Deformed tomato seedlings
Please see the attached photo of some of the tomatoes I started from seed indoors. The tops are all deformed. It's just the tomatoes planted in this "row" of cells, the others in the adjacent cells appear to be fine. I'm wondering what happened to them, if I should scrap the plants, and if so do I need to take care not to spread a virus or something?
It’s likely the damage was caused by an herbicide (weed killer) which was sprayed outdoors. That can occur even if the seedlings are indoors or in a greenhouse. Tomatoes are very sensitive to herbicides. Even just a “whiff” causes problems.
If the seedlings were mine, I’d scrap these, then start a new batch. However, be certain to provide very bright light as soon as the seeds sprout. These particular seedlings are excessively tall (“leggy”) because of low light.
Further, begin to fertilize as soon as the first true leaves develop on the seedlings. Use a product that should be dissolved in water, but mix it at half strength. See pages 4 and 8 of this publication: “Grow Your Own Tomatoes and Tomatillos” (https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/ec1333.pdf)