The tomato plants do not show signs of disease. They do look drought stressed. From the photos, it appears the tomatoes are planted in native clay soil. Vegetable gardens need garden loam for best results. You can amend the native soil with compost or planter's mix. This will help. Another option is to build raised beds and then fill the beds with good garden soil. Be sure to mix the soil to avoid soil interface issues. Also, avoid soil amendments that have manure; these products are high in salt. Question: did you remove the bottom of the pots; are they there to protect the plants?

Here are some references:

https://extension.colostate.edu/docs/pubs/garden/07235.pdf
https://cmg.extension.colostate.edu/Gardennotes/711.pdf

Thank you.