitter: @VBCF_PlantS
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FFG PHENOPlant: Austrias 1st multi-sensor, high-throughput plant phenotyping infrastructure launching 2021!
 
 
 
 
 
 
 
 
 
 
 
 
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Max Perutz Labs
University of Vienna

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