“Hi! Doing good? Please, can you tell me if this is tomatoes mosaic virus or others, or simply burn from the heat lamp? How can I send you pictures, please? Thank you for caring! Anne ;-)))” Question from Anne of San Diego, California
Answer: It is hard to tell at this stage. There are points where physical damage, such as foliage burn or herbicide damage, can certainly look much like a disease. Nutrient deficiency (click here to learn about tomato nutrient deficiencies) can also look much like a disease. With that said, it is rare for seedlings to get a mosaic virus in the home. These diseases are often vectored by insects, though if you are a smoker, tobacco mosaic virus is very stable and can be transferred from contaminated cigarette tobacco to a seedling, though this is rare, too. I recommend placing the seedlings in question apart from the others, feed them, and watch them. If they pull out of it, then it was not a disease. If the foliage looks more and more diseased, then dispose of the plant. Click here to for a good look at advanced mosiac virus in tomatoes.
Black Gold Horticulturist