Backyard Aquaponics
A place to discuss aquaponics

I'm sure theres a thread covering this here somewhere but I couldnt find it using search so here goes.

Do any of you use artificial light for growing and if so are you able to reduce the hours of light per day at a certain point in order to trick the plants into flowering or producing a crop much sooner than it would naturally?

there are some plants..i wont get specific but if you keep them under flourecent lighting for 18+ hrs a day they will essentially remain in a vegetative state and not flower once moved under metal halide of HPS lighting for 12 hrs a day the plant is tricked into flowering due to the fall like short light cycle.

has this been done with fruits/vegetables also?

Many plants are day specific Quad... most will trigger a flower/seed response when/if the daylight hours drop below 12 hours/day.... survival instinct

Similarly, spring flowering occurs for the same reason.... advent of > 12 hours daylight.... ain't nature wonderful.

Probably not the, or the only trigger mechanism in fruiting plants though...

So yep indoors I'm sure you could trigger other plants to flower... just like you do for the "other" plants

I know exactly which 'herbs' you are talking about! :smoking:

I'm sure this should work with vegetables as well, but the timing might be different for each type. I'd love to hear from someone who has tried this!

Isn't UV light used to encourage flowering fruiting... Or Infrared? Be interesting if you just had the invisible (or near invisible light for those who are going to correct me) on at night to promote flowering and aroma?

from what i've read

"The sun emits light energy that spans from the red to the blue end of the light spectrum. As far as plants are concerned, in spring-summer when plants start to grow (seedling and vegetative stages) there is more blue spectrum energy, that (along with long days) promotes plant growth.

In summer-fall when plants produce flowers there is more red spectrum energy, this (and shorter days) cause hormones in plants to increase flower and production. "

High pressure sodium light fixtures produce large amounts of red spectrum energy and are best for flowering.
'cool white' fluorescent bulbs produce light in the blue spectrum that promotes plant growth.

as far as LED's
pro's

SIMPLE
No ballasts, cooling fans or reflectors needed. LED lights use standard light bulb sockets.

LONG BULB LIFE
LED grow lights typically last 7 to 10 years before you need to consider replacing.

EFFICIENT
LEDs produce the blue and red wavelengths of light plants can best use in photosynthesis.

MINIMAL HEAT
LED grow lights are warm to touch and won't scorch young or tender plants as HID lighting can.

LOW ELECTRIC BILLS
For comparable plant growth, LEDs use only 20% to 30% of the electricity consumed by HID lighting.

VERSATILE
Blue LEDs can easily be added to enhance vegetative growth or red LEDs to promote the fruiting and flowering stage.

QUIET
LEDs are silent

Con;s
$$$$$$$$$$$$$$$$

HPS are best for flowering as the orange tinge (red spectrum) replicates the "harvest sun"............MH are better for the vegetation stage.

DO LED's produce the same wavelength required?

I don't know if there's scientific research to back it, but I'm a believer that stress can also provoke a flower/seed response in plants....

Like prolonged drough, fire (proven), heatwave, unseasonal frost, damage - for instance due to high wind.... just about anything that threatens a perception of death....

That's what I did when I wanted my guppies to breed faster, stress em out, they drop babies all over the joint. 50% mort rate on the mothers after, but hey who cares? I was only feeding them to my little barras anyhow.

as rupers has posted...................

some are triggered by less hrs
some are triggered by more hours
some are simply time related

and i'm sure that stress / weather patterns triggers yet others

does Peter Cundalls word count as scientific research? he says it works the plant gets stressed then "thinks" its dying so it produces flowers "thinking" its served its purpose before it carks it

I'd count it BK.... and seen as how he backs my claim I'd reckon that's scientific enough

..

I never got around to fully testing my LEDs out... just ran out of time I guess, plus the glow looked a bit suss, even though I was testing it on a tomato plant.

I came up with the ratio of 3 red LEDS to every blue, with a 5 x matrix. With added white LED, to get normal viewing colour, 3 UV leds and 3 IR LEDS. I can tell you at a metre away, using 10mm LED's the throw was only about 40cm diametre. Even using bulk LEDs from a previous project it probably cost $20-30.

I need to test 5 different ratios of blue and red LEDs, on 5 individual plants, in a controlled manner from small seedling. Figure out what ratio is best if at all. Then I need to get the best one and experiment further with IR/UV, see what that effect is. Finally, I need to determine if any combination can trigger flowering/seeding...

You can't beat the sun... plus it is free. I don't have the need to grow plants inside, nor do I need to hide the plants I grow from anybody. So I didn't bother looking into it further.

From everything I have read about HPS/MH lamps there is really no huge difference between the two except full growth on HPS will create leggy plants. HPS has more lumens per watt however.

As for LED's sure they work NASA uses them for their hydro experiments. I do a lot of reading on the other forums and they speak of when you wish to do flowering go to 12/12 and that is exactly what I plan to do. Currently I am running 15/9 due to some plants wanting 16 and some wanting 14. Run in the middle and it will be ok.

However running 15/9 my Chili Pepper plant is flowering like crazy so that may just be natural variance in plants... that and its huge.

I do not hide my plants either. I can promise you anytime I have opened the garage door all the neighbors know I am doing what I said I would

Apparently UV light damages the clear material in which the LED is housed, and they last only a fraction as long as standard LEDs. Perhaps a UV tube with LED arrays behind would be better...