Chlorotic Leaf Issue, Again!!

[Happypaphy7]

I did change, very early on with the light set up, the number of bulbs.
Some of the plants started to look funny very fast, in just ten days.
So I started to put one or two bulbs on off.
Some plants tall looked bad. I took them out of the light set up.

Now that the light bulbs are older, the light intensity has reduced noticeably.
The plants are overall greener than last year.

After about 20 months of growing some plants under light, I rather not have it this way, but it does help save space.
So, it will go on.

 

[Chicago Chad]

I always wonder if the light on for many hours at consistent level might stress these plants?

I think absolutely it will. I would use Eggshells culture as an example. He uses VERY low lighting at much shorter intervals than most advertise. I have started to follow that and from a reduction in light I have had far better growth without a shortage of spikes. In my very novice opinion I would say Paphs by in large do not need good quality of light, nor intensity, but rather volume and some variance.

 

[naoki]

If you have the photo of recovered plant, I'd like to see, hp7.

I don't think that it is due to the type of light. It is true that the circadian rhythms of plants are influenced by natural light vs constant light. But it has been shown that plants acclimate to the new environment after a couple weeks of constant light.

I have seen unexplainable chlorosis (less extreme than hp7's) a couple times. I tried a couple things, but I couldn't figure out the cause, and they are not repeatable. They usually go away.

Regulation of chloroplast development can be influenced by multiple factors. With hybrids, the mechanism could be not in-tune and screwed-up as mentioned earlier. In some plants (with certain mutations), temperature can cause chlorosis. In this other plant (arabidopsis), chilling induced chlorosis. But heating (warmer under the florescent light) could cause it, too, I guess. The light spectrum can influence chlorophyll a vs b ratio. But LED and fluorescent light are completely different in the spectra. So it is possible that yours is caused by the spectra of light. I would put it back to the same position and see if the same things happens again (I'm guessing that it won't be reproducible).

In some cases, I'm guessing that it could be due to the imbalance of factors needed for growth at that moment. In many cases, light is the limiting factor (so they invest more to leaves), but when you provide sufficient light, now the limiting factor could be nutrients. So the plant may show the nutrient deficiency like what myxodex mentioned. The plant would send signals to invest more to the roots, and after a while they reach to a new equilibrium (and the symptom goes away).

The appropriate amount of light is determined by many other environmental factors. For example, if the air humidity (and moisture in the soil) is low, plants can do better with the lower amount of light.

 

[Chicago Chad]

. So it is possible that yours is caused by the spectra of light. I would put it back to the same position and see if the same things happens again (I'm guessing that it won't be reproducible).

Indeed it was not reproducible in my case. It was one plant out of hundreds and it has since produced normal leaves. No change in culture other than temperatures decreasing with the seasons.

 

[Happypaphy7]

Naoki- the bleached Pink Sky returned from cream white to green gradually, but it started as soon as the plant was taken out of the artificial light.
Now it is looking completely normal.

This plant, Roth x Henry, is greening up on the cream white leaves. The new leaf that is just emerging is light green.

I don't ink why some plants get this way under the light, while most seem fine.
All the funny looking ones always return normal once they are moved to natural light.
I have no desire to put these two plants back to the light. However, others that I have placed back to the light, they immediately start to show bleaching. The shade of green is lighter with yellow cast.

The temperature is mild around 24-19C ( day - night), so no heat, no chilling.
The only suspect is the light, but only some plants.
Overall, as the light bulbs are now about 20 months old, I can tell the intensity is less. Plants are generally greener. I like it this way, but not sure when to change.
But whenever that would be, I think I will change one at a time to keep the leaves green like they are now.