Epson salts and high light plants

[rbarata]

I'm trying tp give it full sun as possible now while it's still not strong enough to cause damages. It never bloomed so I want to see how it reacts now.

[WaterWitchin]

So I’d just watch the pigmentation, and start pulling back if it gets too extreme. I have a Catt that requires really high light to bloom. It’s inside under lights. When one of the leaves turned almost totally red, I backed it off. If that makes sense?

[rbarata]

Originally Posted by WaterWitchin

So I’d just watch the pigmentation, and start pulling back if it gets too extreme. I have a Catt that requires really high light to bloom. It’s inside under lights. When one of the leaves turned almost totally red, I backed it off. If that makes sense?

And did it bloomed?

[WaterWitchin]

Not yet. Not right time. Just moved a couple weeks ago. Late spring blooms.

---------- Post added at 06:04 PM ---------- Previous post was at 06:00 PM ----------

And just divided last summer. We’ll see. Long time with it, so I know it’s gotta get lots of light to bloom. We’ll see in a couple of months.

[Ray]

Originally Posted by rbarata

I don't think so...it has been in and out, depending on the temps. The major sunburn you see is an old one, not recent.

That was my interpretation as well - lower light and the plant needs more chlorophyll and the converse. Marschner's Mineral Nutrition of Higher Plants, a university textbook, indicated that its a change in light level that controls the amount of magnesium the chlorophyll molecule can contain, not the other way around, or the amount of chlorophyll.

[rbarata]

Originally Posted by Ray

That was my interpretation as well - lower light and the plant needs more chlorophyll and the converse. Marschner's Mineral Nutrition of Higher Plants, a university textbook, indicated that its a change in light level that controls the amount of magnesium the chlorophyll molecule can contain, not the other way around, or the amount of chlorophyll.

So, if I understood correctly, the more light available, the less chlorophyll needed. So the chlorophyll levels in the leaves goes down, giving them the light green tone (due to the absence of chlorophyll).
Am I correct?

[neophyte]

Each molecule of chlorophyll contains one atom of magnesium, no more and no less. When chlorophyll is exposed to harsh light (e.g. UV rays), it is destroyed. This loss of pigmentation leads to lighter tones or bleaching. The reason that some leaves turn red under high light is because the plant produces more accessory pigments (e.g. carotenoids, etc.) that function not in photosynthesis but in absorbing excess light and preventing the destruction of chlorophyll and DNA. In fact, under high light sometimes chlorophyll itself is converted to red pigments that function in photoprotection.

[Ray]

Originally Posted by neophyte

Each molecule of chlorophyll contains one atom of magnesium, no more and no less.

Right you are - I misread Marschner. (I really should wake up before posting.) What was stated that the amount (fraction) of magnesium bound to chlorophyll changed with light levels and magnesium availability. I thought he was talking about only chlorophyll, not the entire plant.

For a fixed supply, under low light, a greater percentage is in the chlorophyll. With high light, more of it is elsewhere in the plant.

[WaterWitchin]

Y’all have moved way past my arena of understanding. Here’s what I would say... kudos to y’all for playing nice in the sandbox.

[rbarata]

When chlorophyll is exposed to harsh light (e.g. UV rays), it is destroyed. This loss of pigmentation leads to lighter tones or bleaching.

So it means that there is a threshold point on which the max. required amount of usable chlorophyll, for a certain light level. Increasing light levels beyhond that point, chlorophyll starts to get destroyed.
Considering this, light green tones on leaves is not always a good sign.

So, the question that motivated this thread is: considering Mg is used by plants to produce chlorophyll, if we increase it in watering would it help plants to cope better with light levels beyhond that threshold point?

I believe Ray's sentence quoted bellow is saying what I'm thinking.

For a fixed supply, under low light, a greater percentage is in the chlorophyll. With high light, more of it is elsewhere in the plant.