doesn't look too serious...
its just getting used to exposure after you removed the plastic frame.

phew! thanks Wildlifebalcony I was hoping that's all it was!

If those are tomato plants they are packed in far to tightly. What size is the frame and how many plants do you have in it?

I agree with both comments above. A sudden change in exposure would affect the leaves like that. They need 3-4 feet between plants for good air circulation and sun. This will maximize fruit production. A good thick layer of mulch will also benefit them - prevents splash up diseases from the soil and evens out water uptake which prevents blossom end rot. Trim off any branches/leaves that touch the ground.

Thanks for the feedback guys, in answer to Moon_grower - the frame is 2.4m x 0.8m

there are 6 corn and 12 tomato and the rest of the box is filled with rocket, chard and peppers.

they were not so close together when i planted the seeds but my dog got in there and caused a bit of a disturbance and ended up pushing some of the tomatoes you see there closer together with the corn

should i pull and replant some of the tomato ? this is my first real attempt at growing my own veg so its really just trial and error at this stage.

@Bathgate I do have mulch on there and does seem to be doing a good job so far :)

They seem a little big for transplant. Tomatoes really hate being moved. How many plants do you have there? Last year I only had 2 plants and I had more tomatoes then I could possibly eat. I was feeding the neighborhood.

That's good about the mulch - hard to tell from the photo. Your plants look really strong and healthy

Next year if you grow them again try sowing them in a seed tray and then transplanting them into small individual three inch pots. They will eventually do best in being moved on to a 10 inch pot each when big enough, or three to a growbag. Be aware there are tall ones and low growing bush ones that grow to very different heights and are treated differently. I would buy plants if I were you if you only need a few.

For this year I'd suggest removing half the plants in your frame to allow the rest to grow properly.

You read my mind Mg. That's where I was going.

Well it is pretty obvious Bathgate :) They are so ove crowded nothing is going to grow!