Flat and reddish phalaenopsis root tips under LEDs
 

Hi, all. I'm trying to grow some phals under LEDs. They're doing fairly well, but I'm not getting the really long, plump, pointy root tips I was hoping for. Instead, root tips start out very green, pointy, and long, but end up red/brown on top, and somewhat flat.

Roots that grow in the shade of a leave are perfectly green and perfectly shaped, but when they get into the light, they darken, shorten, and flatten out on top.

I've attached the following photos:

1. Close-up of root tips.
2. All the roots on one of my phals.
3. A new root on a mini phal. Notice that it's very green, but starting to shrivel and turn red/brown.

Is this an indication that they're getting too much light? Here is a breakdown of my growing conditions:

• 1,500 foot candles of light.
• Main lights are 6,500 Kelvin with some 2,700 K supplements.
• Lights are on according to the season (14 hours in the summer, closer to 8 in the winter).
• Between 50% and 70% humidity (depending on the season).
• Temps between 70 and 77 degrees.
• Medium is lava rock.

Any thoughts?

Thanks,
Christian

The roots from my phals are also coming purple under the lights. I'd say it is normal.

tips of aerial roots turning red on NOID phal

The morphology is an aspect of their growth, nothing more.

The reddish color is pigmentation due to the light intensity.

This red pigmentation is called anthocyanin. It is your plant's reaction to light radiation. It is equivalent to humans getting a sun tan.

It will fade when you lower the light intensity or decrease the hours under light. Some growers like the reddish coloration.

As Ray said, the red pigment comes from high light exposure.

Your plants are getting far more light than they need to grow and bloom well. If they were receiving sunlight they would probably have burned by now. This level of LED light won't harm them. I have been told Phals have much larger flowers, and more of them, in lower light compared to higher light.

They also look underwatered to me.

They were under-watered in the past, but the new leaves (not in the photos) are firm and plump.

Thanks,
Christian

Your roots are perfectly normal.