My tomatoes are sick

[onesmallshift]

There's something wrong with some of my tomatoes. Most of the affected ones are in the same kind of soil and the non-affected ones are in a different, probably better quality, soil. A couple weeks ago I saw a fruit fly or something around my seedlings. How can I tell if my plants have a nutrient deficiency or if they have a leaf curl virus? The main stems are purple, the leaves are rolled down in a tube, and now the leaf stems are twisting. The leaves are a light bright green and the veins are also purple-ish. I hope they only need some fertilizer but I suspect that they have a virus.

[kitsapFG]

What you describe could be many things and possibly nothing at all (variety differences - some have purple coloring and like to twist their leaves). Need more information to zero in on what is happening. A picture would be most helpful too.

1) Where are these plants located? What has been the day and night time temps they have been experiencing? How much sun and is it direct exposure, grow lights, or a coldframe/greenhouse?
2) When were they planted? Have you repotted them subsequently?
3) What has been your watering routine? Have they been kept properly hydrated?
4) Have you been doing anything to fertilize the plants since they developed their first true set of leaves?
5) Are they all the same variety? Are the ones that are displaying the characteristics you describe all the same variety?
6) Are the plants stocky .. or are they "droopy" too?

[gardenjoinery]

My first thought is definitely nutrient deficiency, particularly with the purple. Have you tried a fish emulsion? When you say "better" soil, do you mean fresher? The older mix is often depleted, or unsanitary. You are also describing fungus gnats, I suspect. How is the temperature, and are you overwatering?

[onesmallshift]

Thanks for your replies and sorry I haven't posted any pictures yet. I have to figure out how to get them on to my computer. My new laptop doesn't have a card reader and I don't have the cable anymore. Hopefully I can post pictures later tonight or tomorrow.

The most affected are the Giant Belgian and then Ciudad Victoria but not all of both varieties are affected. The plants themselves are stocky as I have kept the grow lights a few inches above them and I sometimes put a fan on them. Also, the new growth is staying mostly vertical unless I curl it down and then it seems to stay more horizontal.They are in my basement under grow lights and the temperature doesn't get below 60 I'd say. I have been taking them outside on overcast and sunny days working up to about an hour so far.

I started them on Feb 16 and they have been repotted once or twice depending on size. I have kept them watered without being soggy but a couple days after the first repotting I didn't water them enough and they got a bit wilty. The seed starter mix (sterilized) had some fertilizer in it and when I repotted them I used a mix of seed starter and potting soil. I have also been using a diluted fertilizer on them for a couple of weeks now but it doesn't have very much phosphorous.

When I was looking online for potential causes the two most likely seemed to be phosphorous deficiency or a leaf curl virus.

[kitsapFG]

Some varieties tend to have purple in their natural coloration - but if you are not seeing this consistently in the same variety you have planted then my bet would be phosphorous deficiency - based on the additional info you provided which ruled a lot of things out. Most germinating soil mixes are quite low in nutrients and a regular program of light fertilization is a good practice I have found. I use a very weak tea of kelp/fish emulsion and water with it about every other watering for my seedlings starting from the point they get their first true leaves. If they are stocky and healthy looking over then the twisting leaves and purpling.. then I would give them a light organic fertilizer drench regularly from here on out until planted out in the garden proper.

[gardengirl72]

Heirloom tomatoes aren't always the prettiest things shall we say, but when you plant them in a pot or when they are planted out side, plant them deeply and take off any stems and leaves that will sit below the soil. They will be so happy and grow very well for you when they are in the ground.