Purple is OK if your growing grapes, right?

[bigblue]

But I’m not, their supposed to be tomatoes, at least that’s what the seed packs said.
I am hoping someone my have a solution to my problem. This is the first time I have tried to germinate seed (tomato and hot and bell pepper) and have enjoyed some reasonable success. The seeds popped under coffee filters and were subsequently transferred to cells. In the cells for a couple weeks and potted up to 4 ½” pots. All is good… Three, four weeks pass, and now I am faced with wilting sickly plants. This is occurring only with the tomatoes, the others are growing fine. They were really healthy until a couple days ago, or maybe I am just paying more attention now. They are under 4-four foot 6500k shop lights, just inches from the bulbs. They were taken out of the cells (jiffy seed starting mix) and put into pots containing MG Organic potting mix (link attached). The leaves are pale green and curling, purple tint underneath. I the one photo, the super deep purple is caused by the flash, it is not really that purple. I read in a previous post a couple days ago some purple is normal but this seems excessive. I have been misting once a week with 1% hydrogen peroxide. They get pretty wet when misted. Any ideas? Thanks for any help you can give.

Dave

[RJGlew]

The purple colour indicates stress of some sort. Folks may talk about stress from low temperature, fertilizer uptake etc, but I wonder if you have proper lighting.

CCT of 6500k is termed `daylight' but the problem with these bulbs is they produce enough blue light, but are weak in the red zone. Better to use an equal number of warm/soft (CCT 2700) & daylight (CCT 6500) bulbs.

[JamesL]

Are you feeding them?
Are you letting them get fairly dry before watering again?
Why the repeated h2o2 spraying? I would lay off of that. It is meant to use as an eradicator not as a preventative.

[bigblue]

I have only been watering them once a week or so, after they are very dry, but long before they wilt. The MG has poultry litter in it, so I did not think it would be a good idea to feed them yet. I do have some Urban Farm Vegetable Fertilizer that I could dilute to half strength. I have hesitated to use it (any fertilizer) at such an early stage.

[JamesL]

What's the room temp like?
How long is your light cycle? Keep it 12 to 16 hours.
The yellowing bothers me, the purple does not.
Typical stresses are, water, light, temp and fert.
I think they need food as it appears you have the other bases covered.
Start with 1/4 strength every watering and up it from there. I think the potting mix has the equivalent of a starter charge in it.

[bigblue]

Thumbing back through an older thread on “Lights for starting from seed” I reached the conclusion that 65k tubular florescent bulbs were the optimal for starting plants until planting outside, should I rethink this decision? Should I interlace the 65k with a couple 27k? Numerous arguments had been made and I thought these were a good choice but my mind is always open (and occasionally absent). The lights are on 16 off 8 and the temperature is about 58 night and 70 day. Thanks for all the good ideas by the way.

[RJGlew]

Originally Posted by bigblue

Thumbing back through an older thread on “Lights for starting from seed” I reached the conclusion that 65k tubular florescent bulbs were the optimal for starting plants until planting outside, should I rethink this decision? Should I interlace the 65k with a couple 27k? Numerous arguments had been made and I thought these were a good choice but my mind is always open (and occasionally absent). The lights are on 16 off 8 and the temperature is about 58 night and 70 day. Thanks for all the good ideas by the way.

The image I have included shows the portions of the spectrum which the plant absorbs/uses. If your bulbs produce both the red & blue sprectra then you are ok, but as I mentioned earlier, "CCT of 6500k is termed `daylight' but the problem with these bulbs is they produce enough blue light, but are weak in the red zone." Warm white (CCT 2700) are rich in reds, so imho, the combination of daylight & warm white bulbs is the way to go.

[matilda'skid]

I don't like Jiffy seed starting mix. I can grow tomatoes in potting mix but Jiffy mix was awful. When I used that I had trouble. How long did they stay in that? I think your plants look a bit starved, but don't go over board because too much fertilizer is bad too.

[RJGlew]

Originally Posted by RJGlew

Warm white (CCT 2700) are rich in reds, so imho, the combination of daylight & warm white bulbs is the way to go.

Here's the spectrum produced by a warm white bulb to clarify.

[bigblue]

The sprouts stayed in the jiffy for maybe 10-14 days then into the MG in pots. I certainly can change out two of the four fluorescent bulbs for 27k, might have them in the storage garage. I will try a light dose of Urban Farm Vegetable Fertilizer mixed at ¼ strength on a couple plants and see if helps. It never occurred to me they would need fertilized this soon.

[JamesL]

Lights for starting from seed - That was a good thread. Don't swap the bulbs, you have the right ones. Hotwired knows what he is talking about - "The optimum for starting plants is 6500K of Blue light."
http://67.23.252.182/~tomatovl/showp...9&postcount=34

Look at the PAR chart in that thread as well with respect to growth vs flowering.
http://67.23.252.182/~tomatovl/showp...3&postcount=38

RJ,
You want the warm bulbs for later in the plant life to promote flowering. But that's only really applicable if you are growing them out completely indoors.

FYI - I do have 2 additional light sets in my basement with seedlings under them that have alternating warm and cool bulbs. Left over from my attempted winter basement grow 2 years ago.
Candidly - I can't really tell much difference in plant growth between the light sets in the early stages.

[RJGlew]

Originally Posted by JamesL

RJ,
You want the warm bulbs for later in the plant life to promote flowering. But that's only really applicable if you are growing them out completely indoors.

I have included diagrams showing the VL spectrum with the absorption of both chlorophyll A & B overlayed. Both A & B absorb light in the blue and the red portions of the spectrum. Chlorophyll A has 2 primary absorptions at about 430 nm (blue) and most at 660 nm (red) while B absorbs most at about 450 nm (blue) and also at 430 nm (blue) and 640 nm (red). Chlorophyll A is the plant's primary photosynthetic agent and B is an accessory pigment that passes energy on to chlorophyll A, so both are required for foliage growth.

With this said, can someone provide the source which abstracted this into a suggestion that blue spectrum is for foliage growth and red for flowering?

[RayR]

Originally Posted by bigblue

I have only been watering them once a week or so, after they are very dry, but long before they wilt. The MG has poultry litter in it, so I did not think it would be a good idea to feed them yet. I do have some Urban Farm Vegetable Fertilizer that I could dilute to half strength. I have hesitated to use it (any fertilizer) at such an early stage.

I don't see the problem having to do with your lights. I run only 65K T8 lamps and have no problems. It does look like classic nutrient deficiency symptoms to me.
The purple cast under the leave is phosphorous deficiency, the yellowing on the older growth is Nitrogen deficiency. The MG Organic soil doesn't have much NPK, not enough for 4 weeks of growth anyway. You should start fertilizing lightly after the first true leave appear.

I agree with James, lay off the H2O2 spraying, and don't spray the plants themselves if that is what you've been doing.

[Redbaron]

There are many reasons for purple to show. Many are actually beneficial long term. Colonization by mycorhizal fungi for example can cause it. The "cold treatment" can cause it. I wouldn't necessarily automatically assume it is a bad thing. I have had seedlings get MUCH more purple than that before. All it really tells you in seedlings that young is that the plants defense system has been activated. In many cases, much like we get vaccines, that defense system will stay activated and help you later.

[RayR]

Originally Posted by Redbaron

There are many reasons for purple to show. Many are actually beneficial long term. Colonization by mycorhizal fungi for example can cause it. The "cold treatment" can cause it. I wouldn't necessarily automatically assume it is a bad thing. I have had seedlings get MUCH more purple than that before. All it really tells you in seedlings that young is that the plants defense system has been activated. In many cases, much like we get vaccines, that defense system will stay activated and help you later.

I've never seen mycorhizal fungi associated with purple undersides of tomato leaves. I don't know if Dave inoculated with mycorrhizae, but the MG organic label doesn't say it has mycorrhizae added to it. Even so, I wouldn't expect mycorrhizae to have much noticeable effect at only 3-4 weeks.

Though some cultivars may naturally have elevated levels of anthocyanin at very early stages, the color should turn back to green as the plant grows. For most tomatoes it is generally a sign of stress that is causing phosphorous uptake issues at the roots. Yes, cold treatment can cause it if the soil temperature is too low causing nutrient uptake problems. Water stress, too much or too little or root diseases can cause it for the same reason. Or it could be plain old lack of available nutrients in the soil.
I'm looking at the general look of the plant besides the purpling, the yellowing of the older growth and there is a little cupping of the leaves.