Effects of light quality (spectrum) on plants

[mrred]

do you have a graph with the 300-0 part?

 

[binaryfission]

so is it safe to say that once we max out absorption of the red and green wavelengths that only adding more blue will increase "growth."??

 

[knna]

so is it safe to say that once we max out absorption of the red and green wavelengths that only adding more blue will increase "growth."??

I think is not safe to state that. In fact, I disagree that statement.

Most simplified statements are false. This one sure have some sense behind it, but is too closed and definitive to be valid, and goes way beyond our knowledge of how spectrum affects plants.

It is true that blue photons saturates photosynthetic systems at higher light densities.

 

[big ballin 88]

I really enjoyed reading this, it was very informative. It also made me start thinking about supplementing light. As you said earlier that with higher concentrations of light, bulbs with blue tints do better.

I'm currently upgrading my supplemental lighting and instead of the usual of going with 3000k i'm thinking about 4100k-5300k for the extra blue with the same red. I will be at 75w/sq ft. which is why i'm thinking of trying this out. sorry for being off topic, this just interested me and i would like to test it.

These graphs are what made me start questioning which to use, since they all have around the same output in the red/orange/yellow spectrum.

 

[danishpassion]

ive never tried CMH myself and heard mostly good about them
they are hard to obtain in europe
a freind and fellow grower tried a phillips cmh and wasnt impressed
in growth they made the plant stretch like an hps would do
in flower they yielded less than a hps
he ditched his after that grow but others have better experience
myself
i dont know what to believe and since they are both pricey and hard to obtain where im at i think ill stick with mh and hps for now

 

[elaromo]

Thank You!

Thank You!

Kanna,

Thank you for taking the time to educate us on horticultural lighting and its effect on plants. How wonderful it is to have somebody with your level of education on this forum. I hope that we can help you in your quest to further your studies because it would benefit all of us greatly! Let us now how we may be of service. Thanks again!

--elaromo

 

[vicious bee]

I was reading British Hempire somewhere else and he said he experimented with all kinds of lights. One thing I remembered him saying was that the type or wavelength of UV light in reptile bulbs was the wrong wavelength. So UV may be helpful just not the reptile CFL type.

 

[mexcurandero420]

Anyone tried ever to use the Exo Terra day light in a small set up???

Keep on growing

 

[Bud buster]

I've been growing with a 400 hps and 6 23watt four are opposite the hps they are 6500k & 5000k but since I added the cfls the leaves and plants turn to the cfls they like the spectrum better despite being only a quarter of the power as you can see the leaves exactly in the middle turn to the 92 watts of cfls versus 400 watt hps why?