best artificial light system vs sunlight

[vyltan]

posted in artificial light forums, but no clear answer (same title). Is there an artificial light system equivalent to sunlight to obtain flowers as big as grown in greenhouses?

[mayres]

Yes, you can use artificial lights to simulate the sun's energy for growing big orchids/flowers. A number of factors will go into determining what kind of lights you will need - the type of orchid(s) and the scale of your project - one orchid up to thousands......
What do you have in mind?

[kinknstein]

Whether growing under lights or using sunlight, should make no difference to bloom size as far as I have experienced. It is all in the quantity and quality of the light being provided to the plant. With that being said, as an example I have a Blc Chunyeah #17, when I purchased it it had a 5" wide bloom grown in a greenhouse, I rebloomed it under HO T5 lights, mix of 3500k and 6500k bulbs (close approximation of sunlight) and the bloom was identical in size.
Maybe some other members can chime in with thier opinions as I am curious what others may have experienced.

[vyltan]

Well now we know a mix of T5 give similar catt flowers than sunlight. I grow approximately 40 phals in a 8' x 4' space with a 440w HPS bulb 'fortified' in blue light (hortilux) with intensitiy from 1300 foot-candles to 800 foot-candles depending on placement. But flowers are 10% to 20% smaller than when bought initially (large euphalaenopsis). I use MSU fertilizer 1/8 strenght twice a week with monthly flushing and use demineralized water. Good root systems, lots of stems, but begetative growth seems a little slow. 12hrs exposure year round (cycling not necessary to initiate bloom with that setup)

[kinknstein]

I haven't ever measured any of my phal blooms when I purchased them ( I have about 40 as well) but they too seem to produce blooms quite close in size to the original blooming. With regards to the vegetative growth being slow though, have you ever considered upping the hours in the summertime? I keep my lights on for 15 - 16 hours a day in the summer and cycling back to 12 - 13 hours a day in the winter. I get quite good vegetative growth with at least two leaves per season sometimes more depending upon which hybrid, not to mention a ton of root growth.

[vyltan]

and may I ask what is your light system?

[kinknstein]

I actually have both HID (Metal Halide 400W) and HO T5 systems. I grow my phals under the Metal Halide. I grow all my catts, oncids, paphs, phrags, prosthecheas, dendro's, and other asst chids under the T5's.

[Ray]

Originally Posted by vyltan

Well now we know a mix of T5 give similar catt flowers than sunlight. I grow approximately 40 phals in a 8' x 4' space with a 440w HPS bulb 'fortified' in blue light (hortilux) with intensitiy from 1300 foot-candles to 800 foot-candles depending on placement. But flowers are 10% to 20% smaller than when bought initially (large euphalaenopsis). I use MSU fertilizer 1/8 strenght twice a week with monthly flushing and use demineralized water. Good root systems, lots of stems, but begetative growth seems a little slow. 12hrs exposure year round (cycling not necessary to initiate bloom with that setup)

I don't think your issue is light - you are starving your plants.

While I believe your feeding frequency is probably adequate, the MSU fertilizer developer recommends a concentration of 125 ppm N. For the 13%N pure water formula, that's about 3/4 tsp/gal or 1 ml/liter. If you're doing 1/8 of that, you're only feeding 15-16 ppm N.

Also, phals do not respond to day length for spike initiation, they spike in response to a couple of weeks of reduced growth temperature.

[vyltan]

Ray, your input is GREATLY appreciated...I think I stayed with my old reflex about standard nutrients for general vegetative use, where it's stated to use it 1/4 strength every 2 weeks or 1/8 weekly for orchids. Thxs a lot for putting me straight!!