The concept of the red / far-red system (phytochrome system)

[Opie Yutts]

Found it interesting, thought I'd share.

"A surplus of light like the strong UV radiation in high mountains causes drastically reduced elongation of the internodes, a decrease of the assimilating surface, often to a strongly enhanced production of anthocyanes and usually also to intensely coloured flowers."

"the growth of lettuce seedlings is not influenced by the subsequent exposure to light of the wave lengths lambda = 658 nm and lambda = 768 nm, while the exposure to both wave length at the same time increases growth."

So what can the phytochrome system do for me? Oh not much, just

Inhibition of the elongation of the hypocotyl
Inhibition of translocation from the cotyledons
Increase of the surface area of the cotyledons
Unfolding of the cotyledonsâ?? lamina
Development of hairs at the hypocotyl
Opening of the hypocotylâ??s hook
Development of the primary leaves
Development of mature leaf primordia
Increase in the negative geotropic reaction of the hypocotyl
Development of xylem elements
Differentiation of the stomata within the epidermis of the cotyledons
Development of super-etioplasts in the cotyledonsâ?? mesophyll
Changes in the intensity of the cell respiration
Synthesis of anthocyane in the cotyledons and the hypocotyl
Increase in the synthesis of carotenoids
Increase in the capacity of the chlorophyll synthesis
Increase in the RNA synthesis within cotyledons
Increase in the protein synthesis within cotyledons
Intensification of the storage fat breakdown
Intensification of the Storage protein breakdown
Increase in the synthesis of ethylene
Acceleration of the Shibata-shift within the cotyledons
Determination of the cotyledonsâ?? capacity to photophosphorylate
Modulation of the cotyledonsâ?? enzyme synthesis

More:
Botany online: Plant Responses - Light - Photomorphogenesis, Phytochrome

Opie Yutts Reviewed by Opie Yutts on 02-10-2008. The concept of the red / far-red system (phytochrome system) Found it interesting, thought I'd share. "A surplus of light like the strong UV radiation in high mountains causes drastically reduced elongation of the internodes, a decrease of the assimilating surface, often to a strongly enhanced production of anthocyanes and usually also to intensely coloured flowers." "the growth of lettuce seedlings is not influenced by the subsequent exposure to light of the wave lengths lambda = 658 nm and lambda = 768 nm, while the exposure to both wave length Rating: 5

[Zcomp]

Mind me if I sound simple but, Is this to backup HPS usage or something more serious?
It sounds to me as if these are just symptoms of good growth under HPS.

[SnSstealth]

thanks opie,

I see cotyledons on most of those listed, is this just for seedling growth or whole cycle. also i thought lettuce was a low light plant.

Doughboy

[SnSstealth]

Yo,

I got thru about 1/2 of that before my head started hurtin (sorry had to jab there). seemed like there comparisons were darkness to far-red not red to far red. IM NOT saying its not useful though.

there is something to the uv higher latitude thing...uhh Alaskan thunderfuck anyone?

Doughboy

[maspino1]

lol what's an alaskan thunderfuck?
doesn't this info just make you want to pull your hair out? you invest in a cost of 1 leg for LEDs and
you find out it's not really even enough

[SnSstealth]

lol its a strain grown in Alaska thats quite powerful

no not really

[SnSstealth]

seems you dont have to go far to find discrediting info

Plant Physiology Online
Some initial success in purifying phytochrome from etiolated oats (Avena sativa) was reported in 1964 (Siegelman and Firer 1964), and many workers subsequently used dark-grown oat seedlings for phytochrome extractions. As a result, much of the biochemical information on phytochrome is derived from studies on oat seedlings, although there is a considerable amount of data on phytochrome isolated from dark-grown rye (Secale spp.) and pea (Pisum sativum) seedlings as well.

so chemically altered mustard seed in a petri dish and dark light oats need far red light. and people bitch at us for claiming they grow tomatoes...lol. I'm not saying we couldn't use more lights but as far as "you invest in a cost of 1 leg for LEDs and
you find out it's not really even enough". it seems as if it's "enough" for veg anyway.

"to discover new methods of growing, the marijuana cultivator must experiment and through failure learn more" - Greg Green, the cannabis grow bible

Thanks again opie
Doughboy

[physicsnole]

Ya Opie there are alot of benefits by manipulating the Phytochrome FR and phytochrome R in plants. And I did read on a french grow site that a 2:1 blue:red is optimal for vegetation and at least a 2:1 red:blue is required for flowering. The reason is the flowering stage needs the red light for the phytochrome and other cells in the plant, while the red light is not needed for vegetation. The UV-B (310-315nm) has many positive effects that I think needs to be implemented in a LED growing situation, since with LED's we are only giving blue and red. UV-B wavelengths are not commercially available as LED wavevlengths YET, however I emailed a company who said they can produce any wavelength ALHA-ONE ELECTRONICS LTD. _LED. Also Opie, can you furtur your discussionon why green and other colors arer needed? I have found little on this subject so your imput would greatly be appreciated.

[Zcomp]

I was under the impression that my HPS gave great red spec. And my UV-B reptile bulb took care of Blue spec. Together I thought they were unstoppable. I relize that MH also offers UV-B but to me has poor LperW. And greater heat generation.
I also can't figure out what % a MH bulb emits in that spec.

[Opie Yutts]

Mind me if I sound simple but, Is this to backup HPS usage or something more serious?
It sounds to me as if these are just symptoms of good growth under HPS.

No Z, this is just some interesting info about how light outside the visible spectrum influences plant growth. At least it's interesting to me, and it darn well should be to anyone thinking about grow light design. We were talking about it in SnSstealth's LED thread, but I thought it warranted a thread by itself.