January 24, 2010 by gisette
Test 2: Tomato and Pepper
Built similar lightbox to Test 1: Greens.
Lights: first phase, same as Test 1: Greens. After the greens test is done, though, I intend to add bulbs to the tomato and pepper test. Possibly, the tomato or pepper test, depending on how they do.
2009-01-23: Presoaked a couple hours. Planted 3 seeds per pot (will thin to 1), a pepper pot and a tomato pot on each light side.
- carmen pepper
- jet star tomato - compact indeterminate, have grown before...unsuccessfully indoors
In fresh Miracle Gro potting mix.
I've grown carmen peppers indoors before - grew to transplant size in the spillover light between 2 AG Minis, then grew to first harvest by a chilly winter west-facing window with <3 hours / day of sun. I'm pretty confident the peppers are fine in this rig. The tomato... I've grown before indoors, unsuccessfully. But it should be OK with just the one light... probably.
Hypothesis: My best guess :
- There is enough light (barely) to grow these to transplant size (4-6 week size).
- There will be < 10% difference between lights in transplant size.
Anyone else want to bet? 
Germination:
day 5: 3 of 3 tomato seedlings up on CFL side, 1 of 3 LED side. Not surprising - the CFL generates more waste heat. Hopefully that feature won't dominate results in this test.
day 7: remaining 2 tomato seedlings up on LED side. No peppers yet on either side (nor expected yet).
day 13: removed the pepper pots and placed them by a heating vent... still no pepper seedlings.
day 14: And have a first pepper seedling! Put it on the LED side. (It came from the LED side.) Put the other pot on the clothes dryer for a while... There were 3 carmen pepper seeds per pot. I'm going to be really mad if my carmen pepper seeds aren't good anymore. 
day 15: Two more peppers emerged in the first (LED side) pot, none yet in the CFL side pot, so transferred one over. Have at least one pepper growing now on each side.
...day 20: All the pepper seeds eventually germinated, but not in a pattern that makes the two sides' growth easily comparable.
Progress:
Two weeks: thinned tomatoes today. Recall the 2 thinned tomato seedlings on the LED side germinated a couple days later than the other 4.
Three weeks: probably time to remove the peppers from the experiment. The random germination is just going to make the two sides hard to compare, and there really isn't room for tomatoes and peppers - I was just postponing decision of which to grow.
day 24-25: LED side tomato started to look a bit stretched. Day 24 added the 1/3 dead LED lamp to shine on that tomato (so +10W LED light), then day25 doubled the bulbs on both sides. (Needed a trip to hardware store.)
Four weeks: plants enjoying the double lights, of course. Peppers removed from experiment.
Five weeks: Experiment ends. CFL side much better tomato plant, compact & thoroughly root-bound in that pot. Decided to try growing the CFL side tomato to fruit, using one of the LED lamps. Discarded leggy underdeveloped LED-side tomato plant.
5 weeks + 2 days: a bud! 
Tue, 01/26/2010 - 20:46
#2
, Beth. Yeah, I'd like the hype about LEDs to be true. Let's find out...
Thu, 01/28/2010 - 13:58
#3
I'm sorta converted with what I've read on other bespoke LED forums, but it will be good to have the confirmation on here as well with Gisettes comparison.
I think Robs pepper grow under his UFO is showcasing what these LED's can do, this is pretty encouraging.
Sat, 01/30/2010 - 13:53
#4
I wonder if it's possible that the focused LED light beam is depressing germination.
Could just be a statistical artifact - these are small numbers of seeds, and the LEDs run cooler, and most seeds germinate faster with warmth. But - in the greens experiment, all non-germinating seeds so far were within the bright LED focused beam. The tomato seedling that came up first was the one outside the beam. Then I turned the pot so that seedling would be in the beam for light, so the remaining two seeds moved to the periphery of the beam. Two days later, they're up. But tomatoes germinate faster with heat. It should have been the other way around.
Funky.
Sun, 01/31/2010 - 17:14
#5
First week results:
Sat, 02/06/2010 - 19:48
#6
Second week results :
Thinned tomatoes today (tomatoes are at top of plate). Yes, the LED-side thinnings look smaller, but they're two days younger. On the whole, very unlike the greens experiment, the tomatoes
- Look about the same CFL vs LED side
- Both sides are creditable tomato plants for 2 weeks from seed in soil.
Don't have peppers for both sides yet. Getting very curious how they'll do CFL vs LED. Nothing else has turned out the way I expected on this experiment...
For comparison, this is a 1.5 week Jet Star (same tomato variety) grown from seed in an AG Deluxe - tons of light, warmth, hot & humid part of the year - much better growing conditions:
These seedlings - both sides - seem about on par with that plant.
Sat, 02/13/2010 - 14:14
#7
Third week results:
In complete contrast to the greens experiment, the tomatoes seem pretty comparable CFL vs LED side. The CFL plant is a little bigger, but kinda yellow. The LED plant is slightly smaller, but looks only 1 or 2 days behind developmentally. It's also a much better dark green. (Even in normal light. )
The peppers... it's impossible to say. The pepper seedlings on the LED side look great. But the eldest pepper seedling on the CFL side is one I transplanted from the LED side, and it took some damage. The younger peppers over there took up to three weeks to germinate, and the seedlings look tired from their battle to emerge.
I want a pepper plant more than I want the results of this experiment, and the rig never was big enough to grow both peppers and tomatoes anyway. I withdraw the peppers from the experiment.
The striking difference between this experiment and the greens experiment leave me wondering whether it's really the plants, or I just had a bad LED 'bulb'/light socket on the greens? But... I think the conditions were valid, and it's just the type of plants.
Fri, 02/26/2010 - 16:21
#8
Fourth week: removed peppers. Yes, there was a bad LED lamp on the greens. The tomatoes are doing pretty well. The actual week 4 pictures are above.
These are almost-5 week - now.
But - I want a discussion. I'm wondering whether there's much point to continuing with this. Neither of these tomato plants is 'bad' . But they're sure different. To continue growing for an indoor tomato harvest, I prefer the CFL side plant. Much better shape, beautifully compact. Its color isn't quite as good as the LED side.
Fri, 02/26/2010 - 16:22
#9
Fourth week: removed peppers. Yes, there was a bad LED lamp on the greens. The tomatoes are doing pretty well. The actual week 4 pictures are above.
These are almost-5 week - now.
But - I want a discussion. I'm wondering whether there's much point to continuing with this. Neither of these tomato plants is 'bad' . But they're sure different. To continue growing for an indoor tomato harvest, I prefer the CFL side plant. Much better shape, beautifully compact. Its color isn't quite as good as the LED side.
(Continued - needed to restart Firefox.)
So - if I wanted to continue this experiment to the bitter end, next I'd transplant these to matching grower's pots of a slightly larger size, bit of lime in the potting mix, lop off the bottom two branches and bury them to be approximately the same height, add a little top pile of tomato bloom nutes, maybe buy yet more light fixtures and yet another $8 CFL bulb, move up to 3 lights per side, and keep going. (The greens experiment was supposed to be done by this juncture, so I could reuse that hardware.) And keep going until... what? They both flower? At least one of them flowers?
But if I wanted tomatoes (and I do - I want tomatoes), I'd declare the CFL side a qualified winner, toss the LED side plant, repot the CFL plant (in a nice pot), add an LED lamp to its CFLs, and use the other side for my potted cucumber.Which needs to get out of my seedling shelf.
What do you think? Are there any more prizes on offer here, to continue this experiment? Seems to me all questions are answered - these CFLs blow the LEDs out of the water. Note these aren't ordinary CFLs - they're giving more growth per watt than the AG bulbs do, by a lot! Most surprised at that! But - I think they'd benefit from a little LED assist to add a touch of red.
Fri, 02/26/2010 - 16:36
#10
Perhaps there's no point in going on as you said, the CFL & LED will be too weak to grow these to maturity. You'll just be left with stretched, weak plants which won't be able to support any fruit you may get.
We've both now been hampered by defective LED's, perhaps HID wasn't so bad after all. 
Fri, 02/26/2010 - 16:49
#11
Well, I was expecting both sides to not be able to go on, as you say, Peat. But at this point, I think there's good reason to believe the CFL side can succeed. The LED side is just a waste of power.
Sun, 02/28/2010 - 14:56
#12
Five weeks: Experiment ends.
I didn't see any future in investing in more lights/fixtures to continue further - the CFL side clearly won already. Even more clear when I decanted the plants from their pots. The shorter CFL tomato was heavily root-bound. The LED side was just a fluffy little rootball that the potting mix fell off without effort. Much weaker plant despite its height. Never really wanted the height - the goal was an indoor tomato.
But. The LED side plant was always a much better color. So transferred one LED lamp over to the CFL side, and sure enough, in under 24 hours, the CFL side tomato's coloring was better. Leaves deeper green instead of yellow-greenish on the top. On the undersides, the purple/reddish freckles started clearing up, as though a vitamin deficiency were resolved.
The conclusion of this experiment isn't so simple as saying CFLs are better than same-wattage LEDs. The CFL side plant looks the same sort of shape I was trying for when I bought the Jet Star tomato seeds, because I bought a Jet Star for my father last summer. Scarcely bigger than a basketball, and so wound up you could barely find a growing tip, yet laden with mid-size tomatoes. But - I tried growing a Jet Star in my Aerogarden Deluxe, and it got leggy just like the LED side plant, and top-pruning just made it worse and worse.
It seems to be the 6500K CFLs (or probably daylight) that keeps the plant nice and compact and vigorous. And the LED lamp seems to improve its color, maybe its growth, maybe its flowering.
Will try to continue this on to a nice compact fruiting tomato.
Hi Gisette,
Looks cool! I'm not convinced that LED's are the best thing since sliced bread - please prove me wrong!
Beth